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June 9, 2020
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https://www.sciencedaily.com/releases/2020/06/200609190730.htm
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Simple way of 'listening' to chicks could dramatically improve welfare
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A simple and low-cost method of 'listening' to chicks may allow welfare issues to be picked up at the earliest possible opportunity, according to new research.
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In commercial chicken farming, thousands of newly-hatched chicks are reared in batches. A team of animal welfare and behaviour scientists from across the UK collected acoustic recordings in 12 typical such flocks of 25,000 chicks.In nature, when uncomfortable or uncertain of their surroundings, chicks would attract the hen with a loud and distinctive distress call.In this study, the researchers demonstrated that these calls could be clearly picked up above other noises such as regular calling and farm machinery.But where previous research has linked distress calling to stress and anxiety-like states in chicks, this study also shows it could predict flock-level behaviour, future growth and mortality rate.That suggests distress calling may be an 'iceberg indicator' -- a single measure that captures a range of welfare information at once.The study, published in the Lead author Dr Katherine Herborn, Lecturer in Physiology and Behaviour at the University of Plymouth, said: "On their first day in a barn, all chicks are going to call because they are in strange surroundings. But after that they learn where to find food and water and settle into that new world, so if you are still hearing a lot of distress calling after a few days it could be a sign there is something wrong. With over 50 billion birds being produced each year, tools to support simple interventions at the right time could potentially have big impacts on welfare and quality of life for these birds."Lucy Asher, Professor in Animal Behaviour Informatics at Newcastle University and Principal Investigator on the BBSRC project, added: "By analysing the calls chicks make in their first few days of life, it seems we are able to predict weight gained and the number of deaths in the whole flock for the whole life. This means we could have a very powerful tool to help chicken welfare. What is particularly useful is that this welfare indicator can be used early on in life, whereas most chicken welfare indicators are taken later in their life when it is too late to make major improvements. As an added benefit this study shows how we can measure chick calls automatically, meaning no extra work for farmers, but more information to help them improve chicken welfare."The method used in the research involved measuring the 'spectral entropy' of the soundscape -a value that describes how sound can vary from a clear, tonal note up to white noise.As increasing numbers of chicks call in unison, the usual background noise of the farm becomes overall more tonal. This computationally simple way of counting distress calls could act as an early-warning signal to farm staff that chicks require attention and ultimately improve chick welfare across their lifetimes.The findings support previous studies on the benefits of automated monitoring of livestock for real-time warnings of emerging welfare concerns. They also emphasise the importance of using animal-centred behavioural and emotional welfare indicators alongside traditional environment and productivity monitoring on poultry farms, to improve conditions from the birds' own perspective.Dr Alan McElligott, Reader in Animal Behaviour at the University of Roehampton, added: "The results of this research show how useful vocalisations can be for monitoring welfare, and especially in an age when animal welfare needs should be central to progress in precision livestock farming."
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Agriculture & Food
| 2,020 |
June 9, 2020
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https://www.sciencedaily.com/releases/2020/06/200609095028.htm
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Oregon timber harvests don't appear to affect rare salamander, study finds
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A seven-year field experiment on 88 tree stands across Oregon's western Cascade Range found no discernable difference in the abundance and occupancy rates of rare Oregon slender salamanders on recently harvested tree stands -- clear-cuts -- compared to stands late in the harvest rotation -- older than 50 years.
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The findings are published in the journal To their surprise, the researchers found that a different, more commonly found terrestrial salamander, the Ensatina, was negatively affected by timber harvest. The study emphasizes, however, the importance of downed wood in the detection of both species. When there is dead wood on the ground, there are more Oregon slender and Ensatina salamanders, regardless of harvest stage.The Oregon slender salamander only exists on the western slopes of the Cascades, where it lives most of the year underground or burrowed in woody debris on the forest floor. This fully terrestrial salamander is primarily found in mature evergreen forests, including timber plantations.Due to concern over the effects of harvesting trees, the Oregon slender salamander is considered "sensitive" by the state of Oregon and has been petitioned for Endangered Species Act candidacy.The study comes with a recommendation from the researchers: After harvest, leave downed wood behind to provide adequate habitat for the salamander."That dead, decaying wood is essential habitat for maintaining the moisture and temperature salamanders need," said study lead author Tiffany Garcia, a wildlife ecologist in Oregon State's College of Agricultural Sciences. "We found that more downed wood meant more salamanders. If there's not enough downed wood and places for them to hide, you won't find them. The size and the type of the downed wood also matters. It needs to be in large enough pieces to keep moisture for a long time, at least until the trees grow back. If they are small pieces they'll just dry out."There hasn't been much research on the Oregon slender salamander. It only emerges and is active when there is no snow on the ground and when it's not too dry, leaving a total of a few months in the spring and the fall to find them.The study was conducted from 2013-2019. In cooperation with private and state landowners, all 88 harvest stands were randomly selected from the harvest plans of Weyerhaeuser, Port Blakely Tree Farms, the Oregon Department of Forestry and U.S. Bureau of Land Management.To be included, the stands had to have been harvested more than 50 years ago, be scheduled for harvest within three years of inclusion in the study, be larger than 80 square meters, and had verified occurrence of Oregon slender salamanders pre-harvest."One of the unique things about this study is that we did non-destructive sampling," Garcia said. "We couldn't destroy the habitat because we wanted to do repeat sampling over multiple years. This is a new way of searching for this species."
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Agriculture & Food
| 2,020 |
June 8, 2020
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https://www.sciencedaily.com/releases/2020/06/200608163451.htm
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Milkweed, only food source for monarch caterpillars, ubiquitously contaminated
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New evidence identifies 64 pesticide residues in milkweed, the main food for monarch butterflies in the west. Milkweed samples from all of the locations studied in California's Central Valley were contaminated with pesticides, sometimes at levels harmful to monarchs and other insects.
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The study raises alarms for remaining western monarchs, a population already at a precariously small size. Over the last few decades their overwintering numbers have plummeted to less than 1% of the population size than in the 1980s -- which is a critically low level.Monarch toxicity data is only available for four of the 64 pesticides found, and even with this limited data, 32% of the samples contained pesticide levels known to be lethal to monarchs, according to a study released today in Frontiers in Ecology and Evolution."We expected to find some pesticides in these plants, but we were rather surprised by the depth and extent of the contamination," said Matt Forister, a butterfly expert, biology professor at the University of Nevada, Reno and co-author of the paper. "From roadsides, from yards, from wildlife refuges, even from plants bought at stores -- doesn't matter from where -- it's all loaded with chemicals. We have previously suggested that pesticides are involved in the decline of low elevation butterflies in California, but the ubiquity and diversity of pesticides we found in these milkweeds was a surprise."Milkweed was chosen as the focus of this study because it the only food source for larval monarch butterflies in the West, and thus critical for their survival."We collected leaf samples from milkweed plants throughout the Central Valley and sent them to be screened for pesticides," Chris Halsch, lead author of the paper and a doctoral student in the University's Ecology, Evolution, and Conservation Biology program, said. "This study is the first necessary step for understanding what butterflies are actually encountering. Now we can use these data to design experiments to test hypotheses about the relative importance of pesticide use and other stressors such as climate change on local butterflies."While this is only a first look at the possible risks these pesticides pose to western monarchs, the findings indicate the troubling reality that key breeding grounds for western monarchs are contaminated with pesticides at harmful levels."One might expect to see sad looking, droopy plants that are full of pesticides, but they are all big beautiful looking plants, with the pesticides hiding in plain sight," Forister, who has been a professor int he University's College of Science since 2008, said.Western monarchs are celebrated throughout the western states and especially along the California coast where large congregations overwinter in groves of trees. Population declines also have been documented in the breeding grounds. Areas of inland California, including the Central Valley, offer important monarch breeding habitat throughout the spring and summer, including being the home to the very first spring generation which will continue the migration inland to eventually populate all western states and even southern British Columbia.Declines in the population of western monarch butterflies have been linked with various stressors, including habitat loss and degradation, pesticide use, and climate change, among others. While pesticide use has been associated with declines, previous studies had not attempted to quantify the residues that butterflies can encounter on the western landscape.The study's findings paint a harsh picture for western monarchs, with the 64 different pesticides identified in milkweed. Out of a possible 262 chemicals screened, there was an average of nine types of individual pesticides per sample and as many as 25. Agricultural and retail samples generally had more residues than wildlife refuges and urban areas, but no area was entirely free from contamination. Certain pesticides were present across all landscapes, with five pesticides appearing more than 80% of the time. Chlorantraniliprole, the second most abundant compound, was found at lethal concentrations to Monarchs in 25% of all samples.Understanding of pesticide toxicity to the monarch is limited, and is based on previously reported lab experiments. Thus we have much to learn about the concentrations encountered in field, but these new results raise concerns nonetheless. While this research focused on monarch toxicity, other pollinators and beneficial insects are also at risk from pesticide contamination throughout the landscape."We can all play a role in restoring habitat for monarchs," said Sarah Hoyle, Pesticide Program Specialist at the Xerces Society for Invertebrate Conservation and coauthor of the paper. "But it is imperative that farmers, land managers and gardeners protect habitat from pesticides if we hope to recover populations of this iconic animal."Field work, gathering plant samples, was completed last spring and summer. The lab work was completed by Nicolas Baert from the Department of Entomology and manager of the Chemical Ecology Core Facility at Cornell University. Statistical computations were completed this winter by Forister and colleague James Fordyce from the Department of Ecology and Evolutionary Biology at the University of Tennessee, Knoxville.
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Agriculture & Food
| 2,020 |
June 7, 2020
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https://www.sciencedaily.com/releases/2020/06/200607195010.htm
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Pinker flamingos more aggressive
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Bright pink flamingos are more aggressive than paler rivals when fighting over food, new research shows.
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Pink plumage is a sign of good health in lesser flamingos, and a flush of colour often means they are ready to breed.So when the birds squabble over food, the pinkest flamingos -- both male and female -- tend to push the others around.The study, by the University of Exeter and WWT Slimbridge Wetland Centre, also found the birds fight more when food is available in a small area such as a bowl -- so the findings suggest captive birds should be fed over a wide space where possible."Flamingos live in large groups with complex social structures," said Dr Paul Rose, of the University of Exeter."Colour plays an important role in this. The colour comes from carotenoids in their food, which for lesser flamingos is mostly algae that they filter from the water."A healthy flamingo that is an efficient feeder -- demonstrated by its colourful feathers -- will have more time and energy to be aggressive and dominant when feeding."Dr Rose studied the behaviour of Slimbridge's lesser flamingos in different feeding situations: at an indoor feeding bowl, a larger indoor feeding pool, and outdoors with food available in a large pool.In the outdoor pool, birds spent less than half as much time displaying aggression, while foraging time doubled (compared to when fed from a bowl)."When birds have to crowd together to get their food, they squabble more and therefore spend less time feeding," Dr Rose said."It's not always possible to feed these birds outdoors, as lesser flamingos only weigh about 2kg and are native to Africa, so captive birds in places like the UK would get too cold if they went outside in the winter."However, this study shows they should be fed over as wide an area as possible."Where possible, creating spacious outdoor feeding areas can encourage natural foraging patterns and reduce excess aggression."This research shows that zoos don't have to make huge changes to how they keep their animals to make a big, beneficial difference to animal behaviour."Lesser flamingos do not have a breeding season -- they breed when they're in good enough condition.This is often displayed by a "pink flush" in the feathers, Dr Rose said, and the birds then become paler again during the tiring days of early parenthood.He added: "This study is a great example of why I love working with WWT Slimbridge."Based on my observations, I suggested some changes -- and the keepers were willing to try them out."As a result, we get pinker, more relaxed flamingos."The colour of individual birds in the study was scored from one (mainly white) to four (mainly pink).No difference was found between males and females in rates of feeding or aggression.
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Agriculture & Food
| 2,020 |
June 4, 2020
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https://www.sciencedaily.com/releases/2020/06/200604152111.htm
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Plant detectives develop new way to trace global spread of major plant disease
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A team led by Oregon State University scientists has developed a way to potentially thwart the spread of a disease-causing bacterium that harms more than hundred plant species worldwide, an advance that could save the nursery industry billions of dollars a year.
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The research has important implications for commercial plant growers because it could help halt the spread of Agrobacterium. The bacterium causes crown-gall disease, which impacts more than 100 plant species, including fruit trees, roses, grape vine, nursery plants and shade trees. Those species have a combined value of more than $16 billion annually in the United States alone, according to the U.S. Department of Agriculture.The methods developed for the study can also potentially be applied to track diseases in humans and animals and even foodborne disease outbreaks. For example, plasmids spread antibiotic-resistant genes, a pressing problem for human and animal health.The Oregon State scientists worked with researchers at the USDA Agricultural Research Service on the study. The findings were just published in the journal "Understanding the genetic basis for how pathogens emerge and diversify in agricultural ecosystems is foundational for determining their spread and assessing risks," said Jeff Chang, a professor in Oregon State's College of Agricultural Sciences and one of the authors of the study. "These are critical to informing policies for improving plant health and preparing against disease outbreaks to increase global food security."The paper centers on plasmids, self-replicating DNA molecules that are found in Agrobacterium. Their spread amplifies the spread of disease. The plasmids of Agrobacterium have genes that give Agrobacterium the unique ability to transfer a portion of the plasmid into plant cells and genetically reprogram the host to cause crown-gall or hairy root disease.These plasmids also have genes that allow Agrobacterium to transfer the entire plasmid horizontally from one bacterium to another rather than through vertical, or parent to child, inheritance. Upon acquiring a harmful plasmid, a previously benign strain of Agrobacterium can become a novel pathogen lineage. This ability makes control of the pathogen and tracking of an outbreak difficult. Thus, to develop their tracing system, the researchers first had to understand the evolution and classification of the plasmids.Before this research, the accepted scientific view was that the frequent transfer of genetic information among plasmids and the large amount of genetic variation among Agrobacterium species made drawing evolutionary relationships between the two practically impossible. Without such information it's not possible to accurately track disease outbreaks.The researchers focused on two classes of plasmids, tumor inducing and root inducing, both of which provide Agrobacterium the ability to transfer a portion of the plasmid into plants and cause disease.Melodie Putnam, director of the Oregon State Plant Clinic, and others at OSU and USDA-ARS provided hundreds of strains with plasmids from their well-curated collection and helped analyze the large datasets.Alexandra Weisberg, lead author and a post-doctoral researcher co-mentored by Chang and Niklaus Grünwald, of the USDA-ARS Horticultural Crops Research Unit in Corvallis, sequenced 140 strains with plasmids and, surprisingly, found the plasmids all descended from just nine lineages."Armed with this extensive genetic sequencing information about how to classify plasmids and Agrobacterium, we could infer both how bacteria move among nurseries and how the plasmids move among bacteria," Weisberg said.Having whole genome sequences of Agrobacterium allowed the researchers to link nurseries on the basis of having strains with the same genome and plasmid sequences, the same genome sequence but different plasmid sequences, or different genome sequences but the same plasmid sequences, Weisberg said.They were able to track at least seven cases in which global distribution of plants contributed to the widespread transmission of a single Agrobacterium strain-plasmid combination. One of these cases included a nursery that produces plants for wholesalers and may have served as a kind of patient zero source for many outbreaks. Strains of the same genotype-plasmid combination were later identified in two other nurseries in another part of the world.With the ability to separately analyze the bacteria from the plasmid, the researchers found many cases in which plasmid transmission perpetuated disease spread. For example, they found one strain-plasmid combination that was collected in 1964. Plasmids with the same sequences were identified in strains collected 30 to 40 years later in different parts of the world.A few strains of Agrobacterium, and some plasmids, have been modified and are used in tools for studying plant function, and for introducing new traits into plants. By characterizing the variation and relationships between plasmids, findings from this study also have potential applications in optimizing these biotechnology tools or developing new ones to advance research.
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Agriculture & Food
| 2,020 |
June 4, 2020
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https://www.sciencedaily.com/releases/2020/06/200604120548.htm
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Egg-based coating preserves fresh produce
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Eggs that would otherwise be wasted can be used as the base of an inexpensive coating to protect fruits and vegetables, according to Rice University researchers.
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The Brown School of Engineering lab of materials scientist Pulickel Ajayan and colleagues have developed a micron-thick coating that solves problems both for the produce and its consumers, as well as for the environment.When the coating was applied to produce by spraying or dipping, it showed a remarkable ability to resist rotting for an extended period comparable to standard coatings like wax but without some of the inherent problems.The work by Rice undergraduate students Seohui (Sylvia) Jung and Yufei (Nancy) Cui is detailed in The coating relies on eggs that never reach the market. As the United States produces more than 7 billion eggs a year and manufacturers reject 3% of them, the researchers estimate more than 200 million eggs end up in landfills.Even before the impact of the new coronavirus, the world wasted a third of the food produced around the globe, the researchers wrote."Reducing food shortages in ways that don't involve genetic modification, inedible coatings or chemical additives is important for sustainable living," Ajayan said. "The work is a remarkable combination of interdisciplinary efforts involving materials engineers, chemists and biotechnologists from multiple universities across the U.S."Along with being edible, the multifunctional coating retards dehydration, provides antimicrobial protection and is largely impermeable both to water vapor to retard dehydration and to gas to prevent premature ripening. The coating is all-natural and washes off with water."If anyone is sensitive to the coating or has an egg allergy, they can easily eliminate it," Jung said.Egg whites (aka albumen) and yolks account for nearly 70 percent of the coating. Most of the rest consists of nanoscale cellulose extracted from wood, which serves as a barrier to water and keeps produce from shriveling, a small amount of curcumin for its antimicrobial powers and a splash of glycerol to add elasticity.Lab tests on dip-coated strawberries, avocadoes, bananas and other fruit showed they maintained their freshness far longer than uncoated produce. Compression tests showed coated fruit were significantly stiffer and more firm than uncoated and demonstrated the coating's ability to keep water in the produce, slowing the ripening process.An analysis of freestanding films of the coating showed it to be extremely flexible and able to resist cracking, allowing better protection of the produce. Tests of the film's tensile properties showed it to be just as tough as other products, including synthetic films used in produce packaging. Further tests proved the coating to be nontoxic, and solubility tests showed a thicker-than-usual film is washable.Rinsing in water for a couple of minutes can completely disintegrate it, Ajayan said.The researchers continue to refine the coating's composition and are considering other source materials. "We chose egg proteins because there are lots of eggs wasted, but it doesn't mean we can't use others," said co-corresponding author Muhammad Rahman, a research scientist in Ajayan's Rice lab, who mentored and led the team.Jung noted the team is testing proteins that could be extracted from plants rather than animal produce to make coatings.
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Agriculture & Food
| 2,020 |
June 3, 2020
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https://www.sciencedaily.com/releases/2020/06/200603151158.htm
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Researchers document the first use of maize in Mesoamerica
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An international team of researchers investigated the earliest humans in Central America and how they adapted over time to new and changing environments, and how those changes have affected human life histories and societies.
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Almost any grocery store is filled with products made from corn, also known as maize, in every aisle: fresh corn, canned corn, corn cereal, taco shells, tortilla chips, popcorn, corn sweeteners in hundreds of products, corn fillers in pet food, in soaps and cosmetics, and the list goes on.Maize is perhaps the most important plant ever domesticated by people, topping 1 billion tonnes produced in 2019, double that of rice, according to University of New Mexico Anthropology professor Keith Prufer, Principle Investigator of a team that just released new research that sheds light on when people started eating maize.Recently published research from his team in the journal "Today, much of the popularity of maize has to do with its high carbohydrate and protein value in animal feed and sugar content which makes it the preferred ingredient of many processed foods including sugary drinks. Traditionally it has also been used as fermented drink in Mesoamerica. Given its humble beginnings 9,000 years ago in Mexico, understanding how it came to be the most dominant plant in the world benefits from deciphering what attracted people to this crop to begin with. Our paper is the first direct measure of the adoption of maize as a dietary staple in humans," Prufer observed.Prufer said the international team of researchers led by UNM and University of California, Santa Barbara is investigating the earliest humans in Central America and how they adapted over time to new and changing environments, and how those changes have affected human life histories and societies."One of the key issues for understanding these changes from an evolutionary perspective is to know what the change from hunting and gathers pathways to the development of agriculture looked like, and the pace and tempo of innovative new subsistence strategies. Food production and agriculture were among most important cultural innovations in human history."Farming allowed us to live in larger groups, in the same location, and to develop permanent villages around food production. These changes ultimately led in the Maya area to the development of the Classic Period city states of the Maya between 3,000 and 1,000 years ago. However, until this study, we did not know when early Mesoamericans first became farmers, or how quickly they accepted the new cultigen maize as a stable of their diet. Certainly, they were very successful in their previous foraging, hunting, and horticultural pursuits before farming, so it is of considerable interest to understand the timing and underlying processes," he said.Radiocarbon dating of the skeletal samples shows the transition from pre-maize hunter-gatherer diets, where people consumed wild plants and animals, to the introduction and increasing reliance on the corn. Maize made up less than 30 percent of people's diets in the area by 4,700 years ago, rising to 70 percent 700 years later.Maize was domesticated from teosinte, a wild grass growing in the lower reaches of the Balsas River Valley of Central Mexico, around 9,000 years ago. There is evidence maize was first cultivated in the Maya lowlands around 6,500 years ago, at about the same time that it appears along the Pacific coast of Mexico. But there is no evidence that maize was a staple grain at that time.The first use of corn may have been for an early form of liquor."We hypothesize that maize stalk juice just may have been the original use of early domesticated maize plants, at a time when the cobs and seeds were essentially too small to be of much dietary significance. Humans are really good at fermenting sugary liquids into alcoholic drinks. This changed as human selection of corn plants with larger and larger seeds coincided with genetic changes in the plants themselves, leading eventually to larger cobs, with more and larger seeds in more seed rows," Prufer explained.To determine the presence of maize in the diet of the ancient individuals, Prufer and his colleagues measured the carbon isotopes in the bones and teeth of 52 skeletons. The study involved the remains of male and female adults and children providing a wholistic sample of the population. The oldest remains date from between 9,600 and 8,600 years ago and continues to about 1,000 years agoThe analysis shows the oldest remains were people who ate wild plants, palms, fruits and nuts found in tropical forests and savannahs, along with meat from hunting terrestrial animals.By 4,700 years ago, diets had become more diverse, with some individuals showing the first consumption of maize. The isotopic signature of two young nursing infants shows that their mothers were consuming substantial amounts of maize. The results show an increasing consumption of maize over the next millennium as the population transitioned to sedentary farming.Prufer noted, "We can directly observe in isotopes of bone how maize became a staple grain in the early populations we are studying. We know that people had been experimenting with the wild ancestor of maize, teosintle, and with the earliest early maize for thousands of years, but it does not appear to have been a staple grain until about 4000 BP. After that, people never stopped eating corn, leading it to become perhaps the most important food crop in the Americas, and then in the world."Excavations were directed by Prufer along with an international team of archaeologists, biologists, ecologists and geologists. Numerous UNM graduate and undergraduate students took part in the field research as well as collaborators with the protected area co-management team, a Belizean NGO the Ya'axche' Conservation Trust.Conditions weren't easy for the excavation teams, Prufer noted: "We did five years of fieldwork in two very remote rock shelter sites in the Bladen Nature Reserve in the Maya Mountains of Belize, a vast wilderness area that is a two-day walk from the nearest road. To work in this area we had to camp with no electricity, running water, or even cell service for a month at a time each year."Analysis was conducted at Penn State University, UNM Center for Stable Isotopes, UCSB, and Exeter University in the UK. Prufer was the project director along with his colleague Doug Kennett from UCSB. The project was funded by the Alphawood Foundation and the National Science Foundation. The study was conducted by researchers from UNM, UCSB, Pennsylvania State University, University of Exeter, The US Army Central Identification Laboratory, University of Mississippi, Northern Arizona University, and the Ya'axche Conservation Trust in Belize.Now that the research is published, the team will advance it to the next stage."New technologies allow us to look even deeper into molecular analysis through studies of ancient DNA and isotopic analysis of individual amino acids that are involved in turning food into building blocks of tissues and energy. We already have a Ph.D. students working on expanding our work to the next generation of analysis," Prufer said.
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Agriculture & Food
| 2,020 |
June 2, 2020
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https://www.sciencedaily.com/releases/2020/06/200602110112.htm
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Bees grooming each other can boost colony immunity
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Honeybees that specialise in grooming their nestmates (allogroomers) to ward off pests play a central role in the colony, finds a new UCL and University of Florence study.
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Allogroomer bees also appear to have stronger immune systems, possibly enabling them to withstand their higher risk of infection, according to the findings published in Ectoparasites (parasites that live on the outside of a host's body, such as mites) are a growing threat to honeybees worldwide, so the researchers say that supporting allogrooming behaviour might be an effective pest control strategy.Lead author Dr Alessandro Cini, who began the project at the University of Florence before moving over to UCL Centre for Biodiversity & Environment Research, said: "An ectoparasitic mite, Varroa destructor, represents a major global threat to bee colonies. By understanding how allogrooming practices are used to ward off parasites, we may be able to develop strategies to promote allogrooming behaviour and increase resilience to the parasites."Here, we found worker bees that specialise in allogrooming are highly connected within their colonies, and have developed stronger immune systems."We suspect that if more bees engaged in these allogrooming behaviours that ward off parasites, the colony as a whole could have greater immunity."Among bees, allogrooming consists of a worker using its mouth to remove debris, which may include parasites and other pathogens, from the body of another member of its colony.In bee colonies, different groups of worker bees conduct different activities -- one such specialisation is allogrooming, although it was not previously known how specialised the groomer bees are, and how their physiology may be different.The current study focused on Apis mellifera, commonly known as the western honeybee, which is the most common species of honeybee and also the world's most-used bee for both honey production and pollination in agriculture.As allogrooming would likely put the grooming bees at an elevated risk of contracting pathogens and parasites, the researchers tested their immune systems, and found that their hemolymph (like blood, but for insects) could more effectively clear out potentially harmful bacteria than the immune systems of other bees in the colony.Co-author Dr Rita Cervo from the University of Florence said: "By identifying a striking difference in the immune systems of the allogrooming bees, which are involved in tasks important to colony-wide immunity from pathogens, we have found a link between individual and social immunity."The researchers found that allogroomer bees occupy a central position in the colony's social network, as they are more connected to bees across the colony than the average bee, enabling their grooming habits to benefit a large number of bees and keep the colony as pest-free as possible.The researchers found that allogrooming is a relatively weak, transient specialty, as the groomer bees still devoted a similar amount of time to other tasks as the rest of the colony's worker bees. The researchers say this shows that bees can develop physiological differences narrowly tailored to specific tasks, while still maintaining a degree of plasticity enabling them to switch to other tasks as needed.The researchers did not detect any differences in how well the allogroomer bees could detect when other bees needed grooming, as their antennae were not more finely-tuned to relevant odours. It is possible they can detect who needs grooming in other ways, such as by noticing the 'grooming invitation dance' whereby bees shake their whole body from side-to-side.The study was supported by Progetti di Rilevante Interesse Nazionale and Unione Nazionale Associazioni Apicoltori Italiani.
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Agriculture & Food
| 2,020 |
June 1, 2020
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https://www.sciencedaily.com/releases/2020/06/200601104604.htm
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Researchers control cattle microbiomes to reduce methane and greenhouse gases
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Ben-Gurion University of the Negev (BGU) researchers have learned to control the microbiome of cattle for the first time which could inhibit their methane production, and therefore reduce a major source of greenhouse gasses.
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The findings from Prof. Itzhak Mizrahi's findings were published recently in The animal microbiome is a scientifically unexplored area. It protects against germs, breaks down food to release energy, and produces vitamins and exerts great control over many aspects of animal and human physical systems. Microbes are introduced at birth and produce a unique microbiome that evolves over time.Mizrahi and his group have been conducting a three-year experiment with 50 cows divided into two groups. One group gave birth naturally, and the other through cesarean section. That difference was enough to change microbiome development and composition microbiome of the cows from each group.This finding enabled Mizrahi's team together with Prof. Eran Halperin's group at UCLA to develop an algorithm that predicts the microbiome development and how it will evolve over time based on its present composition."Now that we know we can influence the microbiome development, we can use this knowledge to modulate microbiome composition to lower the environmental impact of methane from cows by guiding them to our desired outcomes," Mizrahi says.Prof. Mizrahi has investigated the microbiome of cows, fish and other species to address world issues shaped by climate change. Reducing methane emissions from cows will reduce global warming. Engineering healthier fish, which is another of Mizrahi's projects, is especially important as the oceans empty of fish and aquaculture becomes the major source of seafood.
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Agriculture & Food
| 2,020 |
May 28, 2020
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https://www.sciencedaily.com/releases/2020/05/200528172000.htm
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Two bacteria allow spittlebugs to thrive on low-nutrient meals
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A new study examines the symbiotic relationship between two types of bacteria and spittlebugs that helps the insect live on very low-nutrient food. The bacteria use a metabolic "trick" also employed by cancer cells to create the right conditions for converting the poor food into the necessary building blocks for survival.
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The study, "Syntrophic Splitting of Central Carbon Metabolism in Host Cells Bearing Functionally Different Symbiotic Bacteria," published April 29 in the journal of the Spittlebugs get their name from the bubbly spit they create in plant branches. The clusters of spit keeps them from drying out and allow them to hide from predators. There they feed on xylem plant sap, a very low-value food; xylem transports water and minerals from the plant's roots to its leaves."No animal should be able to subsist on xylem alone -- it's really just water and a few nutrients," said lead author Nana Ankrah, a postdoctoral researcher in the lab of Angela Douglas, the Daljit S. and Elaine Sarkaria Professor of Insect Physiology and Toxicology in the Department of Entomology in the College of Agriculture and Life Sciences.The answers to how these bugs survive lie in two types of bacteria that live in separate spittlebug organs, called bacteriomes; one is red, the other orange. Other similar insects that feed on plant sap have just one bacterial partner to help produce high-quality amino acids, the building blocks of proteins."We wanted to understand if there were any advantages to having two bacterial symbionts on this very poor diet," Ankrah said.The researchers collected local spittlebugs, removed their red and orange bacteriomes, incubated the bacteria separately in glucose, and ran metabolic experiments and computer model simulations.They discovered that the red bacteriome uses a process known as aerobic glycolysis to process glucose, from which the bacteria synthesize seven essential amino acids. Two byproducts of this process, pyruvate and lactate, are assimilated by the orange bacteriome to create ATP molecules, which make energy for cells. The energy boost from ATP allows the bacteria in the orange bacteriome to produce three additional essential amino acids that require a great deal of energy to produce.Having two bacterial partners instead of one works because they have this method for exchanging products from one bacterium to the other to increase the overall energy available to them, Ankrah said.The researchers were surprised to find aerobic glycolysis occurring in these bacteria, as cancer cells employ the same process to survive, with a subset of cancer cells undergoing glycolysis and producing pyruvate and lactate, which another subset of cancer cells consumes to create energy."To our knowledge," Ankrah said, "our article is the first demonstration of aerobic glycolysis as a strategy to facilitate amino acid production in symbioses."Future studies will investigate glycolysis in other insect and bacteria partnerships, he said.Douglas is co-senior author with Ludmilla Aristilde, an adjunct associate professor in the Department of Biological and Environmental Engineering in CALS.The study was funded by the National Science Foundation.
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Agriculture & Food
| 2,020 |
May 28, 2020
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https://www.sciencedaily.com/releases/2020/05/200528160530.htm
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Changes in cropping methods, climate decoy pintail ducks into an ecological trap
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After a severe drought gripped the Prairie Pothole Region of the U.S. and Canada in the 1980s, populations of almost all dabbling duck species that breed there have recovered. But not northern pintails. Now, a new study by a team of researchers suggests why -- they have been caught in an ecological trap.
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The Prairie Pothole region straddles the U.S.-Canada border and sprawls from central Iowa in the south to Alberta in the north, covering a large swath of Minnesota, South Dakota, North Dakota, Manitoba and Saskatchewan in between."With increasing cropland cover in the region, pintails have been selecting for cropland over scarce alternative nesting habitat, probably because it is similar to the native mixed-grass prairie they evolved to nest in," said lead researcher Frances Buderman, Penn State. "That behavior results in fewer pintails the following year due to nest failures from predation and agricultural practices."The U.S. Fish and Wildlife Service's North American Waterfowl Management Plan calls for more than 4 million pintails, but recent estimates are only half of that. The reason pintails are not thriving like other dabbling ducks, according to Buderman, assistant professor of quantitative wildlife ecology in the College of Agricultural Sciences, is that they are being "misled" by modern cropping methods and climate change into choosing risky nesting habitat.Also called puddle ducks, dabbling ducks frequent shallow waters such as flooded fields and marshes. They feed by tipping up rather than diving. There are 38 species of dabbling ducks -- they float high in the water and are swift fliers.By their very nature, pintails may be vulnerable to the ecological trap, Buderman explained. Despite being an early-spring nester -- a quality that typically would allow for reproductive "plasticity" to climatic conditions -- pintails have demonstrated inflexible breeding behavior, such as being unwilling or unable to delay nest initiation and being less likely to renest than most other waterfowl."Inflexible breeding behavior may result in greater vulnerability to unpredictable weather events and changes in climactic conditions," she said. And given their preference for nesting among landscapes of grass-like, low-lying cover, pintails readily nest in fields of stubble in untilled agricultural fields. "Unlike other ducks that generally avoid nesting in stubble, pintails in the Prairie Pothole Region commonly select crop stubble nest sites and often select it over remnant patches of grass and other cover."Pintails often initiate nests before remaining stubble fields are worked by farmers in the spring, making nests vulnerable to mechanical spring tilling and planting of remaining standing stubble, Buderman explained. That can destroy a large percentage of initial nests. Exacerbating the effect of pintail selections over time, the amount of land in the Prairie Pothole Region annually tilled for spring-seeded crops has increased by approximately 34% since 1959.Another factor that is contributing to pintails' decline, researchers contend, is a trend in some areas of the Prairie Pothole Region to manipulate drainage to consolidate surface water into larger and deeper wetlands that dry out less frequently and have more surface-water connections to other wetlands.Those drainage practices make mowing around ponds easier for farmers, and most waterfowl species have coped thus far, but it hasn't been good for pintails. Wildlife scientists suspect the birds need the smaller, shallower, ephemeral ponds with which they evolved. For reasons not clearly understood, pintails appear to be particularly sensitive to changes in the number of productive, small wetlands that have occurred across the Prairie Pothole Region.Buderman pointed out that funding partner Delta Waterfowl is working hard to restore these valuable seasonal wetlands on the U.S. side of the region by establishing a Working Wetlands program in the U.S. Department of Agriculture via the federal farm bill.To reach their conclusions, researchers used more than 60 years of data from the U.S. Fish and Wildlife Service and the Canadian Wildlife Service, which have monitored spring population sizes for North American waterfowl since 1955. They published their results in the That information is organized into regions that reflect both habitat differences and political boundaries. For many decades, waterfowl have been counted on both sides of the border by aerial crews flying fixed-wing aircraft along established transect lines at low altitude, while simultaneously, ground counts are conducted at ponds on a subset of air-surveyed areas.To analyze population dynamics, researchers developed a complex model to deal with a huge dataset that took days to run on a powerful computer, which calculated a "breeding pintail count" for the survey period. The model -- which also took into account precipitation, climatic conditions during the breeding season and pond dynamics -- allowed researchers to identify the relative influence of long-term changes in climate and land use on both the selection and quality of habitat for pintails in the Prairie Pothole Region.
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Agriculture & Food
| 2,020 |
May 28, 2020
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https://www.sciencedaily.com/releases/2020/05/200528115813.htm
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Beyond the garnish: Will a new type of produce get the microgreen light?
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Microgreens. They're leafy green vegetables that are relatively new to the dining room, but a study by a Colorado State University team indicates that they will be welcome company at the table.
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"You've probably heard of sprouts and baby greens," said lead researcher and registered dietitian nutritionist Sarah Ardanuy Johnson, an assistant professor and director of the Functional Foods & Human Health Laboratory in CSU's Department of Food Science and Human Nutrition. "These are somewhere in the middle."Microgreens are young and tender leafy greens of most vegetables, grains, herbs and flowers that are harvested when their first leaves appear. Their rapid maturity of a few weeks and affinity for controlled-environment agriculture (also known as indoor farming) means they use very little water and can be harvested quickly. It makes them a model of sustainability: They can be grown indoors, year-round, in cities and rural communities, in greenhouses, warehouses, vertical farms and even homes."I came across microgreens and had never heard of them before," said Johnson, who initially studied environmental science and ecology as an undergraduate before realizing her true academic passion was in nutrition and food science. "The need for our food to be more sustainable is greater than ever. I love the idea that they can be grown in an urban environment, indoors in big cities and smaller towns. We can't just grow everything in the soil outside anymore, and we need to conserve what natural resources we still have."Johnson described them as leafy greens that pack a punch. They carry fewer food safety concerns than sprouts because they are grown in an environment with less moisture and, unlike sprouts, the roots of microgreens are removed during harvest. Nutritionally, they have been shown to have higher concentrations of phytochemicals and nutrients like beta-carotene (which can be converted to Vitamin A) than mature plants."Vitamin A deficiency is the leading cause of blindness worldwide," Johnson said, explaining that microgreens may become a key food source for preventing nutrient deficiencies and promoting global health and environmental sustainability. "That potential is pretty cool."But she and her fellow researchers wanted to find out if microgreens are acceptable to consumers, and possible factors in how much consumers like or dislike them. They sought to understand if microgreens' appearance, taste and other considerations make them an appealing addition to people's plates. The answer? Signs point to more and more people exhibiting a microgreen palate.Results of the study were published in March in the "Some people call them 'vegetable confetti' or 'funfetti' because they're small, colorful and flavorful," Johnson said, adding that they have historically been used as a garnish or topping in restaurants.The red-colored ones -- beet, cabbage and amaranth -- received top marks for appearance, but broccoli, red cabbage, and tendril pea got the highest grades overall. Arugula was ranked lowest, on average, likely due to its somewhat spicy and bitter flavor, although many people did like the taste. Overall, microgreens that rated highly for appearance, flavor and texture also scored lower on factors like astringency, bitterness, heat and sourness. Food neophobia, or the fear of trying new foods, was found to also be an important factor driving consumer acceptability."But they were all liked well enough that people said they would consume them and purchase them," Johnson said. "I feel like they should be used more as a vegetable and not just a garnish. That's part of the reason why I wanted to do this study."In fact, that was one of her key goals in launching the research: Can the appeal of microgreens lead to more popularity, more demand, more production and more grocery stores carrying them? Such products can be expensive due to markup and packaging."But people's mindsets are changing," Johnson said. "People don't want to buy something that's going to just end up in the landfill. They are looking for something that can benefit their health and the environment."Participants said factors they would consider in buying microgreens included familiarity and knowledge, cost, access/availability and freshness/shelf-life.For the research project, Johnson teamed up with Steven Newman, a professor and greenhouse crops specialist in CSU's Department of Horticulture and Landscape Architecture. Johnson found him online in her quest to find a collaborator with expertise in greenhouse crops; Newman has provided leafy greens grown in the Horticulture Center to campus dining halls. Newman's team grew the microgreens used in the study with help from Johnson's team, in a classic example of the type of cross-disciplinary research that's on the rise at CSU."This has been a fun project with fruitful outcomes," Newman said. "This is how transdisciplinary research is supposed to work."Study co-author Marisa Bunning, a food science professor and Extension food safety specialist, has become a microgreens fan and now grows them at home. Laura Bellows, an associate professor with expertise in public health and health behaviors, helped assess factors contributing to consumer acceptability, such as food neophobia.Other members of Johnson's team included Hanan Isweiri, Newman's former postdoctoral fellow; first author Kiri Michell, one of Johnson's graduate students; graduate student Michelle Dinges; undergraduate Lauren Grabos; Associate Professors Michelle Foster and Tiffany Weir of the Department of Food Science and Human Nutrition; Assistant Professors Adam Heuberger and Mark Uchanski, Associate Professor Jessica Prenni, and Professor Henry Thompson of the Department of Horticulture and Landscape Architecture; and Assistant Professor Sangeeta Rao of the Department of Clinical Sciences.Experts say that by 2050, there will be more than 10 billion people in the world to feed, making it more important than ever to think about ways to produce and grow nutritious food, as well as diversify the food supply in a sustainable way."This was a very exciting, interdisciplinary study, and I am glad I was able to take part and help lead it," Michell said. "I look forward to more research regarding these small but mighty greens and their role in our food supply and on human health.""I don't know that we could have done the advanced interdisciplinary research without Kiri's hard work and leadership," Johnson said. "But this was truly a team effort."Michell noted that The Foundry dining hall on the CSU campus has started using microgreens in some of its dishes, and even has a viewing window where students can see them being grown.The large collaboration aims to advance research on microgreens, and to increase knowledge of microgreens and their integration into the global food system. The group is conducting additional research, such as examining the feasibility, tolerability and potential health impacts of daily microgreen consumption at a higher dose (two cups per day, which is a typical serving size for leafy green vegetables), and comparing the nutritional value of microgreens to that of their more mature counterparts.The Department of Food Science and Human Nutrition is part of CSU's College of Health and Human Sciences.
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Agriculture & Food
| 2,020 |
May 27, 2020
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https://www.sciencedaily.com/releases/2020/05/200527123405.htm
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Patterns in crop data reveal new insight about plants and their environments
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A recently published study led by Iowa State University scientists applied a fresh perspective to vast amounts of data on rice plants to find better ways to predict plant performance and new insights about how plants adapt to different environments.
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The study, published in the academic journal "An organism's traits are determined by a combination of its genome, its environment and circumstances unique to that organism," said Tingting Guo, the first author of the paper and a research scientist in agronomy. "These are all complex factors. We're trying to see how to gain a deeper understanding of the process so that we can move up the pyramid of data: information, knowledge and wisdom. Accurately predicting traits is a natural extension of applying that wisdom."The study analyzed data from 174 rice plants grown in nine different environments across Asia. The researchers analyzed the dataset using methods they'd previously developed for sorghum and found temperatures early in the growth of the plants play a major role in determining the length of time the rice plants flower, called flowering time. Coupled with genomic data, the researchers used this observation to develop an index from the temperature profile between nine and 50 days after planting to predict flowering time.The study's findings hinge on the ability of the researchers to apply innovative analysis techniques to large, previously available datasets, rather than generating new data."Our starting point was data that already existed," said Xianran Li, an adjunct associate professor. "But we spent our time extracting new information from that data and taking the next critical step to explore the connection with a much larger dataset."The analysis also found patterns in the geographic distribution of certain rice genetic haplotypes, or sets of DNA combinations that tend to be inherited together, among roughly 3,000 diverse rice plants. These geographic patterns revealed preferential adaptation to different temperature zones, Guo said. Regions with lower temperature were dominated by haplotypes sensitive to temperature changes, while the equatorial region had a majority of haplotypes that are less responsive to temperature, according to the study.Yu and his colleagues have applied their data analysis methods to sorghum and rice plants, and he said similar approaches should carry over to corn and soybeans as well.The fundamental question motivating the research is how the complex genotype-environment interplay gives rise to phenotypic variation, Yu said. The team proposed a conceptual model to connect gene and environment together."It is time to bring the inseparable environmental context into how we define the effects of genes and gene networks. This model bridges the gaps among various research in individual gene discovery, field-level phenotypic plasticity, and genomic diversity and adaptation," Yu said. "We think this conceptual model also serves as a broad framework to move plant breeding forward."Funding for the research came from the ISU Plant Sciences Institute and the ISU Raymond F. Baker Center for Plant Breeding.
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Agriculture & Food
| 2,020 |
May 27, 2020
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https://www.sciencedaily.com/releases/2020/05/200527164331.htm
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Exchange of arms between chromosomes using molecular scissors
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The CRISPR/Cas molecular scissors work like a fine surgical instrument and can be used to modify genetic information in plants. The research teams of Professor Holger Puchta of Karlsruhe Institute of Technology (KIT) and Professor Andreas Houben from the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) in Gatersleben have now been the first to not only exchange single genes, but to recombine entire chromosomes with the CRISPR/Cas technology. In this way, desired properties can be combined in crops. Their work using the thale cress model plant is reported in
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For thousands of years, humans have taken advantage of the fact that the genetic material of organisms changes by evolution. They cultivate crops that produce high yields, are aromatic or resistant against diseases, pests, and extreme climatic conditions. For this purpose, they choose plants with various favorable properties and crossbreed them. This approach, however, is very time-consuming. Moreover, it is impossible to prevent disadvantageous traits from entering the plants.Molecular biologist Professor Holger Puchta studies how plants can be cultivated more quickly and more precisely. For his CRISBREED project, he received an Advanced Grant of the European Research Council (ERC) in the amount of EUR 2.5 million. Holger Puchta is considered a pioneer of genome editing. He uses molecular scissors to specifically modify the DNA (deoxyribonucleic acid) that carries the genetic information in crops. With the help of this CRISPR/Cas technology, genes can be removed, inserted, or exchanged easily. CRISPR/Cas stands for a certain section on the DNA (CRISPR -- Clustered Regularly Interspaced Short Palindromic Repeats) and an enzyme (Cas) that recognizes this section and cuts the DNA precisely at this point. Crops produced by genome editing do not contain any DNA, which is why they are not to be equated with classical genetically modified organisms.Within CRISBREED, researchers of the Chair for Molecular Biology and Biochemistry of KIT's Botanical Institute headed by Professor Holger Puchta, in cooperation with Professor Andreas Houben from IPK, Gatersleben, have now achieved first decisive progress in using the molecular CRISPR/Cas scissors: For the first time, they have exchanged arms between chromosomes of the thale cress model plant (Arabidopsis thaliana) with the help of the Cas9 protein originating from the Staphylococcus aureus bacterium. "The genome consists of a certain number of chromosomes, on which the individual genes are arranged in fixed order," Puchta explains. "So far, CRISPR/Cas has enabled modifications of single genes only. Now, we can modify and recombine entire chromosomes." These novel chromosomes are then heritable.The findings presented in
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Agriculture & Food
| 2,020 |
May 26, 2020
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https://www.sciencedaily.com/releases/2020/05/200526145308.htm
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Honeybees: Pesticides disrupt nursing behavior and larval development
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A newly developed video technique has allowed scientists at Goethe University Frankfurt at the Bee Research Institute of the Polytechnical Society to record the complete development of a honey bee in its hive for the first time. It also led to the discovery that certain pesticides -- neonicotinoids -- changed the behaviour of the nurse bees: researchers determined that they fed the larvae less often. Larval development took up to 10 hours longer. A longer development period in the hive can foster infestation by parasites such as the Varroa mite.
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Honey bees have very complex breeding behaviour: a cleaning bee cleans an empty comb (brood cell) of the remains of the previous brood before the queen bee lays an egg inside it. Once the bee larva has hatched, a nurse bee feeds it for six days. Then the nurse bees caps the brood cell with wax. The larva spins a cocoon and goes through metamorphosis, changing the shape of its body and developing a head, wings and legs. Three weeks after the egg was laid, the fully-grown bee hatches from the cocoon and leaves the brood cell.Using a new video technique, scientists at Goethe University Frankfurt have now succeeded for the first time in recording the complete development of a honey bee in a bee colony at the Bee Research Institute of the Polytechnical Society. The researchers built a bee hive with a glass pane and were thus able to film a total of four bee colonies simultaneously over several weeks with a special camera set-up. They used deep red light so that the bees were not disturbed, and recorded all the movements of the bees in the brood cells.The researchers were particularly interested in the nursing behaviour of the nurse bees, to whose food (a sugar syrup) they added small amounts of pesticides known as neonicotinoids. Neonicotinoids are highly effective insecticides that are frequently used in agriculture. In natural environments, neonicotinoids arrive in bee colonies through nectar and pollen collected by the bees. It is already known that these substances disturb the navigational abilities and learning behaviour of bees. In a measure criticised by the agricultural industry, the European Union has prohibited the use of some neonicotinoids in crop cultivation.Using machine learning algorithms developed by the scientists together with colleagues at the Centre for Cognition and Computation at Goethe University, they were able to evaluate and quantify the nursing behaviour of the nurse bees semi-automatically. The result: even small doses of the neonicotinoids Thiacloprid or Clothianidin led to the nurse bees feeding the larva during the 6-day larval development less frequently, and consequently for a shorter daily period. Some of the bees nursed in this manner required up to10 hours longer until the cell was capped with wax."Neonicotinoids affect the bees' nervous systems by blocking the receptors for the neurotransmitter acetylcholine," explains Dr Paul Siefert, who carried out the experiments in Professor Bernd Grünewald's work group at the Bee Research Institute Oberursel. Siefert: "For the first time, we were able to demonstrate that neonicotinoids also change the social behaviour of bees. This could point to the disruptions in nursing behaviour due to neonicotinoids described by other scientists." Furthermore, parasites such as the feared Varroa mite (Varroa destructor) profit from an extended development period, since the mites lay their eggs in the brood cells shortly before they are capped: if they remain closed for a longer period, the young mites can develop and multiply without interruption.However, according to Siefert, it still remains to be clarified whether the delay in the larval development is caused by the behavioural disturbance of the nurse bee, or whether the larvae develop more slowly because of the altered jelly. The nurse bees produce the jelly and feed it to the larvae. "From other studies in our work group, we know that the concentration of acetylcholine in the jelly is reduced by neonicotinoids," says Siefert. "On the other hand, we have observed that with higher dosages, the early embryonal development in the egg is also extended -- during a period in which feeding does not yet occur." Additional studies are needed to determine which factors are working together in these instances.In any case, the new video technique and the evaluation algorithms offer great potential for future research projects. In addition to feeding, behaviours for heating and construction were also able to be reliably identified. Siefert: "Our innovative technology makes it possible to gain fundamental scientific insights into social interactions in bee colonies, the biology of parasites, and the safety of pesticides."
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Agriculture & Food
| 2,020 |
May 26, 2020
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https://www.sciencedaily.com/releases/2020/05/200526134651.htm
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Bumblebees speed up flowering
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Spring has sprung earlier than ever before this year, accompanied by temperatures more typical of early summertime. Many plants were already in full bloom by mid-April, about three to four weeks earlier than normal. These types of seasonal anomalies are becoming increasingly frequent due to climate change, and the resulting uncertainty threatens to disrupt the timing of mutualistic relationships between plants and their insect pollinators.
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A research team led by ETH Professors Consuelo De Moraes and Mark Mescher has now discovered that one peculiar bumblebee behaviour may help to overcome such challenges by facilitating coordination between the bees and the plants they pollinate. The group has found that bumblebee workers use their mouth parts to pinch into the leaves of plants that haven't flowered yet, and that the resulting damage stimulates the production of new flowers that bloom earlier than those on plants that haven't been given this "nudge."Their study has just been published in the journal The researchers first noticed the behaviour during other experiments being undertaken by one of the authors, Foteini Pashalidou: pollinators were biting the leaves of test plants in the greenhouse. "On further investigation, we found that others had also observed such behaviours, but no one had explored what the bees were doing to the plants or reported an effect on flower production," Mescher explains.Following up on their observations, the ETH researchers devised several new laboratory experiments, and also conducted outdoor studies using commercially available bumblebee colonies -- typically sold for the pollination of agricultural crops -- and a variety of plant species.Based on their lab studies, the researchers were able to show that the bumblebees' propensity to damage leaves has a strong correlation with the amount of pollen they can obtain: Bees damage leaves much more frequently when there is little or no pollen available to them. They also found that damage inflicted on plant leaves had dramatic effects on flowering time in two different plant species. Tomato plants subjected to bumblebee biting flowered up to 30 days earlier than those that hadn't been targeted, while mustard plants flowered about 14 days earlier when damaged by the bees."The bee damage had a dramatic influence on the flowering of the plants -- one that has never been described before," De Moraes says. She also suggests that the developmental stage of the plant when it is bitten by bumblebees may influence the degree to which flowering is accelerated, a factor the investigators plan to explore in future work.The researchers tried to manually replicate the damage patterns caused by bees to see if they could reproduce the effect on flowering time. But, while this manipulation did lead to somewhat earlier flowering in both plant species, the effect was not nearly as strong as that caused by the bees themselves. This leads De Moraes to suggest that some chemical or other cue may also be involved. "Either that or our manual imitation of the damage wasn't accurate enough," she says. Her team is currently trying to identify the precise cues responsible for inducing flowering and characterising the molecular mechanisms involved in the plant response to bee damage.The ETH research team was also able to observe the bees' damaging behaviour under more natural conditions, with doctoral student Harriet Lambert leading follow-up studies on the rooftops of two ETH buildings in central Zurich. In these experiments, the researchers again observed that hungry bumblebees with insufficient pollen supplies frequently damaged the leaves of non-blooming plants. But the damaging behaviour was consistently reduced when the researchers made more flowers available to the bees.Furthermore, it was not only captive-bred bumblebees from the researchers' experimental colonies that damaged plant leaves. The investigators also observed wild bees from at least two additional bumblebee species biting the leaves of plants in their experimental plots. Other pollinating insects, such as honeybees, did not exhibit such behaviour, however: they seemed to ignore the non-flowering plants entirely, despite being frequent visitors to nearby patches of flowering plants."Bumblebees may have found an effective method of mitigating local shortages of pollen," De Moraes says. "Our open fields are abuzz with other pollinators, too, which may also benefit from the bumblebees' efforts." But it remains to be seen whether this mechanism is sufficient to overcome the challenges of changing climate. Insects and flowering plants have evolved together, sharing a long history that strikes a delicate balance between efflorescence and pollinator development.However, global warming and other anthropogenic environmental changes have the potential to disrupt the timing of these and other ecologically important interactions among species. Such rapid environmental change could result in insects and plants becoming increasingly out of sync in their development, for example. "And that's something from which both sides stand to lose," Mescher says.
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Agriculture & Food
| 2,020 |
May 26, 2020
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https://www.sciencedaily.com/releases/2020/05/200526091355.htm
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Birds, bees and butter: Biodiversity critical for shea crop in Africa
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Shea yields are likely to benefit from a diversity of trees and shrubs in parkland habitats in West Africa, according to a new study led by scientists from Trinity College Dublin. The findings have important implications for managing a crop that is typically harvested and sold by women in rural areas, and which helps finance education for children.
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Shea trees (Shea trees benefit from bees moving pollen between their flowers to produce fruit, but the new study -- just published in the The shea parklands are a long-established traditional food and fuel wood production system, but with growing population pressure and the introduction of the tractor, management has moved away from a shifting cultivation and pastoralist system to more intensive 'permanent' agriculture. This has resulted in a loss of fallow land and contributed to a degraded and fragmented landscape with a lower diversity of plants, which makes life hard for insect pollinators in the Sahel.The study recommends that when areas are cleared for cultivation, shrubs and trees that are beneficial to the local pollinators should be retained. Furthermore, measures to conserve pollinators in the region should target both honeybees and other bee species.The researchers involved in this new study -- funded by a Darwin Initiative grant -- came together from Trinity and INGOs, BirdLife International and the RSPB, and conducted the work with local farmers, NGOs and academics in Burkina Faso, West Africa. The findings will be used to inform local conservation.Jane Stout, Professor in Botany at Trinity, and a senior author of the study, said:"In the face of a global biodiversity crisis, studies like this are crucial for demonstrating the everyday importance of biodiversity. We have shown that more biodiverse parklands support more pollinators, and this makes crops more productive -- benefitting local peoples' livelihoods and well-being."Dr Aoife Delaney, lead researcher, said:"Shea plays a special economic role in Burkina Faso. It is generally harvested and sold by women in rural areas and generates an income that is particularly linked to funding children's education, bringing wider societal benefits. The fruits ripen at a time of year when both food and money are scarcest, helping to tide families over."Nutritionally, shea provides essential nutrients and fats that are in short supply during the dry season, and safe-guarding the shea crop in the long-term is important for food security. Supporting pollinators and diverse plant communities in shea parklands also has secondary benefits as the majority of the trees and shrubs there benefit from pollination, including other fruit crops and species that are important for maintaining soil fertility."Already, BirdLife International and the Burkinabe partner Naturama are working to change the way shea resources are managed within the landscape and are promoting a farmer-led approach built on simple, low cost changes in land management to enhance biodiversity on-farm. This includes natural regeneration and planting of native trees and shrubs with multiple benefits for people, livestock, insects and birds; replacing agrochemicals with locally produced mulch and compost; and introducing apiculture for pollination and food / income.Together, the international team has produced biodiversity guidelines for Parkland Management that were adopted by the Global Shea Alliance, a 500-strong member organisation, which aims to increase sustainability across the shea value chain, both in the food and cosmetic industries. And, together with local partners, the team has been educating and increasing awareness around the important role of pollinators and undertaking training and capacity building with Burkinabe communities and in schools throughout the region.Elaine Marshall, project manager, said: "Our work supports the theory that when we improve plant diversity on farms we see an increase in pollinators and shea yield. We believe a landscape approach which protects these ecosystem goods and services also reduces the vulnerability of human populations across the shea belt. This work demonstrates the potential for ecosystem restoration to deliver healthier and more resilient stocks of natural capital, enhanced pollination services and improved capacity for adapting to the impacts of climate change. Restoring 'nature' should be considered as a core component of successful development aid strategy."Professor Juliet Vickery, RSPB's Centre for Conservation Science, said: "Retaining shrubs and trees can have multiple other benefits. It can help combat desertification in an area extremely vulnerable to the impact of climate change and provide vital habitat for many of Europe's summer migrant birds that winter or stop over in the Shea zone on their way to and from sub-Saharan Africa."
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Agriculture & Food
| 2,020 |
May 22, 2020
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https://www.sciencedaily.com/releases/2020/05/200522113824.htm
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Parasitic wasp discovery offers chemical-free pest control for growers
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A species of parasitic wasp discovered by chance could provide growers with a chemical-free way of controlling a major pest.
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Researchers made the discovery when the wasps appeared mysteriously in colonies of cabbage stem flea beetles (CSFB) they were studying to test feeding preferences on oilseed rape.The wasps appeared even though the beetles were confined to potted oilseed rape plants inside micro-perforated bags.Further exploration revealed that the colonies of around 3000 beetles collected from three sites around Norfolk had been infected by a parasitic wasp that lays eggs within the beetle's body.Genetic sequencing and enquiries by the Natural History Museum, UK, and the Swedish Museum of Natural History identified the wasp as an obscure species called Microctonus brassicae which was first reported in 2008 with no further identifications until now.The study carried out by researchers at the John Innes Centre is the first English published description of this parasitoid of the adult CSFB.Experiments showed that within controlled conditions the presence of wasps in sufficient numbers led to the collapse of CSFB colonies.Beetle hosts are rendered sterile and die after the wasp larvae emerge from the body after passing through its digestive system. The short generation time of 43.5 days from egg to adult means it would be possible to rapidly rear multiple generations in controlled conditions.The study raises the possibility of employing Microctonus Brassicae and other species of genetically similar parasitic wasps as a biocontrol to protect oilseed rape and a range of commercially important crops prone to attack by CSFB.The beetle is a major threat to oilseed rape, particularly the winter crop, throughout the UK and Europe. It causes characteristic damage known as "shot-holing" to leaves often resulting in crop failure or poor crop establishment.The beetle has become a prominent pest in the UK, particularly in East Anglia, and surrounding counties following the European ban on neonicotinoid seed treatment use in flowering crops.The ban on these and other systemic pesticides followed research linking their use to decline in pollinators. Further legislation in 2019 upgraded the ban to include other broad-spectrum pesticides.With the removal of seed treatments for oilseed rape the numbers of CSFB and the damage they cause have increased. Figures for 2014 value damage at £23million with an approximate loss of 3.5% of the national crop area of winter oilseed rape to CSFB.The estimated best-case crop production for 2020/21 is 1.26 million tonnes, a year on year decline of 489,000 tonnes, putting the future of the valuable UK rapeseed crop in doubt.Using beneficial insects for biocontrol has been investigated in the past with five species of parasitoid wasps found to target CSFB. But these have demonstrated limited effectiveness and found to be economically unnecessary while the now banned pesticides were in use.Under captivity in this study M. brassicae rate of parasitism was greater than 44%. The research suggests that the wasp may have the potential to deliver positive effects under field conditions.Further research has been performed by Rothamsted Research to look at wasp presence and parasitism levels across the UK. Agricultural practices such as promotion of field margins, beetle banks and conservation headland may provide habitats to support the beneficial parasitoids."Something that was initially very annoying leading to the collapse of our research colonies has turned out to be fortunate," says lead author Dr Rachel Wells of the John Innes Centre. "It offers the possibility of using parasitoid wasps as bio-controls for farmers and growers of oilseed rape and brassica vegetables against cabbage stem flea beetle as part of an integrated pest management approach."The research: The potential of the solitary parasitoid Microctonus brassicae for the biological control of the adult cabbage stem flea beetle, Psylliodes chrysocephala is in the journal
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Agriculture & Food
| 2,020 |
May 20, 2020
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https://www.sciencedaily.com/releases/2020/05/200520191413.htm
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How fishmeal and oil alternatives can support aquaculture growth
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As the world increasingly turns to aqua farming to feed its growing population, there's no better time than now to design an aquaculture system that is sustainable and efficient.
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Researchers at UC Santa Barbara, the University of Tasmania and the International Atomic Agency examined the current practice of catching wild fish for forage (to feed farmed fish) and concluded that using novel, non-fishmeal feeds could help boost production while treading lightly on marine ecosystems and reserving more of these small, nutritious fish for human consumption."The annual catch of wild fish has been static for almost 40 years, but over the same period the production from aquaculture has grown enormously," said Richard Cottrell, lead author of a paper that appears in the journal Approximately 16 million of the 29 million tonnes of forage fish -- such as herrings, sardines and anchovies -- caught globally each year are currently used for aquaculture feed. To meet the growing demand for fish in a sustainable manner, other types of fish feed must be used, the researchers said."We looked at a range of scenarios to predict future aquaculture production and, depending on consumer preferences, we found growth between 37-98% is likely," said Cottrell, a postdoctoral scholar at UCSB's National Center for Ecological Analysis & Synthesis (NCEAS), who conducted this work at the University of Tasmania.Fortunately, nutritional sources exist that could ease the growing demand for forage fish. Based on microalgae, insect protein and oils, these novel feeds could, in many cases, at least partially substitute fishmeal and oil in the feeds of many species without negative impacts on feed efficiency or omega-3 profiles."Previous work has identified that species such as carps and tilapias respond well, although others such as salmon are still more dependent on fish-based feeds to maintain growth and support metabolism," said Cottrell, who with his colleagues analyzed results from 264 scientific studies of farmed fish feeding experiments. As the nutrition and the manufacturing technologies improve for these novel feeds, they could allow for substantial reductions in the demand for wild-caught fishmeal in the future, he added."Even limited adoption of novel fish feeds could help to ensure that this growth (in aquaculture production) is achieved sustainably," Cottrell said, "which will be increasingly important for food security as the global population continues to rise."As we lean more on ocean-based food, the practices in place for producing it must come under scrutiny, and be improved where possible, according to UCSB marine ecologist and co-author Ben Halpern, director of NCEAS."Sorting out these questions about feed limitations and opportunities is nothing short of essential for the sector, and ultimately the planet," he said. " Without sustainable feed alternatives, we will not be able to sustainably feed humanity in the future."This study is one of several examinations of the potential for novel feed ingredients to replace wild caught forage fish in aquaculture."Our future research will continue to look at the wider consequences and trade-offs of shifting toward novel feed ingredients, including assessing the impacts on both marine and terrestrial environments, as well as balancing these with social and economic outcomes," said University of Tasmania associate professor and study co-author Julia Blanchard.Research in this study was conducted also by Halley E. Froehlich at UCSB and Marc Metian at the International Atomic Agency in Monaco.
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Agriculture & Food
| 2,020 |
May 20, 2020
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https://www.sciencedaily.com/releases/2020/05/200520125004.htm
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'Bee' thankful for the evolution of pollen
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Have pollen. Must travel.
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Over 80% of the world's flowering plants must reproduce in order to produce new flowers, according to the U.S. Forest Service. This process involves the transfer of pollen between plants by wind, water or insects called pollinators -- including bumblebees.In a new study, researchers at the University of Missouri discovered spiny pollen -- from a native wild dandelion species in the southern Rocky Mountains -- has evolved to attach to traveling bumblebees. Using a highly detailed electron scanning microscope, the research team could observe the microscopic surface of the spiny pollen, which otherwise looks like yellow dust to the naked eye."We observed this native pollen from the Rockies has optimally spaced spines that allow it to easily attach to a pollinator, such as a bumblebee," said Austin Lynn, a recent graduate with a doctorate in biology from the Division of Biological Sciences in the College of Arts and Science. "When we compared that with the average lawn dandelion, which does not need pollen to reproduce, we saw that the pollen on the lawn dandelion has a shorter distance between these spines, making it harder to attach to traveling pollinators. Therefore, we show this wild dandelion pollen has evolved over many generations to create an optimal shape for attaching to pollinators."Previous studies have examined spiny pollen, but this is one of the first studies focusing on the pollen's spines. Lynn, the lead researcher on the study, said the researchers were also able to refute a competing idea that spiny pollen serves as a defensive mechanism to protect the pollen from being eaten."The spiny pollen actually acts like Velcro," Lynn said. "So, when bees are harvesting pollen for food, this pollen is sticking to their hair. It's a great example of mutualism where the plant needs the pollinator to reproduce and the pollinator needs the plant for its food."The researchers plan to study how a bumblebee's hairs contribute to this process.
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Agriculture & Food
| 2,020 |
May 20, 2020
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https://www.sciencedaily.com/releases/2020/05/200520124952.htm
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Should tomatoes go in the fridge?
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There is much debate about the correct storage of tomatoes. There are two main options available to consumers: storage in the refrigerator or at room temperature. A research team from the University of Göttingen has now investigated whether there are differences in the flavour of ripe tomatoes depending on how they are stored and taking into account the chain of harvesting from farm to fork. No perceptible difference was found: the variety of tomato is much more important. The results have been published in the journal
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How does the flavour change when ripe, picked tomatoes go through a commercial post-harvest chain and are then stored either in the refrigerator (7 degrees Celsius) or at room temperature (20 degrees Celsius)? Researchers from the Division of Quality of Plant Products at the University of Göttingen analysed flavour-related attributes in new tomato strains drawing on the expertise of a "sensory panel." The sensory panel consisted of experienced and trained assessors who use their senses to perceive and evaluate the sensory properties of products. Among other attributes, this panel examined the discernible sweetness, acidity and juiciness of tomatoes. No significant differences in flavour were found between the two storage options when the entire post-harvest chain is taken into account."It is the variety of tomato in particular that has an important influence on the flavour. Therefore, the development of new varieties with an appealing flavour can be a step towards improving the flavour quality of tomatoes," says Larissa Kanski, lead author of the study. "The shorter the storage period, the better it is for the flavour and related attributes. However, we were able to show that, taking into account the entire post-harvest chain, short-term storage of ripe tomatoes in the refrigerator did not affect the flavour," reports Head of Division Professor Elke Pawelzik.
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Agriculture & Food
| 2,020 |
May 20, 2020
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https://www.sciencedaily.com/releases/2020/05/200520124935.htm
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The future is knocking: Global food production to be transformed using new technology
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The world's growing population and increasing human welfare will necessitate a 30-70% increase in food production over the next three decades. At the same time, the huge quantities of food needed must be produced in such a way that protects the environment and is resistant to climate change. If we are to succeed, it will require a complete overhaul of the way we produce food. Researchers from the University of Copenhagen, among others, have now created an overview of solutions that include a number of new technologies that can collectively address this global challenge. The results is published in
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"Unfortunately, if we are to meet the growing demand for food in the years ahead, optimising our current methods of production will be insufficient. They just won't do. A radical change is needed," states Svend Christensen, a professor and the Head of Department at the University of Copenhagen's Department of Plant and Environmental Sciences.He continues: "We have identified 75 new technologies which, combined, can transform the entire food chain -- from production and processing, to consumption and waste management -- to meet the demands of the future for significantly greater food production, that protects the environment and while being resilient to climate change."Together with an array of leading researchers from the 'Commonwealth Scientific and Industrial Research Organization' and the CGIAR Research Program on Climate Change, Agriculture and Food Security, Svend Christensen has identified a number of new and upcoming technologies that together, and each with their own approach, will be able to solve this global challenge for society. Most of these technologies are fully developed, while others are just a few steps away.Some of the more well-known technologies include artificial intelligence, robotics, genetic engineering, micro-algae production and vertical farming. Others include nitrogen-fixating cereals that do not require artificial fertilizers, biodegradable polymers and the breeding of insects for animal feed and foodstuffs.While each of these technologies are distinguished by their ability to reduce the climate footprint, there are tradeoffs that public authorities and decision makers must take a stand on. Among other things, the researchers cite the use of GMOs, as well as varying levels of access to new technologies from country to country."There is no doubt that this will require the support of, and large investments from, politicians, so that technologies and know-how are available in as many countries as possible. At the same time, there is a need to test and adapt these technologies in order for them to be used across the food chain, from farm to fork. This requires considerable investment and an acceptance of some of the technologies that need to be developed and adapted over many years. But this is the way forward if we are to solve this enormous challenge," says Svend Christensen.Some of the new technologies may seem controversial to consumers. Therefore -- in terms of generating public support and acceptance -- transparency, clear information and open dialogue will be necessary so that consumers can become comfortable with the new ways of producing food.
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Agriculture & Food
| 2,020 |
May 19, 2020
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https://www.sciencedaily.com/releases/2020/05/200519140405.htm
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Combined production of fish and vegetables can be profitable
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When it comes to future food production, the combined farming of fish and vegetables through aquaponics is currently a hotly debated topic. But how realistic is the idea? Publicly available data and analysis on the economic feasibility of professional aquaponics are at present very limited. Researchers from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) have just published an extensive profitability analysis of a facility that already produces fish and vegetables on a large scale. The result: aquaponics may have both environmental and cost benefits -- if produced according to good agricultural practice and under suitable conditions.
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The subject of analysis was the aquaponic system of the "Mueritzfischer," located in Waren (Mueritz). This 540 square metre facility produces fish and vegetables in a combined recirculating system. The aquaponic system was built within "INAPRO," an EU-funded project led by IGB.The researchers carried out extensive analysis based on real one-year production data. Although the aquaponic system was not profitable at the research stage, the very extensive and valuable set of data it produced enabled the researchers to develop two scenarios for production practice. One scenario showed that the aquaponics approach is profitable if facilities are sufficiently large. On the basis of this scenario, the scientists developed a model case with defined economic key indicators, enabling them to calculate the figures for different sized facilities."It is a good thing that there is a social, political and economic interest in aquaponics as a future technology. The aim of our study is to offer a research-based contribution to this debate, pointing out the opportunities and the challenges involved. This is one of the reasons why we decided to publish our findings cost-free, in open access format," explained Professor Werner Kloas, leader of the project.According to the IGB researchers, the main obstacles for commercial aquaponics are the high investment costs and, especially in Germany, the high operating costs such as for fish feed, labour and energy. They also state that undertakings must have the necessary expertise in both aquaculture and horticulture. Furthermore, the margin reportedly depends to a considerable extent on the market environment and the production risks, which are very difficult to forecast in some cases.The lead author of the study, Goesta Baganz, sees great potential in the system, despite the risks. Citing the example of urban spaces, he stated: "The already profitable model case would cover an overall space of about 2,000 square metres. This would mean that professional aquaponics would also be possible in urban and peri-urban areas, where space is scarce and often relatively expensive. If, therefore, urban aquaponics can make a profit on such a scale, there is even greater opportunity for local food production, which is becoming increasingly important throughout the world as urbanisation progresses.""Considering current problems like climate change, population growth, urbanisation as well as overexploitation and pollution of natural resources, global food production is the largest pressure caused by humans on Earth, threatening ecosystems and the stability of societies. Consequently, one of the key societal goals is to achieve eco-friendly, efficient food production," explained Werner Kloas, putting aquaponics research into the global context.How IGB aquaponics -- known also as "Tomatofish" -- works:A wide range of aquaponics approaches exist, many of which originated from amateur settings. The approach developed by IGB researchers is based on two recirculating systems in which fish and plants are produced in separate units. Smart software and sensors continuously take measurements and interconnect the two cycles, whenever needed, to make optimum use of synergies, whilst still creating the best growth conditions for both units.
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Agriculture & Food
| 2,020 |
May 15, 2020
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https://www.sciencedaily.com/releases/2020/05/200515115646.htm
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Global cooling event 4,200 years ago spurred rice's evolution, spread across Asia
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A major global cooling event that occurred 4,200 years ago may have led to the evolution of new rice varieties and the spread of rice into both northern and southern Asia, an international team of researchers has found.
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Their study, published in Rice is one of the most important crops worldwide, a staple for more than half of the global population. It was first cultivated 9,000 years ago in the Yangtze Valley in China and later spread across East, Southeast, and South Asia, followed by the Middle East, Africa, Europe, and the Americas. In the process, rice evolved and adapted to different environments, but little is known about the routes, timing, and environmental forces involved in this spread.In their study, the researchers reconstructed the historical movement of rice across Asia using whole-genome sequences of more than 1,400 varieties of rice -- including varieties of japonica and indica, two main subspecies of Asian rice -- coupled with geography, archaeology, and historical climate data.For the first 4,000 years of its history, farming rice was largely confined to China, and japonica was the subspecies grown. Then, a global cooling event 4,200 years ago -- also known as the 4.2k event, which is thought to have had widespread consequences, including the collapse of civilizations from Mesopotamia to China -- coincided with japonica rice diversifying into temperate and tropical varieties. The newly evolved temperate varieties spread in northern China, Korea and Japan, while the tropical varieties and spread to Southeast Asia."This abrupt climate change forced plants, including crops, to adapt," said Rafal M. Gutaker, a postdoctoral associate at the NYU Center for Genomics and Systems Biology and the study's lead author. "Our genomic data, as well as paleoclimate modeling by our collaborators, show that the cooling event occurred at the same time as the rise of temperate japonica, which grows in milder regions. This cooling event also may have led to the migration of rice agriculture and farmer communities into Southeast Asia.""These findings were then backed up by data from archaeological rice remains excavated in Asia, which also showed that after the 4.2k event, tropical rice migrated south while rice also adapted to northern latitudes as temperate varieties," said Michael D. Purugganan, the Silver Professor of Biology at NYU, who led the study.After the global cooling event, tropical japonica rice continued to diversify. It reached islands in Southeast Asia about 2,500 years ago, likely due to extensive trade networks and the movement of goods and peoples in the region -- a finding also supported by archeological data.The spread of indica rice was more recent and more complicated; after originating in India's lower Ganges Valley roughly 4,000 years ago, the researchers traced its migration from India into China approximately 2,000 years ago.While the researchers had thought that rainfall and water would be the most limiting environmental factor in rice diversity, they found temperature to be the key factor instead. Their analyses revealed that heat accumulation and temperature were very strongly associated with the genomic differences between tropical and temperate japonica rice varieties."This study illustrates the value of multidisciplinary research. Our genomic data gave us a model for where and when rice spread to different parts of Asia, archaeology told us when and where rice showed up at various places, and the environmental and climate modeling gave us the ecological context," said Purugganan. "Together, this approach allows us to write a first draft of the story of how rice dispersed across Asia."Understanding the spread of rice and the related environmental pressures could also help scientists develop new varieties that meet future environmental challenges, such as climate change and drought -- which could help address looming food security issues."Armed with knowledge of the pattern of rice dispersal and environmental factors that influenced its migration, we can examine the evolutionary adaptations of rice as it spread to new environments, which could allow us to identify traits and genes to help future breeding efforts," said Gutaker.
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Agriculture & Food
| 2,020 |
May 15, 2020
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https://www.sciencedaily.com/releases/2020/05/200515103923.htm
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Innovative virus research may save wheat and other crops
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UC Riverside scientists have solved a 20-year-old genetics puzzle that could result in ways to protect wheat, barley, and other crops from a devastating infection.
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Ayala Rao, professor of plant pathology and microbiology, has been studying Brome Mosaic virus for decades. Unlike some viruses, the genetic material of this virus is divided into three particles that until now were impossible to tell apart."Without a more definitive picture of the differences between these particles, we couldn't fully understand how they work together to initiate an infection that destroys food crops," Rao said. "Our approach to this problem has brought an important part of this picture into very clear focus."A paper describing the work Rao's team did to differentiate these particles was recently published in the Inside each of the particles is a strand of RNA, the genetic material that controls the production of proteins. The proteins perform different tasks, some of which cause stunted growth, lesions, and ultimately death of infected host plants.Two decades ago, scientists used the average of all three particles to create a basic description of their structure. In order to differentiate them, Rao first needed to separate them, and get them into their most pure form.Using a genetic engineering technique, Rao's team disabled the pathogenic aspects of the virus and infused the viral genes with a host plant."This bacterium inserts its genome into the plant's cells, similar to the way HIV inserts itself into human cells," Rao said. "We were then able to isolate the viral particles in the plants and determine their structure using electron microscopes and computer-based technology."Now that one of the particles is fully mapped, it's clear the first two particles are more stable than the third."Once we alter the stability, we can manipulate how RNA gets released into the plants," Rao said. "We can make the third particle more stable, so it doesn't release RNA and the infection gets delayed."This work was made possible by a grant from the University of California Multicampus Research Program and Initiatives. Professors Wiliam Gelbart and Hong Zhou of UCLA, as well as graduate students Antara Chakravarthy of UCR and Christian Beren of UCLA, made significant contributions to this project.Moving forward, Rao is hoping to bring the other two viral particles into sharper focus with the expertise of scientists at UCLA and UC San Diego.Brome Mosaic virus primarily affects grasses such as wheat and barley, and occasionally affects soybeans as well. According to Rao, it is nearly identical to Cucumber Mosaic virus, which infects cucumbers as well as tomatoes and other crops that are important to California agriculture.Not only could this research lead to the protection of multiple kinds of crops, it could advance the understanding of any virus."It is much easier to work with plant viruses because they're easier and less expensive to grow and isolate," Rao said. "But what we learn about the principles of replication are applicable to human and animal viruses too."
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Agriculture & Food
| 2,020 |
May 14, 2020
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https://www.sciencedaily.com/releases/2020/05/200514164234.htm
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Saving livestock by thinking like a predator
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For predators like wolves, cougars and snow leopards, a cow or sheep out to pasture may make for an easy and tasty meal. But when wild animals eat livestock, farmers face the traumatic loss of food or income, frequently sparking lethal conflicts between humans and their carnivorous neighbors.
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Humans have struggled to reduce the loss of livestock to carnivores for thousands of years, and yet, solutions remain elusive. According to a new study led by researchers at the University of California, Berkeley, solving this ancient puzzle requires going back to Ecology 101.Effectively reducing encounters between domestic prey and wild predators, the researchers argue, requires knowing the principles governing the ecological interactions among these players and their surrounding landscape. Simply put, getting in the mind of predators -- considering the ecology of how they hunt, how their prey behaves and how they interact with the landscape around them -- will help farmers and wildlife managers target interventions to discourage wild carnivores from preying on valuable livestock."There is no 'one-size-fits-all' solution for livestock predation, because the variables at play change, depending on the stakeholders, the landscape and the carnivores and livestock involved -- as well the scale and cost of management tools," said Christine Wilkinson, a graduate student in environmental science, policy and management at UC Berkeley and lead author on the study, which appeared this week in the journal In addition to lethal means of warding off potential predators, like poisoning or hunting, a variety of nonlethal deterrents are available. Guardian dogs, lights, electric fencing or bright-colored flags can all keep carnivores at bay while preserving the local ecology. Other strategies, like regularly moving livestock to different pastures or keeping them inside an enclosure at night, can make it harder for carnivores to locate and hunt them.But the same techniques that prevent wolves from eating sheep in the rocky valleys of Idaho may not be as effective at preventing snow leopards from killing livestock in the high elevations of the Himalayas. Instead of focusing on the overall effectiveness of any one technique, the authors urge wildlife managers to approach the problem by considering a framework that includes the carnivore ecology, the livestock ecology and how the two species interact with the landscape around them."By knowing the full ecological story, we can tinker with the tools in our management toolkit to keep both predators and livestock safe," said Defenders of Wildlife senior scientist and co-author Jennie Miller.For instance, wolves are known to be afraid of strings of red flags called fladry, and using fladry around a pasture might be a cost-effective method for keeping the predators away from sheep. But considering other aspects of the ecology, such as where the pastures are located, or where the sheep are kept at night, could yield even better results, depending on context.These strategic combinations of deterrents have successfully kept predators at bay in a variety of settings, the paper points out. The authors highlight three case studies from around the world, demonstrating the success that can occur when ecology is the foundation of targeted interventions, and the failure that can occur when it is ignored.The study's framework provides guidance for livestock managers to consider their management techniques as a component of livestock ecology. "Livestock have, in some sense, been bred to be an easy target for carnivores," Wilkinson said. "Humans have to recreate the defenses that we bred away."The next step for the researchers is applying this framework to provide livestock managers with concrete tools to mitigate conflict as part of a larger, collaborative research and outreach effort based in the Brashares Group at UC Berkeley.
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Agriculture & Food
| 2,020 |
May 14, 2020
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https://www.sciencedaily.com/releases/2020/05/200514143558.htm
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Multiscale crop modeling effort required to assess climate change adaptation
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Crop modeling is essential for understanding how to secure the food supply as the planet adapts to climate change. Many current crop models focus on simulating crop growth and yield at the field scale, but lack genetic and physiological data, which may hamper accurate production and environmental impact assessment at larger scales.
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In a new paper published in the journal Many crop models focus on understanding how plant characteristics such as leaf size play into the crop yield at the field scale, the researchers said. "Modeling at this scale is critical, but we would like to incorporate information from gene-to-cell and regional-to-global scale data into our modeling framework," said Bin Peng, a University of Illinois at Urbana-Champaign postdoctoral researcher and co-lead author.The study identifies components that could help generate a more informative modeling framework. "Multiscale modeling is the key to linking the design of climate change adaptation strategies for crop and field management with a large-scale assessment of adaptation impact on crop production, environment, climate and economy," Peng said.The study calls for a better representation of the physiological responses of crops to climate and environmental stressors -- like drought, extreme rainfall and ozone damage. "Many physiological processes would be important to simulate the crop growth under stressed conditions accurately," Peng said. Examples include water moving from soil to plant to atmosphere driven by canopy energy balance, he said."We should also include a better representation of crop management," Peng said. "That would be extremely important for assessing both crop production and environmental sustainability, as well as their tradeoffs."The researchers said there are opportunities to close a variety of data gaps, as well. "Integration of remote-sensing data, such as the work performed in our lab, will be extremely valuable for reducing data gaps and uncertainties," said natural resources and environmental sciences professor and project investigator Kaiyu Guan. "One of the advantages of remote sensing is its vast spatial coverage -- we can use remote sensing to constrain crop models over every field on the planet."The authors also propose a model-data integration pathway forward. "Doing the right simulation of crop responses to climate change factors is critically important," Guan said. "The most challenging part is whether crop models can capture those emergent relationships, which can be derived from empirical observations.""No single scientist or research lab can produce these models on their own," said study co-author and plant biology professor Amy Marshall-Colón. "This type of effort will require patience and collaboration across many disciplines."
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Agriculture & Food
| 2,020 |
May 14, 2020
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https://www.sciencedaily.com/releases/2020/05/200514131737.htm
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Cahokia's rise parallels onset of corn agriculture
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Corn cultivation spread from Mesoamerica to what is now the American Southwest by about 4000 B.C., but how and when the crop made it to other parts of North America is still a subject of debate. In a new study, scientists report that corn was not grown in the ancient metropolis of Cahokia until sometime between A.D. 900 and 1000, a relatively late date that corresponds to the start of the city's rapid expansion.
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The findings are published in the journal The research team determined the age of charred corn kernels found in homes, shrines and other archaeological contexts in and around Cahokia. The researchers also looked at carbon isotopes in the teeth and bones of 108 humans and 15 dogs buried in the vicinity.Carbon-isotope ratios differ among food sources, with isotope ratios of corn being significantly higher than those of almost all other native plant species in the region. By analyzing the ratio of carbon 12 to carbon 13 in teeth and bones, the team determined the relative proportion of different types of foods the people of Cahokia ate in different time periods.The corn remnants and isotope analyses revealed that corn consumption began in Cahokia between 900 and 1000. This was just before the city grew into a major metropolis."There's been an idea that corn came to the central Mississippi River valley at about the time of Christ, and the evolution of maize in this part of the world was really, really slow," said retired state archaeologist Thomas Emerson, who led the study. "But this Cahokia data is saying that no, actually, corn arrived here very late. And in fact, corn may be the foundation of the city."The research team included Illinois State Archaeological Survey archaeobotanist Mary Simon; bioarchaeologist Kristin Hedman; radiocarbon dating analyst Matthew Fort; and former graduate student Kelsey Witt, now a postdoctoral researcher at Brown University.Beginning in about 1050, Cahokia grew from "a little village of a few hundred people to part of a city with 5,000 to 10,000 people in an archaeological instant," Emerson said. The population eventually expanded to at least 40,000. This early experiment in urban living was short-lived, however. By 1350, after a period of drought and civil strife, most of the city's population had dispersed.Scientists who theorize that corn came to the central Mississippi River valley early in the first millennium A.D. are overlooking the fact that the plant had to adapt to a completely different light and temperature regime before it could be cultivated in the higher latitudes, said Simon, who conducted an exhaustive analysis of corn kernels found at Cahokia and elsewhere in the Midwest."Corn was originally cultivated in Mesoamerica," she said. "Its flowering time and production time are controlled by the amount of sunlight it gets. When it got up into this region, its flowering was no longer corresponding to the available daylight. If you planted it in the spring, it wouldn't even start to flower until August, and winter would set in before you could harvest your crop."The plant had to evolve to survive in this northerly climate, Simon said."It was probably only marginally adapted to high latitudes in what is now the southwestern United States by 0 A.D.," she said. "So, the potential for successful cultivation in the Midwest at this early date is highly problematic."When they analyzed the carbon isotopes in the teeth and bones of 108 individuals buried in Cahokia between 600 and 1400, researchers saw a signature consistent with corn consumption beginning abruptly between 950 and 1000, Hedman said. The data from dogs buried at and near Cahokia also corresponded to this timeline."That's where you see this big jump in the appearance of corn in the diet," Hedman said. "This correlates very closely with what Mary Simon is finding with the dates on the maize.""Between 900 and 1000 is also when you start to see a real shift in the culture of Cahokia," Emerson said. "This was the beginning of mound construction. There was a massive growth of population and a dramatic shift in ideology with the appearance of fertility iconography."Artifacts uncovered from Cahokia include flint-clay figurines of women engaged in agricultural activities and vessels marked with symbols of water and fertility. Some of the items depict crops such as sunflowers and squash that predated the arrival of corn."It wasn't like the Cahokians didn't already have an agricultural base when corn arrived on the scene," Simon said. "They were preadapted to the whole idea of cultivation."The absence of corn iconography in artifacts from the city reflects corn's status as a relative newcomer to the region at the time Cahokia first flourished, Emerson said.
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Agriculture & Food
| 2,020 |
May 14, 2020
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https://www.sciencedaily.com/releases/2020/05/200514092641.htm
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Oyster farming and shorebirds likely can coexist
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Oyster farming as currently practiced along the Delaware Bayshore does not significantly impact four shorebirds, including the federally threatened red knot, which migrates thousands of miles from Chile annually, according to a Rutgers-led study.
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The findings, published in the journal "Our research team represents a solid collaboration between aquaculture research scientists and conservation biologists, and we've produced scientifically robust and defensible results that will directly inform management of intertidal oysterculture along Delaware Bay and beyond," said lead author Brooke Maslo, an assistant professor and extension specialist in the Department of Ecology, Evolution, and Natural Resources in the School of Environmental and Biological Sciences at Rutgers University-New Brunswick.Aquaculture is a burgeoning industry along the Delaware Bayshore, infusing millions of dollars into local economies annually, and the production of oysters within the intertidal flats on Delaware Bay has grown in the last decade.Although a relatively small endeavor now, rising public interest in boutique oysters for the half-shell market (known as the Oyster Renaissance) and the "low-tech" nature of oyster tending make oyster farming an attractive investment for small-business entrepreneurs."Oyster farming has many ecological benefits and is widely recognized as one of the most ecologically sustainable forms of food production," said co-author David Bushek, a professor and director of Rutgers' Haskin Shellfish Research Laboratory in Port Norris, New Jersey. "Farmers appreciate the ecology around them as they depend on it to produce their crop. The idea that oyster farming might be negatively impacting a threatened species concerns them deeply, so they've voluntarily taken on many precautionary measures. They'd like to know which of these measures help and which don't as they all inhibit their ability to operate efficiently."Delaware Bay is a critical stopover area for the red knot, a reddish, robin-sized sandpiper. Every spring, the species feasts on horseshoe crab eggs after journeying from wintering grounds at the southern tip of South America. Red knots then fly to breeding grounds in the Canadian Arctic.Researchers assessed the impact of oyster aquaculture along the Delaware Bay on red knots and three other migratory birds of conservation concern: ruddy turnstones, semipalmated sandpipers and sanderlings. The scientists found that oyster tending reduced the probability of shorebird presence by 1 percent to 7 percent, while untended aquaculture structures had no detectable impact.The study showed foraging rates were mostly influenced by environmental conditions, especially the presence of gulls or other shorebirds. None of the four bird species of concern substantially altered their foraging behavior due to the presence of tended or untended oyster aquaculture.Next steps include investigating how oyster aquaculture may influence interactions between red knots and their main food source, horseshoe crab eggs, as well as examining how the expansion of oyster aquaculture along the Delaware Bay may affect the availability of foraging habitat at this globally important stopover site.
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Agriculture & Food
| 2,020 |
May 12, 2020
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https://www.sciencedaily.com/releases/2020/05/200512205552.htm
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Moths have a secret but vital role as pollinators in the night
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Moths are important pollen transporters in English farmland and might play a role in supporting crop yields, according to a new UCL study.
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The research, published in The team found that moths transport pollen from a high number of plants also visited by bees, butterflies and hoverflies, but also interacted with plants not commonly visited by these insects.The study also shows that pollen transport occurs most frequently on the moth's ventral thorax (chest), rather than on the proboscis (tongue), allowing it to be easily transferred to other plants.Lead author of the study, Dr Richard Walton (UCL Geography) said: "Nocturnal moths have an important but overlooked ecological role. They complement the work of daytime pollinators, helping to keep plant populations diverse and abundant. They also provide natural biodiversity back-up, and without them many more plant species and animals, such as birds and bats that rely on them for food, would be at risk."Previous studies of pollen transport among settling moths have focused on their proboscis. However, settling moths sit on the flower while feeding, with their often distinctly hairy bodies touching the flower's reproductive organs. This happy accident helps pollen to be easily transported during subsequent flower visits."This pivotal study comes at the time as moth populations are experiencing steep declines across the globe, with worrying implications that we may be losing critical pollination services at a time when we are barely beginning to understand them.Dr Jan Axmacher (UCL Geography) said: "In recent decades, there has been a lot of science focus on solitary and social bees driven by concerns about their dramatic decline and the strong negative effect this has had on insect-pollinated crop yields."In contrast, nocturnal settling moths -- which have many more species than bees -- have been neglected by pollination research. Our study highlights an urgent need for them to be included in future agricultural management and conservation strategies to help stem declines, and for more research to understand their unique and vital role as pollinators, including their currently unknown role in crop pollination."The study was conducted during the growing seasons (March-October) of 2016 and 2017 at the margins of nine ponds, located within agricultural fields in Norfolk, eastern England (UK).Nocturnal moth communities and daytime pollinators were surveyed once a month to see which plants they visited and how frequently.Of the 838 moths swabbed, 381 moths (45.5%) were found to transport pollen. In total pollen from 47 different plant species was detected, including at least 7 rarely visited by bees, hoverflies and butterflies. 57% of the pollen transported was found on the ventral thorax of the moths.In comparison, daytime pollinators, a network of 632 bees, wasps, hoverflies and butterflies, visited 45 plant species, while 1,548 social bees visited 46 plant species.Dr Walton (UCL Geography) concluded: "While bumblebees and honeybees are known to be super pollinators they also preferentially target the most prolific nectar and pollen sources."Moths may appear to be less effective pollinators by comparison, but their high diversity and abundance may make them critical to pollination in ways that we still need to understand. Our research sheds light on a little known world of nocturnal plant-insect interactions that might be vital to the look and smell of our precious countryside and to the crops that we grow."The research was funded by the Norfolk Biodiversity Information Service and the Norfolk-based farming charity The Clan Trust.
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Agriculture & Food
| 2,020 |
May 12, 2020
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https://www.sciencedaily.com/releases/2020/05/200512151946.htm
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New software supports decision-making for breeding
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A team of researchers at the University of Göttingen has developed an innovative software program for the simulation of breeding programmes. The "Modular Breeding Program Simulator" (MoBPS) enables the simulation of highly complex breeding programmes in animal and plant breeding and is designed to assist breeders in their everyday decisions. Furthermore, the program is intended to be a cornerstone for further studies in breeding research in Göttingen. In addition to purely economic criteria in breeding, the research team is striving for goals such as sustainability, conservation of genetic diversity and improved animal welfare. The software was presented in the journal G3 Genes, Genomes, Genetics.
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"By simulating breeding programmes, conclusions can be drawn about genetic improvements," says Torsten Pook from the Centre for Integrated Breeding Research (Cibreed) at the University of Göttingen. "In fact, potentially problematic issues such as inbreeding or adverse effects on the health of the animals can also be identified at an early stage." Pook is the main developer of MoBPS. The software offers opportunities to realistically model common processes in breeding such as selection, reproduction and data-collection (eg DNA information, trait observations). At the same time, it can simulate millions of matings of animals with certain features in just a few minutes."From the simulation of simple maize-breeding programmes, to increased consideration of bone stability in horse breeding, to the simulated development of red deer populations in Baden-Württemberg over the last 200 years, everything has been done," said Pook. The next goal of the research team is to develop an additional module for MoBPS that can automatically optimise breeding programmes with a large number of variables and under given constraints.
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Agriculture & Food
| 2,020 |
May 11, 2020
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https://www.sciencedaily.com/releases/2020/05/200511154854.htm
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How to boost plant biomass: Biologists uncover molecular link between nutrient availability, growth
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Plant scientists have long known that crop yield is proportional to the dose of nitrogen fertilizer, but the increased use of fertilizers is costly and harmful to the environment. Until now, the underlying mechanisms by which plants adjust their growth according to the nitrogen dose has been unknown -- a key finding that could help enhance plant growth and limit fertilizer use.
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In a new study published in the Taking a novel approach, the NYU researchers examined how increasing doses of nitrogen created changes in plants' genome-wide expression as a function of time. They then used mathematical models to investigate the rate of change of messenger RNA (mRNA) for thousands of genes within the genome to this experimental set up.The researchers discovered that the dynamics of mRNA responses to nitrogen dose were governed by simple principles of enzyme kinetics -- the rates of reactions catalyzed by enzymes -- first described by Michaelis-Menten in 1913. Indeed, the authors found that Michaelis-Menten kinetics could accurately model the rate of change in gene expression in 30 percent of nitrogen-dose responsive genes."According to the classic Michaelis-Menten kinetic model, changing enzyme abundance will impact the maximum rate of reaction possible. Because transcription factors establish the rates at which gene transcription from DNA into RNA takes place, they can be directly compared to the catalytic enzymes in the Michaelis-Menten model. This means that increasing the abundance of key transcription factors should be able to boost the rate of nitrogen-dose dependent gene expression and, as a consequence, the rate of plant growth," said Gloria Coruzzi, Carroll & Milton Petrie Professor in NYU's Department of Biology and Center for Genomics & Systems Biology, and the paper's senior author.The research team found that increasing the level of the transcription factor TGA1 accelerated the rates of nitrogen-dose responsive gene expression and the rate of plant growth. The plants that overexpressed TGA1 had increased growth rates in response to nitrogen, reaching a plant biomass three times greater than wild type plants."By modeling the transcriptome kinetics underlying nitrogen-dose sensing using a classic principle of Michaelis-Menten kinetics, we discovered a regulatory gene whose increased expression may boost crop growth within low-nitrogen soils," said Coruzzi. "Because TGA1 is conserved in plants, including crops such as rice, tomatoes, and wheat, our findings have implications for improving nitrogen use efficiency in crops, which can benefit agriculture and sustainability."In addition to Coruzzi, study authors include Joseph Swift and Viviana Araus of NYU, Jose Alvarez of Universidad Mayor in Chile, and Rodrigo Gutiérrez of Pontificia Universidad Católica de Chile. This work was supported by the Zegar Family Foundation, the Beachell-Borlaug International Scholarship, and the National Science Foundation (NSF-PGRP: IOS-1339362 and NSF-DBI-0445666).
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Agriculture & Food
| 2,020 |
May 11, 2020
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https://www.sciencedaily.com/releases/2020/05/200511154852.htm
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Bumble bee disease, reproduction shaped by flowering strip plants
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Flowering strips -- pollinator-friendly rows of plants that increase foraging habitat for bees -- can help offset pollinator decline but may also bring risks of higher pathogen infection rates for pollinators foraging in those strips.
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Researchers from North Carolina State University and the University of Massachusetts Amherst show that flowering strip plants generally benefitted bee colony reproduction by adding floral resources for common eastern bumble bees (Bombus impatiens). The results came with a tradeoff, however, as bumble bees exposed to certain plants showed higher rates of infection by a bee pathogen acquired on flowers -- The study showed that certain "high-infection" plants doubled Nonetheless, all bee colonies that foraged on flowering strips -- both low-infection and high-infection types -- showed increases in reproduction relative to bees that only had access to canola."We wanted to know the effects of flowering strip plant species on the health and reproduction of bumble bees," said Rebecca E. Irwin, professor of applied ecology at NC State and a co-author of a paper describing the research, published in The researchers used information gleaned from a previous study to split flowering strips into low- and high-infection portions. Low-infection plants included sunflower and thyme, while high-infection plants included swamp milkweed and purple loosestrife."In a prior study, we evaluated 15 plant species by putting the same amount of Researchers placed bees in tents with the crop plants and either high-infection flowering strips, low-infection flowering strips or no flowering strips."The bees were all infected with the same amount of pathogen and then allowed to forage, so the plants could increase or decrease infection," Adler said.Adler said the flowering-strip tradeoff -- more bee reproduction but higher pathogen infection rates -- may be acceptable."It depends on how critical food versus the pathogen is for pollinators," she said. "Crithidia is somewhat benign, but if these patterns hold for other pathogens like Nosema, a common honey bee disease, it may be more of a concern. Right now I would not recommend stopping our investment in flowering strips."The researchers hope to continue examining the effects of flowering strips on bee populations and health by including other bee species and pathogen types."I think we need a much more comprehensive program to evaluate how pollinator habitat characteristics affect pathogen spread to make informed choices," Adler said. "In the meantime, providing flowering resources in pollinator habitat is still the best path forward."
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Agriculture & Food
| 2,020 |
May 11, 2020
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https://www.sciencedaily.com/releases/2020/05/200511142114.htm
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Microalgae food for honey bees
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A microscopic algae ("microalgae") could provide a complete and sustainably sourced supplemental diet to boost the robustness of managed honey bees, according to research just published by Agricultural Research Service (ARS) scientists in the journal
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Poor nutrition in honey bees is often an underlying factor in colony losses because malnutrition amplifies the detrimental effects of parasites, pathogens, and pesticides. Habitat loss, decreases in flowering plant diversity and large tracts of crop monoculture (cultivation of a single crop over a large area) all can potentially contribute to lessening natural pollen sources, which provide bees essential nutrition.Now, research by ARS entomologists Vincent Ricigliano and Michael Simone-Finstrom has shown that the microalgae Arthrospira platensis (commonly called spirulina) has a nutritional profile that closely resembles pollen. Spirulina is a part of family of blue-green algae, which are single-celled organisms that exist individually or in chains or groups.Ricigliano and Simone-Finstrom found that spirulina is rich in essential amino acids and lipids required by bees, with levels matching those found in tested pollen samples.The two scientists are both with the ARS Honey Bee Breeding, Genetics, and Physiology Research Laboratory in Baton Rouge, Louisiana."Our work is a pioneering first look into the nutritional and functional properties of a single microalga and how well it corresponds to what is needed in a complete pollen substitute for the honey bee," explained Ricigliano.In addition to being rich in essential amino acids necessary for protein synthesis, immune function and colony growth in honey bees, spirulina also contains prebiotics that support the growth of healthy gut bacteria.Commercial beekeepers have become increasingly reliant on artificial pollen substitute diets to nourish colonies during periods of pollen scarcity as well as to bolster colony size before they fulfill pollination service contracts.Currently available commercial diets for bees usually incorporate a variety of ingredients such as soy, yeast, wheat, lentils and milk proteins in an effort to supply balanced nutrition. These artificial diets are sometimes deficient in essential macronutrients (proteins, lipids, prebiotic fibers), micronutrients (vitamins, minerals), or antioxidants."So the need to scientifically improve the efficacy of pollen substitutes can be considered vital to modern beekeeping and we need to think about how we can do it in a sustainable way," Ricigliano said.Microalgae can be sustainably grown on a large scale with a minimal amount of water and few chemical inputs. It can even be grown in places where soybeans and other crops cannot be grown."All it takes are shallow ponds, nutrient salts and sunlight to produce highly nutritious microalgae," said Ricigliano.Now, the researchers are testing the microalgae diet in a field setting to make sure the diet is attractive to bees and supports colony growth. The excellent nutrition profile of spirulina suggests that there are likely other microalgae that could serve honey bees well, Simone-Finstrom pointed out."We have also begun development of new microalgae strains to address other aspects of bee health, including targeted nutrition strategies," Ricigliano added
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Agriculture & Food
| 2,020 |
May 11, 2020
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https://www.sciencedaily.com/releases/2020/05/200511112611.htm
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Chemical evidence of dairying by hunter-gatherers in Lesotho in the first millennium AD
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After analysing organic residues from ancient pots, a team of scientists led by the University of Bristol has uncovered new evidence of dairying by hunter-gatherers in the landlocked South African country of Lesotho in the mid-late first millennium AD.
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The study on organic residue analysis from South African hunter-gatherer pots is being published today in Although these farmers appear to have been in contact with local lowland hunter-gatherer groups, it was long assumed that they had little or no direct contact with hunter-gatherers already occupying the mountainous regions of Lesotho, as they did not settle the region until the 19th century due to the unsuitability of the mountains for crop cultivation.Over the past several decades however, remains of domestic animal bones have been uncovered in several sites in the Maloti-Drakensberg Mountains in Lesotho in hunter-gatherer contexts dating to the 1st and 2nd millennia AD.At one site in particular -- Likoaeng -- domestic animal bones were found in association with an Early Iron Age potsherd and some fragments of iron. This discovery led to the suggestion that the hunter-gatherers occupying the site were following a 'hunters-with-sheep' mode of subsistence that incorporated the keeping of small numbers of livestock into what was otherwise a foraging economy and that they must have obtained these animals and objects through on-going contact with agricultural groups based on the coast.In the past five years however, several studies have sequenced DNA from supposed domestic animal bones from these highland sites, and instead found them to belong to wild species. This led to the suggestion that the presence of domestic animals in the highlands, and therefore the level of contact, had been overestimated, yet the zooarchaeologists involved stand by their original morphological assessment of the bones.Lead researcher, Helen Fewlass, now based at the Max Planck Institute for Evolutionary Anthropology (Leipzig) but who carried out the work as part of her master's project in the University of Bristol's Department of Anthropology and Archaeology, said: "We used organic residue analysis to investigate fats that become absorbed into the porous clay matrix of a pot during its use."We extracted and analysed lipid residues from pots from two hunter-gatherer sites with domestic livestock remains in the highlands of Lesotho, Likoaeng and Sehonghong, dating to the mid-late first millennium AD and compared them to lipids extracted from pots from a recent nearby agricultural settlement, Mokatlapoli."This allowed us to explore the subsistence practices of the hunter-gatherers occupying these sites to see if there was any evidence for their contact with farming groups."The team found that dairy residues were present in approximately a third of the hunter-gatherer pots. They directly radiocarbon dated a dairy residue from Likoaeng to AD 579-654 and another from Sehonghong to AD 885-990. The results confirm the presence of domestic animals at these sites in the 1st millennium AD.The team also observed patterning in the stable carbon isotopic values of fatty acids in the residues, which imply that different methods of animal husbandry were practised by the 1st millennium hunter-gatherer groups compared to the recent agricultural group occupying the same region.The stable carbon isotopic values of dairy residues from the agricultural site clearly reflect the introduction of crops such as maize and sorghum into the region in the late nineteenth century and the foddering of domestic animals upon them.As the hunter-gatherer groups must have learnt animal husbandry techniques, the results support the notion that hunter-gatherer groups in the highlands of Lesotho had on-going contact with farming communities in the lowlands, rather than just obtaining the animals through raids or long-distance exchange networks. Based on the direct date of the dairy residue from Likoaeng, contact must have been established within a few centuries of the arrival of agricultural groups in the coastal regions of South Africa.The results also have implications for the on-going debate about the molecular vs morphological assessment of the faunal remains. The results of the organic residue analysis support the osteoarchaeological evidence for the presence of domestic animals at Likoaeng and Sehonghong. However, as large amounts of milk can be generated from one domestic animal, the prevalence of dairy residues does not tell us how many domestic animals were present.Direct radiocarbon dating of domestic faunal remains in these contexts has been hampered by poor collagen preservation. The new method (published earlier this month in Nature) for direct dating of fats extracted from potsherds represents a new avenue for placing the arrival and presence of domestic animals in the area in a secure chronological context.Helen Fewlass added: "The presence of dairy fats in pots from Likoaeng and Sehonghong in highland Lesotho shows that hunter-gatherers in the mountains had adopted at least sporadic use of livestock from agricultural groups in South Africa not long after their arrival in the 1st millennium AD."Co-author, Dr Emmanuelle Casanova, from the University of Bristol's Organic Geochemistry Unit -- part of the School of Chemistry, added: "In addition to the identification of dairying practices we were able apply a brand-new dating method for pottery vessels to verify the antiquity of the dairy residues which perfectly fits with the age of the hunter-gatherer groups."This study represents the first analysis and direct radiocarbon dating of organic residues from pottery from south-eastern Africa. The high level of preservation found implies that the method has great potential for further applications in the region. This mountainous area of Lesotho has other hunter-gatherer sites containing pottery in contexts dating to the 1st and 2nd millennium AD so there is potential to expand this type of analysis to other sites in the region to understand whether this practise was relatively isolated or ubiquitous.
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Agriculture & Food
| 2,020 |
May 8, 2020
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https://www.sciencedaily.com/releases/2020/05/200508083547.htm
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How a molecular 'alarm' system in plants protects them from predators
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Some plants, like soybean, are known to possess an innate defense machinery that helps them develop resistance against insects trying to feed on them. However, exactly how these plants recognize signals from insects has been unknown until now. In a new study, scientists in Japan have uncovered the cellular pathway that helps these plants to sense danger signals and elicit a response, opening doors to a myriad of agricultural applications.
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In nature, every species must be equipped with a strategy to be able to survive in response to danger. Plants, too, have innate systems that are triggered in response to a particular threat, such as insects feeding on them. For example, some plants sense "herbivore-derived danger signals" (HDS), which are specific chemicals in oral secretions of insects. This activates a cascade of events in the plant's defense machinery, which leads to the plant developing "resistance" to (or "immunity" against) the predator. But despite decades of research, exactly how plants recognize these signals has remained a bit of a mystery.In a new study published in To begin with, the scientists focused on soybean RLK genes that were structurally and functionally similar to a RLK gene, which is known to trigger a danger response by recognizing "oligosaccharides" (small carbohydrate molecules) during pathogen attack. They speculated that owing to these similarities, soybean genes might also show a mechanism similar to that seen in pathogen resistance. They found 15 such genes through genetic analysis. Next, the scientists generated 15 types of Arabidopsis plants, each plant uniquely expressing only one of the 15 individual soy genes. When they tested these plants using oral secretions from the pest, they uncovered genes for two novel RLKs that showed a defense response specific to the oral secretions, called GmHAK1 and GmHAK2. These findings were unprecedented: the role of these RLKs in soybean HDS systems had never been revealed before. Moreover, when the scientists dug deeper into the mechanism of these regulatory factors in Arabidopsis, they found two proteins, a HAK homolog and PBL27 (which play a role in intracellular signaling), to be involved in this pathway. Accordingly, this confirmed what the scientists had initially expected―soybean and Arabidopsis possess similar mechanisms for "danger response."In agriculture, it is crucial to develop strategies for pest control in crop plants to avoid incurring losses. This study takes a massive step in this direction by uncovering an important cellular mechanism that triggers defense response in plants. Manipulating this innate cellular system may even help scientists to fuel the development of new agricultural products, potentially making life easier for farmers. Prof Arimura concludes, "It has been challenging to find new pest control methods that are effective and do not harm the ecosystem in any way. Our study offers a potential solution to this problem by uncovering the details of how certain plants develop resistance."
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Agriculture & Food
| 2,020 |
May 7, 2020
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https://www.sciencedaily.com/releases/2020/05/200507131327.htm
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Virgin birth has scientists buzzing
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In a study published today in
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"It is extremely exciting," said Professor Benjamin Oldroyd in the School of Life and Environmental Sciences. "Scientists have been looking for this gene for the last 30 years. Now that we know it's on chromosome 11, we have solved a mystery."Behavioural geneticist Professor Oldroyd said: "Sex is a weird way to reproduce and yet it is the most common form of reproduction for animals and plants on the planet. It's a major biological mystery why there is so much sex going on and it doesn't make evolutionary sense. Asexuality is a much more efficient way to reproduce, and every now and then we see a species revert to it."In the Cape honey bee, found in South Africa, the gene has allowed worker bees to lay eggs that only produce females instead of the normal males that other honey bees do. "Males are mostly useless," Professor Oldroyd said. "But Cape workers can become genetically reincarnated as a female queen and that prospect changes everything."But it also causes problems. "Instead of being a cooperative society, Cape honey bee colonies are riven with conflict because any worker can be genetically reincarnated as the next queen. When a colony loses its queen the workers fight and compete to be the mother of the next queen," Professor Oldroyd said.The ability to produce daughters asexually, known as "thelytokous parthenogenesis," is restricted to a single subspecies inhabiting the Cape region of South Africa, the Cape honey bee or Apis mellifera capensis.Several other traits distinguish the Cape honey bee from other honey bee subspecies. In particular, the ovaries of worker bees are larger and more readily activated and they are able to produce queen pheromones, allowing them to assert reproductive dominance in a colony.These traits also lead to a propensity for social parasitism, a behaviour where Cape bee workers invade foreign colonies, reproduce and persuade the host colony workers to feed their larvae. Every year in South Africa, 10,000 colonies of commercial beehives die because of the social parasite behaviour in Cape honey bees."This is a bee we must keep out of Australia," Professor Oldroyd said.The existence of Cape bees with these characters has been known for over a hundred years, but it is only recently, using modern genomic tools, that we have been able to understand the actual gene that gives rise to virgin birth."Further study of Cape bees could give us insight into two major evolutionary transitions: the origin of sex and the origin of animal societies," Professor Oldroyd said.Perhaps the most exciting prospect arising from this study is the possibility to understand how the gene actually works functionally. "If we could control a switch that allows animals to reproduce asexually, that would have important applications in agriculture, biotechnology and many other fields," Professor Oldroyd said. For instance, many pest ant species like fire ants are thelytokous, though unfortunately it seems to be a different gene to the one found in Capensis."
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Agriculture & Food
| 2,020 |
May 7, 2020
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https://www.sciencedaily.com/releases/2020/05/200507104446.htm
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Global trade in soy has major implications for climate
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The extent to which Brazilian soy production and trade contribute to climate change depends largely on the location where soybeans are grown. This is shown by a recent study conducted by the University of Bonn together with partners from Spain, Belgium and Sweden. In some municipalities, CO
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Global soy trade is a major source of greenhouse gas emissions for multiple reasons. The conversion of natural vegetation into arable land is probably the most important cause, since the latter generally binds considerably less COTo estimate the carbon footprint embodied in Brazil's soy exports, researchers used the Life Cycle Assessment (LCA) methodology. This allows quantifying the environmental footprint of a product, from its production until it is delivered to the importer. The researchers from the Institute for Food and Resource Economics (ILR) of the University of Bonn have performed this analysis for almost 90,000 supply chains that were identified in total soy exports from Brazil in the period 2010-2015. "Each of these 90,000 individual trade flows represents a specific combination of the producing municipality in Brazil, the location in which the soy was stored and pre-processed, the respective export and import ports, and, where applicable, the country where further processing takes place," explains the ILR researcher Dr Neus Escobar. "Put more simply, we have calculated the quantity of carbon dioxide released per tonne of soy exported through each of these supply chains."For this purpose, the researchers used a database developed at the Stockholm Environment Institute. It traces the trade routes of agricultural commodity exports from the production region to the importer in detail. "The database also contains spatially-explicit information on the deforestation associated with the soy cultivation in the production region," says Escobar. "We supplemented it with additional data, for instance, on means of transport involved in the corresponding export route, as well as their COThe greatest COThe researchers also investigated which countries generate particularly large quantities of greenhouse gas emissions by importing soy. First and foremost, the world's largest importer is China, however, the European Union does not fall far behind. "Although European countries imported considerably smaller amounts of soy, between 2010 and 2015, this came primarily from areas where sizeable deforestation took place," notes Escobar."Regional factors can have a significant influence on the environmental impacts embodied in global agricultural trade," explains the researcher. "Our study helps to shed light on such relationships." Policymakers urgently need such information: It can help to design low-carbon supply chains, for instance with improvements in the transport infrastructure or more effective forest conservation policies. Furthermore, it can also inform consumers about the environmental implications of high meat consumption, such as in many EU countries: A large proportion of the soy imported by Europe is used as animal feed.
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Agriculture & Food
| 2,020 |
May 7, 2020
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https://www.sciencedaily.com/releases/2020/05/200507102432.htm
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New technique delivers complete DNA sequences of chromosomes inherited from mother and father
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An international team of scientists led by the University of Adelaide's Davies Research Centre has shown that it is possible to disentangle the DNA sequences of the chromosomes inherited from the mother and the father, to create true diploid genomes from a single individual.
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In a report published in Although demonstrated in cattle, the approach is applicable to other species including humans.Dr Lloyd Low, from the University of Adelaide's School of Animal and Veterinary Science, says the technique, called trio binning, gives the true genome sequence of each chromosome in an individual.Obtaining a full genome from an organism that inherits half the chromosomes from the mother and the other half from the father is difficult due to the high similarity between the parental chromosomes."Back in 2018 we were able to demonstrate that with this method it was possible to identify large sections of the DNA from the parents. Now in 2020 we have used the same concept to create the sequence of full chromosomes," Lloyd said.Professor John Williams added: "Disentangling maternal and paternal genomes is very difficult, but we have now been able to do this and create the best genome assemblies available for any livestock, and arguably any species.""These high quality genome sequences will make it easier to more accurately study the genetics of cattle to improve production and welfare traits."Brahman and Angus cattle subspecies were domesticated separately thousands of years ago and have been subjected to very different selection pressures since then; pest and humid environments in the case of the Brahman cattle and beef production in Angus cattle. These different characteristics and histories are reflected in their genomes, which makes them ideal test subjects.Indian breeds such as Brahman cattle are better able to regulate body temperature and are routinely crossed with European breeds such as Angus to produce cattle that are better adapted to tropical climates.Considering the large differences in production and adaptation traits between taurine and indicine cattle, comparing the genomes helps us understand how the animals adapt to their environment, which is of substantial scientific and economic interest.Professor Stefan Hiendleder said high-quality genomes of both cattle subspecies were needed to decipher the differences between taurine and indicine cattle."This technology will ultimately lead to breeding cattle which are more productive in harsh environments and also better suited from an animal welfare perspective," he said."Comparison between the Brahman and Angus revealed an indicus-specific extra copy of fatty acid enzyme which may be important for the regulation of the metabolism related to heat tolerance."The research is a collaboration between the University of Adelaide Davies Research Centre, the US Department of Agriculture, and the National Institutes of Health.
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Agriculture & Food
| 2,020 |
May 5, 2020
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https://www.sciencedaily.com/releases/2020/05/200505121703.htm
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Plants pass on 'memory' of stress to some progeny, making them more resilient
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By manipulating the expression of one gene, geneticists can induce a form of "stress memory" in plants that is inherited by some progeny, giving them the potential for more vigorous, hardy and productive growth, according to Penn State researchers, who suggest the discovery has significant implications for plant breeding.
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And because the technique is epigenetic -- involving the expression of existing genes and not the introduction of new genetic material from another plant -- crops bred using this technology could sidestep controversy associated with genetically modified organisms and food."One gene, MSH1, gives us access to what is controlling a broad array of plant resiliency networks," said Sally Mackenzie, professor of plant science in the College of Agricultural Sciences and professor of biology in the Eberly College of Science. "When a plant experiences a stress such as drought or prolonged extreme heat, it has the ability to adjust quickly to its environment to become phenotypically 'plastic' -- or flexible."There are many ways to inactivate the MSH1 gene, researchers explain, and in this context they all work. In well-studied plant species, like Arabidopsis, tomato or rice, it is possible to identify mutations in the gene. In others, and for commercial testing, it is possible to design a transgene that uses "RNA interference" to specifically target MSH1 for gene silencing. Any method that silences MSH1 results in very similar outcomes, they report."When plants are modified epigenetically, they can modify many genes in as simple a manner as possible," Mackenzie pointed out. That includes adjusting the circadian clock -- detecting light and triggering growth and reproductive phases -- and modifying hormone responses to give them maximum flexibility, making them more resilient.Plants that "detect" stress after the MSH1 gene is silenced can adjust their growth and change root configuration, limit above-ground biomass, delay flowering time and alter their response to environmental stimuli. Those responses are "remembered," researchers reported, and passed in selective breeding through many generations."In our research, we show that this memory condition is heritable by progeny but occurs in only a proportion of the progeny -- so that there are memory and non-memory full siblings," said Mackenzie, the Lloyd and Dottie Huck Chair for Functional Genomics. "That results in definable gene expression changes that impact a plant's phenotypic 'plasticity.' We suggest that all plants have this capacity, and that the condition that we describe is likely to be an important part of how plants transmit memory of their environment to precondition progeny."By adjusting the epigenetic architecture of a plant, researchers were able to access its resiliency network, and see how genes are expressed quickly and broadly to adjust a plant's growth to adapt to the environment, noted Mackenzie, director of the Plant Institute at Penn State.The researchers identify pathways that enhance root growth and plant vigor -- increasing yield. They present their results today (May 5) in Researchers contend that plants can be "reprogrammed" epigenetically to express genes differently without altering genotype, which constitutes a non-traditional approach to breeding. Because they can now identify gene networks that appear to be targeted by this manipulation, researchers report that plants have mechanisms designed to address stress or alter growth, and these can be accessed.The researchers focused their efforts on the small flowering plant, Arabidopsis, or rockcress, a relative of cabbage and mustard in the Brassica family. It is one of the model organisms used for studying plant biology and the first plant to have its entire genome sequenced. Arabidopsis is useful for genetic experiments because of its short generation time and prolific seed production through self-pollination. Researchers grew five generations of Arabidopsis to study "memory" and "non-memory" plants.In follow-up research already underway in Mackenzie's lab, the researchers have suppressed MSH1 genes in tomato and soybean plants and grafting experiments have been field tested with excellent yield results. A large-scale experiment growing MSH1-modified canola is now in the works. This technology is part of a start-up company called EpiCrop Technologies Inc. that was co-founded on MSH1 technology and its utility in agriculture.The Bill and Melinda Gates Foundation, the National Science Foundation and the National Institutes of Health supported this work.
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Agriculture & Food
| 2,020 |
May 4, 2020
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https://www.sciencedaily.com/releases/2020/05/200504155200.htm
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Intensive farming increases risk of epidemics
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Overuse of antibiotics, high animal numbers and low genetic diversity caused by intensive farming techniques increase the likelihood of pathogens becoming a major public health risk, according to new research led by UK scientists.
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An international team of researchers led by the Universities of Bath and Sheffield, investigated the evolution of Campylobacter jejuni, a bacterium carried by cattle which is the leading cause of gastroenteritis in high income countries.Campylobacter facts:The researchers, publishing in the journal The authors of the study suggest that changes in cattle diet, anatomy and physiology triggered gene transfer between general and cattle-specific strains with significant gene gain and loss. This helped the bacterium to cross the species barrier and infect humans, triggering a major public health problem.Combine this with the increased movement of animals globally, intensive farming practices have provided the perfect environment in which to spread globally through trade networks.Professor Sam Sheppard from the Milner Centre for Evolution at the University of Bath, said: "There are an estimated 1.5 billion cattle on Earth, each producing around 30 kg of manure each day; if roughly 20 per cent of these are carrying Campylobacter, that amounts to a huge potential public health risk."Over the past few decades, there have been several viruses and pathogenic bacteria that have switched species from wild animals to humans: HIV started in monkeys; H5N1 came from birds; now Covid-19 is suspected to have come from bats."Our work shows that environmental change and increased contact with farm animals has caused bacterial infections to cross over to humans too."I think this is a wake-up call to be more responsible about farming methods, so we can reduce the risk of outbreaks of problematic pathogens in the future."Professor Dave Kelly from the Department of Molecular Biology and Biotechnology at the University of Sheffield said: "Human pathogens carried in animals are an increasing threat and our findings highlight how their adaptability can allow them to switch hosts and exploit intensive farming practices."The researchers hope that their study can help scientists predict potential problems in the future so they can be prevented before they turn into another epidemic.
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Agriculture & Food
| 2,020 |
May 4, 2020
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https://www.sciencedaily.com/releases/2020/05/200504150218.htm
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Warming Midwest conditions may result in corn, soybean production moving north
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If warming continues unabated in the Midwest, in 50 years we can expect the best conditions for corn and soybean production to have shifted from Iowa and Illinois to Minnesota and the Dakotas, according to Penn State researchers.
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Using machine learning -- a form of artificial intelligence that enables a computer system to learn from data -- the team considered more than three decades of county-level, crop-yield data from the U.S. Department of Agriculture's National Agricultural Statistics Service for 18 states in the central region of the United States. That area produces the majority of these crops.The researchers evaluated crop yields along with weather data. They considered fundamental climate variables to find yield predictors specific to each of the crop-growing phases. The study also analyzed the relationships between climate and corn, sorghum and soybean grain yield from 1980 to 2016."This kind of research was impossible before the era of big data we are living in now, and of course, it can be done only by using the powerful computing capacity that we can access at Penn State," said researcher Armen Kemanian, associate professor of production systems and modeling in the College of Agricultural Sciences. "This study is important because in a climate that is changing relatively quickly, these techniques allow us to foresee what may happen."The findings, published in "We are not suggesting that such a shift would be a catastrophe," Kemanian said. "It doesn't mean that Iowa will stop producing crops, but it might mean that Iowa farmers adapt to a warmer climate producing two crops in a year or a different mix of crops instead of the dominant corn-soybean rotation. The changes are likely to be gradual, and farmers and the supply chain should be able to adapt. But things will change."The three crops in the study have distinct responses to humidity and temperature, one of the most revealing results of the study, noted Hoffman. In general, corn needs more humidity, sorghum tolerates higher temperatures and soybean is somewhere in between.For each year during the study period, researchers estimated planting dates for every county, based on county-level temperatures to simulate farmer adaptation to cold or warm years, she said. They estimated that planting occurs once the 21-day moving average rises to a crop-specific threshold temperature. Planting temperatures for corn, sorghum and soybean were 50, 59, and 53.6 degrees Fahrenheit, respectively.Corn exhibited a uniquely strong response of increased yield to increasing atmospheric humidity during its critical phase, from before to after flowering, as well as a strong sensitivity to exposure to extreme temperatures, Hoffman explained."Humidity is a factor for all crops studied, but what the data are telling us is that it is more of a factor for corn than it is for soybean or sorghum, and in a very narrow time window," she said. "And by humidity, we mean that soils might be moist, but the data is showing that moisture in the air matters, regardless. That wasn't known before."However, soybean has a strong response to both maximum and minimum temperatures, she said. "All crops had threshold-like responses to high temperature, though we documented a comparatively greater tolerance to high temperature for sorghum at 90.5 F versus a range of 84.2 to 86 F for corn and soybean. We did not describe that response -- machine learning revealed it for us."The research may have implications for companies selling crop insurance, Kemanian suggests."High-temperature swings are damaging. Learning when and by how much for both corn and soybean is critically important," he said. "Crop insurance companies have an interest in this because they need to assess the risk of a given stress happening and how much they will pay as a result."Chris Forest, professor of earth and mineral sciences, Hoffman's doctoral degree adviser was involved in the research. This research builds on earlier work done by Hoffman and the team in sub-Saharan Africa.
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Agriculture & Food
| 2,020 |
May 4, 2020
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https://www.sciencedaily.com/releases/2020/05/200504074720.htm
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Scientists take a step closer to heat-tolerant wheat
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Researchers working on molecular-level responses in crops have taken a step closer to their goal of producing heat-tolerant wheat.
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Smart thermostats tell air conditioners to switch on when the sun is bearing down in the summer and when to shut down to conserve energy. Similarly, plants have Rubisco activase, or Rca for short, that tells the plant's energy-producing enzyme (Rubisco) to kick on when the sun is shining and signals it to stop when the leaf is deprived of light to conserve energy.Today, a team from Lancaster University reports in "We took a wheat Rca (2β) that was already pretty good at activating Rubisco in lower temperatures and swapped out just one of its amino acids with one found in another wheat Rca (1β) that works pretty well in higher temperatures but is rubbish at activating Rubisco -- and the result is a new form of 2β Rca that is the best of both worlds," said Elizabete Carmo-Silva, a senior lecturer at the Lancaster Environment Centre who oversaw this work for a research project called Realizing Increased Photosynthetic Efficiency (RIPE).RIPE is engineering crops to be more productive by improving photosynthesis, the natural process all plants use to convert sunlight into energy and yields. RIPE is supported by the Bill & Melinda Gates Foundation, the U.S. Foundation for Food and Agriculture Research (FFAR), and the U.K. Government's Department for International Development (DFID).Here's the breakdown: naturally occurring wheat Rca 1β has an isoleucine amino acid, works up to 39 degrees Celcius, but isn't great at activating Rubisco, whereas the naturally occurring 2β has a methionine amino acid, works up to about 30 degrees Celcius, and is good at activating Rubisco. Here the team has created a new version of 2β with an isoleucine amino acid that works up to 35 degrees Celcius and is quite good at activating Rubisco."Essentially, 1β is a rubbish enzyme and 2β is sensitive to higher temperatures," Carmo-Silva said. "The cool thing here is that we have shown how this one amino acid swap can make Rca active at higher temperatures without really affecting its efficiency to activate Rubisco, which could help crops kickstart photosynthesis under temperature stress to churn out higher yields."This work was carried out in vitro in E. coli, supported by a Ph.D. studentship by the Lancaster Environment Centre to first author Gustaf Degen. Importantly, these findings will support RIPE's efforts to characterise and improve the Rca of other food crops such as cowpea and soybean, each with multiple different forms of Rca."When looking at cowpea growing regions in Africa, it goes all the way from South Africa with an average around 22 degrees Celcius to Nigeria at about 30, and areas further north get to 38," Carmo-Silva said. "If we can help Rubisco activate more efficiently across these temperatures, that is really powerful and could help us close the gap between yield potential and the reality for farmers who depend on these crops for their sustenance and livelihoods."
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Agriculture & Food
| 2,020 |
May 1, 2020
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https://www.sciencedaily.com/releases/2020/05/200501092920.htm
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Emergence of deadly honey bee disease revealed
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Honey bee colonies from across the UK are increasingly suffering from a viral disease, a new study has shown.
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Publishing their findings in the journal Data collected from visits to over 24,000 beekeepers confirmed that while chronic bee paralysis was only recorded in Lincolnshire in 2007, a decade later it was present in 39 of 47 English and six of eight Welsh counties. The scientists also found that clusters of chronic bee paralysis, where disease cases are found close together, were becoming more frequent.Chronic bee paralysis symptoms include abnormal trembling, an inability to fly, and the development of shiny, hairless abdomens. The disease is caused by a virus known as chronic bee paralysis virus (CBPV), and infected bees die within a week. This leads to piles of dead bees just outside honey bee hives and whole colonies are frequently lost to the disease.Study lead, Professor Budge, from Newcastle University's School of Natural and Environmental Sciences, said: "Our analysis clearly confirms that chronic bee paralysis has been emerging across England and Wales since 2007 and that apiaries owned by professional beekeepers are at greater risk of the disease."The study was completed in association with the Bee Farmers' Association, who represent professional beekeepers in the UK. Rob Nickless, the Chairman of the Bee Farmers' Association, said: "We are pleased to be part of this project and welcome these early results. This is the sort of research that brings practical benefits to the industry -- helping bee farmers at grassroots level to improve honey bee health and increase UK honey production."Professor Budge said: "We do not yet know why colonies of bee farmers are at increased risk from this damaging disease, but many management practices are known to differ significantly between amateur and professional apiarists."The study also investigated whether disease risk was associated with honey bee queen imports. Honey bee queens head up honey bee colonies and beekeepers use imported honey bee queens to replenish their stocks. The scientists used data from 130,000 honey bee imports from 25 countries to show for the first time that the disease was nearly twice as likely in apiaries owned by beekeepers who imported honey bees.This work is being completed as a collaboration between Newcastle and St Andrews Universities, the Bee Farmers' Association and the National Bee Unit of the Animal and Plant Health Agency with funding from the BBSRC The researchers highlight the need for further studies focussing on different virus genotypes, which will be completed at the University of St Andrews.Future work will concentrate on the susceptibility of different honey bee races and comparing the management practices of professional and amateur beekeepers to help discover the reasons behind the current disease emergence. This work will have the potential to reduce or mitigate the damage of this emerging disease to our most important managed pollinator.
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Agriculture & Food
| 2,020 |
April 30, 2020
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https://www.sciencedaily.com/releases/2020/04/200430170930.htm
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Experts apply microbiome research to agricultural science to increase crop yield
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The global demand and consumption of agricultural crops is increasing at a rapid pace. According to the 2019 Global Agricultural Productivity Report, global yield needs to increase at an average annual rate of 1.73 percent to sustainably produce food, feed, fiber and bioenergy for 10 billion people in 2050. In the US, however, agricultural productivity is struggling to keep pace with population growth, highlighting the importance of research into traditional practices as well as new ones.
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In an effort to increase crop yield, scientists at Northern Arizona University's Pathogen and Microbiome Institute (PMI) are working with Purdue University researchers to study the bacterial and fungal communities in soil to understand how microbiomes are impacting agricultural crops. They believe technological advances in microbiome science will ultimately help farmers around the world grow more food at a lower cost.Nicholas Bokulich, a PMI assistant research professor, and Greg Caporaso, an associate professor of biological sciences and director of PMI's Center for Applied Microbiome Science (CAMS), have been testing a long-held farming belief that phylogenetics -- the study of the evolutionary relationship between organisms -- should be used to define crop rotation schedules.The team recently published its findings regarding microbiome research in agricultural food production in Specifically, the traditional approach has been to rotate distantly related crops across different years to maximize plant yield. "One hypothesis for why this may be helpful is that plant pathogens are specific to a single host or to very closely related hosts. If you grow closely related crops in adjacent years, there is a higher chance that pathogens may be lying in wait for their hosts in the second year," Caporaso said. "But this hypothesis has not been directly tested."The team's experiment, supported by a grant from the USDA National Institute of Food and Agriculture, spanned two outdoor growing seasons. In the first year, Purdue scientists Kathryn Ingerslew and Ian Kaplan grew 36 crops and agricultural weeds that differed in evolutionary divergence from the tomato. The experimental plots ranged from tomato (the same species) to eggplant (the same genus as tomato, but a different species) and sweet peppers (the same family as tomato, but in a different genus and species) through corn, wheat and rye, which are much more distant relatives of the tomato.In the second season, the researchers only grew tomatoes on all of the plots. They found that in plots where tomatoes were grown in the first season, the year-two tomato yield was lower than in year one, as they expected. However, there were no significant reductions in tomato yield on any of the other plots. "This result suggests that while crop rotation is indeed important for yield, the effect may not extend beyond the species level," Caporaso said."This outcome was very surprising because the idea that closely related plants should be avoided in rotations is a widely held rule of thumb across the spectrum from small-scale gardening to large-scale agriculture," said Kaplan, a professor of entomology. "The fact that we cannot detect any signature of relatedness on crop yield -- beyond the negative effects of single species monoculture (or tomato after tomato) -- suggests that other factors need to be considered in designing crop rotation programs in sustainable farming systems."Before planting in year two, Caporaso and Bokulich used microbiome sequencing methods to determine the composition of the bacterial and fungal communities in the soil. They found that a microbiome legacy of the year-one crops lived on, although both the soil bacterial and fungal communities were significantly different across the plots of different plants."We're now able to explore the role of microbes and the composition of microbiomes in agricultural systems in far greater depth and resolution than has ever been possible before," Caporaso said. "Those technologies can undoubtedly help us optimize agricultural systems to continuously enrich, rather than deplete, soil over time."Caporaso says his long-term goal with this research direction is to collaborate with organic farmers who are practicing regenerative agriculture techniques. "We can learn how they can use advances in microbiome science to their advantage. I believe that this can help lower their fertilizer costs and water use, and build resiliency and food security in our communities."In a related project funded by the NAU Green Fund as well as through Caporaso's lab, which is focused on software engineering in support of microbiome research, environmental science undergraduate student researcher Christina Osterink plans to prototype a workplace composting program this summer. Her project will involve working with about 10 offices on campus to collect food scraps and deliver them to Roots Micro Farm based in downtown Flagstaff.While diverting food waste from the landfill to an urban farm, Osterink and her team also will track the microbiome of the collected food waste through its transformation via vermicomposting, a worm-based composting method, into high-quality soil. "This will help us develop a more precise understanding of the role of microbes in the composting process as we bring together efforts from throughout NAU's campus as well as local farmers to improve NAU's sustainability and Flagstaff's soil integrity," she said.Caporaso is hopeful findings from Osterink's research can be applied to optimize composting systems and reduce farmers' costs.Caporaso notes that the vermicomposting project represents a new research direction for his lab. "Most of our work at CAMS is related to human health," he said, "but there are at least as many opportunities to apply microbiome research in other areas, such as agricultural science."Meanwhile, the next step in the crop rotation study will be to identify the important factors for plant yield, especially if evolutionary relatedness of species is ruled out."Do we want to rotate crops that thrive with similar soil microbiomes, so that the beneficial bacteria and fungi are already in place to support the next growing season?" Caporaso said. "That would be valuable information for both small urban farms and large industrial operations."
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Agriculture & Food
| 2,020 |
April 28, 2020
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https://www.sciencedaily.com/releases/2020/04/200428142357.htm
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Virus genomes help to explain why a major livestock disease has re-emerged in Europe
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Livestock diseases like bluetongue virus (BTV) can have devastating economic and health consequences, but their origins can be difficult to establish. New research published in the open access journal
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Bluetongue virus, a pathogen that infects sheep and cattle, has caused billions of euros of damage to the European farming industry over the last two decades. In the new study, led by researchers at the University of Glasgow (UK) with a consortium of European collaborators, the authors compared genomes of the virus before and after it re-emerged in France in 2015. BTV first arrived in Europe in 2006 from unknown sources. It was controlled through mass vaccination by 2010, and no cases were reported until it re-emerged in 2015. The authors' genome analyses revealed that during both the 2006 and 2015 outbreaks, BTV accumulated novel mutations in a manner expected for a rapidly evolving virus. During the period in between the two outbreaks, however, the researchers noted a curious lack of mutations, indicating that the virus was likely not circulating during this period. The genetic similarity between the original and re-emergent viruses suggests that the 2015 outbreak was caused by infectious material that somehow arose from the first outbreak.Virus persistence over multiple years in the absence of genetic changes would upset our understanding of virus biology. A more plausible scenario, the authors argue, is that the virus resurfaced after being stored in frozen samples. And since artificial insemination and embryo transfer are widely used in the livestock industry, they say, this transmission mechanism should be evaluated by future work.Prof. Massimo Palmarini, one of the senior authors of the study says: "In order to survive, to be transmitted and to find new hosts, viruses need to replicate. New mutations are an inevitable consequence of this, so viruses can't remain 'frozen in time'. While there is still lots for us to learn about virus biology, the most plausible explanation for our findings is that exposure to infectious material, stored from the earlier outbreak, caused the most recent emergence of this virus in Europe."
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Agriculture & Food
| 2,020 |
April 28, 2020
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https://www.sciencedaily.com/releases/2020/04/200428142353.htm
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Important flowering plants for city-dwelling honey bees
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Trees, shrubs and woody vines are among the top food sources for honey bees in urban environments, according to an international team of researchers. By using honey bees housed in rooftop apiaries in Philadelphia, the researchers identified the plant species from which the honey bees collected most of their food, and tracked how these food resources changed from spring to fall. The findings may be useful to homeowners, beekeepers and urban land managers who wish to sustain honey bees and other bee and pollinator species.
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"We know that cities can support a surprising diversity of bee species; however, cities are complex environments, and traditional floral surveying methods can be hard to implement," said Christina Grozinger, Distinguished Professor of Entomology and director of the Center for Pollinator Research, Penn State. "By analyzing the pollen that honey bees brought back to their colonies and how the weights of these colonies changed every hour, we were able to identify the flowering plants that provide the most nutrition for bees in Philadelphia, and understand how these resources change across the seasons."The researchers installed 12 apiaries, each containing three honey bee colonies, at locations throughout Philadelphia. Each colony was equipped with a pollen trap for capturing incoming pollen and a scale for logging its weight once per hour. The team visited each apiary monthly to collect pollen samples. They sequenced the DNA from the samples to determine which plant genera were present in each sample. Their findings appeared on April 27 in the journal "Ours is the first study to combine two novel techniques -- continuous colony weight monitoring and pollen DNA metabarcoding -- to answer simultaneously the questions of 'what' and 'how much' with respect to the flowers that are available to foraging insects," said Douglas Sponsler, postdoctoral scholar in entomology, Penn State. "Colony weight patterns tell us when resources are plentiful and when they are scarce. Pollen DNA metabarcoding tells us which plants are available at a given time and how the floral community changes through the year."The team found that the availability of floral resources in Philadelphia follows a consistent seasonal pattern -- floral resources are plentiful in spring, scarce in summer, and briefly plentiful again in late summer and early fall before becoming scarce for the remainder of the year.Specifically, trees like maples, oaks and willows were the most important spring pollen sources. During the summer when resources were scarce, crepe myrtle, Japanese pagoda tree and devil's walking stick emerged as important species. In summer and fall, woody vines, such as Virginia creeper, English ivy and autumn clematis, dominated the pollen samples."Vines are not traditionally regarded as major foraging resources for pollinators, and what we discovered in our study system may be a novelty of urban ecosystems," said Sponsler. "Vines such as the ones we found thrive on the vertical surfaces of built environments, and many of them have been introduced by humans as garden plants."According to the researchers, the study highlights at least three actionable findings."Care should be taken to avoid plants with a strong potential to become invasive," said Sponsler. "But as far as ornamentals go, summer-blooming species like Japanese pagoda tree and crepe myrtle might alleviate seasonal shortages of floral resources. In the eastern U.S., native species like eastern redbud, American linden and some varieties of hydrangea are good options for ornamental plantings."Groziner noted that although caution should be taken in extrapolating the findings to cities beyond Philadelphia, the overall consistency of the team's findings with comparable datasets suggests that the patterns seen in the data are likely the same as would be found in similar locations. Grozinger noted that several other studies from their group have found that ornamental plants can provide good nutrition for bees, and often provide season-long blooms. More information on creating gardens for pollinators can be found on the Penn State Master Gardeners Pollinator Garden Certification Program site."Our data can inform urban land management, such as the design of ecologically functional ornamental plantings, while also providing practical guidance to beekeepers seeking to adapt their management activities to floral resource seasonality," Grozinger said.
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Agriculture & Food
| 2,020 |
April 28, 2020
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https://www.sciencedaily.com/releases/2020/04/200428131716.htm
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Agricultural pickers in US to see unsafely hot workdays double by 2050
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The global pandemic has put a focus on essential workers, those we rely on for basic services. Workers who pick crops, from strawberries to apples to nuts, already face harsh conditions harvesting in fields during summer harvest months. Those conditions will worsen significantly over the coming decades.
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A new study from the University of Washington and Stanford University, published online in "Studies of climate change and agriculture have traditionally focused on crop yield projections, especially staple crops like corn and wheat," said lead author Michelle Tigchelaar, a postdoctoral researcher at Stanford University who did the work while at the UW. "This study asks what global warming means for the health of agricultural workers picking fruits and vegetables."The average picker now experiences 21 days each year when the daily heat index -- a mix of air temperature and humidity -- would exceed workplace safety standards. Using projections from climate models, the study shows the number of unsafe days in crop-growing counties will jump to 39 days per season under 2 degrees Celsius warming, which is expected by 2050, and to 62 unsafe days under 4 degrees Celsius warming, which is expected by 2100."I was surprised by the scale of the change -- seeing a doubling of unsafe days by mid-century, then a tripling by 2100. And we think that's a low estimate," Tigchelaar said.The study also shows that heat waves, prolonged stretches of three or more of the hottest days for each county, will occur five times as often, on average, under 2 degrees Celsius of warming.Roughly 1 million people officially are employed in the U.S. picking agricultural crops. The authors used the U.S. Bureau of Labor Statistics job codes to determine their locations. The 20 counties that employ the most pickers all are in California, Washington, Oregon and Florida. The actual number of agricultural workers in the U.S. is estimated at more than 2 million.This population already is vulnerable to health risks. Agricultural workers tend to have lower incomes and less health coverage, a majority say they are not fluent in English, and many do not have legal work status in the U.S., meaning they are less likely to seek medical care. Farmworkers already report more kidney ailments and other conditions related to heat stress.Tigchelaar began the study after a 2017 death in Washington state, when a blueberry picker died during a hot and smoky period. That prompted Tigchelaar, then a postdoctoral researcher at the UW, to think about how agricultural workers are particularly at risk from climate change."The people who are the most vulnerable are asked to take the highest risk so that we, as consumers, can eat a healthy, nutritious diet," Tigchelaar said.The authors also considered what steps might protect agricultural workers. The interdisciplinary team used an occupational health threshold value for heat stress that combines heat generated by physical activity with the external temperature and humidity. The four adaptation strategies they considered were working significantly less vigorously, taking longer breaks, wearing thinner and more breathable protective clothing, and taking breaks in a cooled shelter."This is the first study that I'm aware of that has attempted to quantify the effect of various adaptations, at the workplace level, to mitigate the risk of increased heat exposure with global warming for agricultural workers," said co-author Dr. June Spector, a UW associate professor of environmental and occupational health sciences.Results show that the most effective way to reduce heat stress would be to develop lighter protective clothing that would still shield workers from pesticides or other hazards. And using any three of the four adaptation strategies in combination would be enough to offset the temperature increases.Many workplaces are already protecting workers from heat, said Spector, who conducts research in the UW Pacific Northwest Agricultural Safety and Health Center. This new study helps employers and workers foresee future conditions and think about how to prepare.The authors caution that the study is not an excuse to stop reducing greenhouse gas emissions. Lower emissions can't avoid the temperature increases projected by 2050, but the longer-term adaptation measures considered would have a big impact on farm productivity and profitability."The climate science community has long been pointing to the global south, the developing countries, as places that will be disproportionately affected by climate change," said co-author David Battisti, a UW professor of atmospheric sciences. "This shows that you don't have to go to the global south to find people who will get hurt with even modest amounts of global warming -- you just have to look in our own backyard."
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Agriculture & Food
| 2,020 |
April 28, 2020
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https://www.sciencedaily.com/releases/2020/04/200428112533.htm
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Crops sown in a uniform spatial pattern produce higher yields and reduce environmental impact
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One of the greatest challenges facing humanity is how to grow more food while reducing the negative impacts of agriculture upon the environment. Our ability to do so requires ever-more efficient and sustainable agricultural practices. The promising news is that researchers have found out that the spatial pattern in which a farmer sows their crops is an important determinant of what they will reap.
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"In the vast majority of cases, higher yields and fewer weeds are the result of sowing crops in a more uniform, grid-like pattern, where each plant is equidistant from its neighbouring plants, both within and between rows," says Professor Jacob Weiner of the University of Copenhagen's Department of Plant and Environmental Sciences.Professor Weiner and his colleagues from Northeast Agricultural University in China conducted a large metastudy of research in the area to discover the impact of uniform spatial patterns on crop yields and weed growth. The study, now published in the serial In particular, the researchers looked at three of the world's most widely-cultivated crops: wheat, maize and soybean. In many studies, yields were roughly 20% higher, while one study yielded 60% more wheat and another, up to 90% more soybeans. With regards to weed growth, several studies resulted in more than a 30% reduction in weeds when traditional, less precise sowing was replaced by the uniform sowing pattern."Our own research has demonstrated the positive effects of the uniform sowing of wheat when weeds are present, but the new study shows that this benefit extends to other crops, both with and without competition from weeds" says Professor Weiner.Today, a typical seeding machine sows in a fairly precise distance between rows. However, within each row, the distance between seeds is random, meaning that some plants have close neighbours, while others have distant ones.Conversely, when seeds are sown in uniform grid patterns, roots spread and occupy soil space faster, while more readily and efficiently absorbing nutrients. This helps to reduce the release of nutrients such as nitrogen."From an environmental perspective, it's win-win. There is less nitrogen runoff, and herbicide can be reduced because there are fewer weeds to contend with. This ability to increase yields and mitigate environmental impacts contributes to more sustainable agriculture," according to the the professor.Above ground, the uniform grid pattern is advantageous because crop plants shade one another less during the early part of the growing season. One study estimateded that crop leaves covered the ground several weeks sooner when sown in a uniform sowing pattern."It's a bit like a forest plantation, where trees are planted in a uniform pattern. In this way, there is nothing new to this principle. It just hasn't been seen as important for crops as it is for trees. People didn't believe that a sowing pattern could have such a significant impact for crops. But we were able to conclude that it does," says Jacob Weiner.Technically, this type of precision sowing has been a challenge."But now, there are machines suited for the job and new ones are constantly being developed. This applies to both precision seeders and robots. You might pay more for the machine, but it's a one-time expense that pays itself off," says Jacob Weiner.In the vast majority of cases, an even distribution of crops within rows results in higher yields and fewer weeds. When the distance between rows is reduced as well, even greater outcome are possible.The study also demonstrates that uniform sowing patterns are less effective in drier areas, while more effective in wetter ones.The study was conducted by Ping Lu and Baiwen Jiang from Northeast Agricultural University in Harbin, China and Jacob Weiner from the Department of Plant and Environmental Sciences at the University of Copenhagen.
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Agriculture & Food
| 2,020 |
April 27, 2020
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https://www.sciencedaily.com/releases/2020/04/200427125207.htm
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Engineers develop precision injection system for plants
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While the human world is reeling from one pandemic, there are several ongoing epidemics that affect crops and put global food production at risk. Oranges, olives, and bananas are already under threat in many areas due to diseases that affect plants' circulatory systems and that cannot be treated by applying pesticides.
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A new method developed by engineers at MIT may offer a starting point for delivering life-saving treatments to plants ravaged by such diseases.These diseases are difficult to detect early and to treat, given the lack of precision tools to access plant vasculature to treat pathogens and to sample biomarkers. The MIT team decided to take some of the principles involved in precision medicine for humans and adapt them to develop plant-specific biomaterials and drug-delivery devices.The method uses an array of microneedles made of a silk-based biomaterial to deliver nutrients, drugs, or other molecules to specific parts of the plant. The findings are described in the journal Advanced Science, in a paper by MIT professors Benedetto Marelli and Jing-Ke-Weng, graduate student Yunteng Cao, postdoc Eugene Lim at MIT, and postdoc Menglong Xu at the Whitehead Institute for Biomedical Research.The microneedles, which the researchers call phytoinjectors, can be made in a variety of sizes and shapes, and can deliver material specifically to a plant's roots, stems, or leaves, or into its xylem (the vascular tissue involved in water transportation from roots to canopy) or phloem (the vascular tissue that circulates metabolites throughout the plant). In lab tests, the team used tomato and tobacco plants, but the system could be adapted to almost any crop, they say. The microneedles can not only deliver targeted payloads of molecules into the plant, but they can also be used to take samples from the plants for lab analysis.The work started in response to a request from the U.S. Department of Agriculture for ideas on how to address the citrus greening crisis, which is threatening the collapse of a $9 billion industry, Marelli says. The disease is spread by an insect called the Asian citrus psyllid that carries a bacterium into the plant. There is as yet no cure for it, and millions of acres of U.S. orchards have already been devastated. In response, Marelli's lab swung into gear to develop the novel microneedle technology, led by Cao as his thesis project.The disease infects the phloem of the whole plant, including roots, which are very difficult to reach with any conventional treatment, Marelli explains. Most pesticides are simply sprayed or painted onto a plant's leaves or stems, and little if any penetrates to the root system. Such treatments may appear to work for a short while, but then the bacteria bounce back and do their damage. What is needed is something that can target the phloem circulating through a plant's tissues, which could carry an antibacterial compound down into the roots. That's just what some version of the new microneedles could potentially accomplish, he says."We wanted to solve the technical problem of how you can have a precise access to the plant vasculature," Cao adds. This would allow researchers to inject pesticides, for example, that would be transported between the root system and the leaves. Present approaches use "needles that are very large and very invasive, and that results in damaging the plant," he says. To find a substitute, they built on previous work that had produced microneedles using silk-based material for injecting human vaccines."We found that adaptations of a material designed for drug delivery in humans to plants was not straightforward, due to differences not only in tissue vasculature, but also in fluid composition," Lim says. The microneedles designed for human use were intended to biodegrade naturally in the body's moisture, but plants have far less available water, so the material didn't dissolve and was not useful for delivering the pesticide or other macromolecules into the phloem. The researchers had to design a new material, but they decided to stick with silk as its basis. That's because of silk's strength, its inertness in plants (preventing undesirable side effects), and the fact that it degrades into tiny particles that don't risk clogging the plant's internal vasculature systems.They used biotechnology tools to increase silk's hydrophilicity (making it attract water), while keeping the material strong enough to penetrate the plant's epidermis and degradable enough to then get out of the way.Sure enough, they tested the material on their lab tomato and tobacco plants, and were able to observe injected materials, in this case fluorescent molecules, moving all they way through the plant, from roots to leaves."We think this is a new tool that can be used by plant biologists and bioengineers to better understand transport phenomena in plants," Cao says. In addition, it can be used "to deliver payloads into plants, and this can solve several problems. For example, you can think about delivering micronutrients, or you can think about delivering genes, to change the gene expression of the plant or to basically engineer a plant.""Now, the interests of the lab for the phytoinjectors have expanded beyond antibiotic delivery to genetic engineering and point-of-care diagnostics," Lim adds.For example, in their experiments with tobacco plants, they were able to inject an organism called Agrobacterium to alter the plant's DNA -- a typical bioengineering tool, but delivered in a new and precise way.So far, this is a lab technique using precision equipment, so in its present form it would not be useful for agricultural-scale applications, but the hope is that it can be used, for example, to bioengineer disease-resistant varieties of important crop plants. The team has also done tests using a modified toy dart gun mounted to a small drone, which was able to fire microneedles into plants in the field. Ultimately, such a process might be automated using autonomous vehicles, Marelli says, for agricultural-scale use.Meanwhile, the team continues to work on adapting the system to the varied needs and conditions of different kinds of plants and their tissues. "There's a lot of variation among them, really," Marelli says, so you need to think about having devices that are plant-specific. For the future, our research interests will go beyond antibiotic delivery to genetic engineering and point-of-care diagnostics based on metabolite sampling."The work was supported by the Office of Naval Research, the National Science Foundation, and the Keck Foundation.
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Agriculture & Food
| 2,020 |
April 27, 2020
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https://www.sciencedaily.com/releases/2020/04/200427110151.htm
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Honey bees could help monitor fertility loss in insects due to climate change
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New research from the University of British Columbia and North Carolina State University could help scientists track how climate change is impacting the birds and the bees... of honey bees.
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Heat can kill sperm cells across the animal kingdom, yet there are few ways to monitor the impact of heat on pollinators like honey bees, who are vital to ecosystems and agriculture around the world.In a study published in The proteins could be used as a tool to monitor heat stress in queen bees, and serve as a bellwether for wider insect fertility losses due to climate change."Just like cholesterol levels are used to indicate the risk of heart disease in humans, these proteins could indicate whether a queen bee has experienced heat stress," said lead author Alison McAfee, a biochemist at the Michael Smith Labs at UBC and postdoc at NC State. "If we start to see patterns of heat shock emerging among bees, that's when we really need to start worrying about other insects."Although honey bees are quite resilient compared to other non-social insects, they are a useful proxy because they are managed by humans all over the world and are easy to sample.The researchers were particularly interested in queen bees because their reproductive capacity is directly linked to the productivity of a colony. If the sperm stored by a queen is damaged, she can "fail" when she no longer has enough live sperm to produce enough drones and worker bees to maintain a colony."We wanted to find out what 'safe' temperatures are for queen bees and explore two potential routes to heat exposure: during routine shipping and inside colonies," said McAfee. "This information is really important for beekeepers, who often have no way to tell what condition the queens they receive are in. That can have a really dramatic impact on their quality and quality of their colonies."First McAfee established what the threshold for queen "failure" was, and how much heat they could withstand by exposing them to a range of temperatures and durations."Our data suggests that temperatures between 15 to 38 degrees Celsius are safe for queens," said McAfee. "Above 38 degrees, the percentage of live sperm dropped to or below the level we see in failed queens compared to healthy queens, which is an 11.5 per cent decrease from the normal 90 per cent."The researchers then placed temperature loggers in seven domestic queen shipments via ground and one by air. They found that one package experienced a temperature spike to 38 degrees Celsius, while one dropped to four degrees Celsius."These findings can help create better guidelines for safe queen bee transportation and help buyers and sellers track the quality of queens," said co-author Leonard Foster, a professor at the Michael Smith Labs at UBC.While bee colonies are generally thought to be good at regulating the temperature inside hives, the researchers wanted to know how much the temperature actually fluctuated. They recorded the temperatures in three hives in August in El Centro, California, when the ambient temperature in the shade below each hive reached up to 45 degrees Celsius.They found that in all three hives, the temperatures at the two outermost frames spiked upwards of 40 degrees Celsius for two to five hours, while in two of the hives, temperatures exceeded 38 degrees Celsius one or two frames closer to the core."This tells us that a colony's ability to thermoregulate begins to break down in extreme heat, and queens can be vulnerable to heat stress even inside the hive," said co-author Jeff Pettis, an independent research consultant and former USDA-ARS scientist.Having established these key parameters, the researchers will continue to refine the use of the protein signature to monitor heat stress among queen bees."Proteins can change quite easily, so we want to figure out how long these signatures last and how that might affect our ability to detect these heat stress events," said McAfee. "I also want to figure out if we can identify similar markers for cold and pesticide exposure, so we can make more evidence-based management decisions. If we can use the same markers as part of a wider biomonitoring program, then that's twice as useful."
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Agriculture & Food
| 2,020 |
April 27, 2020
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https://www.sciencedaily.com/releases/2020/04/200427091649.htm
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Spread of early dairy farming across Western Europe
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A study has tracked the shift from hunter-gatherer lifestyles to early farming that occurred in prehistoric Europe over a period of around 1,500 years.
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An international team of scientists, led by researchers at the University of York, analysed the molecular remains of food left in pottery used by the first farmers who settled along the Atlantic Coast of Europe from 7,000 to 6,000 years ago.The researchers report evidence of dairy products in 80% of the pottery fragments from the Atlantic coast of what is now Britain and Ireland. In comparison, dairy farming on the Southern Atlantic coast of what is now Portugal and Spain seems to have been much less intensive, and with a greater use of sheep and goats rather than cows.The study confirms that the earliest farmers to arrive on the Southern Atlantic coast exploited animals for their milk but suggests that dairying only really took off when it spread to northern latitudes, with progressively more dairy products processed in ceramic vessels.Prehistoric farmers colonising Northern areas with harsher climates may have had a greater need for the nutritional benefits of milk, including vitamin D and fat, the authors of the study suggest.Senior author of the paper, Professor Oliver Craig from the Department of Archaeology at the University of York, said: "Latitudinal differences in the scale of dairy production might also be important for understanding the evolution of adult lactase persistence across Europe. Today, the genetic change that allows adults to digest the lactose in milk is at much higher frequency in Northwestern Europeans than their southern counterparts."The research team examined organic residues preserved in Early Neolithic pottery from 24 archaeological sites situated between Portugal and Normandy as well as in the Western Baltic.They found surprisingly little evidence for marine foods in pottery even from sites located close to the Atlantic shoreline, with plenty of opportunities for fishing and shellfish gathering. An exception was in the Western Baltic where dairy foods and marine foods were both prepared in pottery.Lead author of the paper, Dr Miriam Cubas, said: "This surprising discovery could mean that many prehistoric farmers shunned marine foods in favour of dairy, but perhaps fish and shellfish were simply processed in other ways."Our study is one of the largest regional comparisons of early pottery use. It has shed new light on the spread of early farming across Atlantic Europe and showed that there was huge variety in the way early farmers lived. These results help us to gain more of an insight into the lives of people living during this process of momentous change in culture and lifestyle -- from hunter-gatherer to farming."
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Agriculture & Food
| 2,020 |
April 24, 2020
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https://www.sciencedaily.com/releases/2020/04/200424132659.htm
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Dramatic loss of food plants for insects
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Plummeting insect numbers are becoming a concern. Academic discourse focused on three main causes: the destruction of habitats, pesticides in agriculture and the decline of food plants for insects. A team of researchers from the Universities of Bonn and Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL have now demonstrated for the first time that the diversity of food plants for insects in the canton of Zurich has dramatically decreased over the past 100 years or so. This means that bees, flies and butterflies are increasingly deprived of their food base. The study, which is representative for all of Central Europe, has now been published in the journal "
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"Over the past 100 years, there has been a general decline in food plants for all kinds of insects in the canton of Zurich," says Dr. Stefan Abrahamczyk from the Nees Institute for Biodiversity of Plants at the University of Bonn. The homogenization of the originally diverse landscape has resulted in the disappearance of many habitats, especially the wetlands, which have shrunk by around 90 percent. Human settlements have spread more and more at the expense of cultivated land, and the general intensification of pasture and arable farming has led to a widespread depletion of meadows and arable habitats. The researchers compared the abundance of food plants of different insect groups, based on current mapping for the years 2012 to 2017, with data-based estimates from the years 1900 to 1930 in the canton of Zurich (Switzerland).The food plants of specialized groups of flower visitors are particularly affected by the decline. For instance, the Greater Knapweed (Centaurea scabiosa) is pollinated by bumblebees, bees and butterflies, as their tongues are long enough to reach the nectar. The decline is particularly dramatic for plant species that can only be pollinated by a single group of insects. In the case of Aconite (Aconitum napellus), for example, this can only be done by bumblebees because the plant's toxin evidently does not affect them.Overall, all plant communities have become much more monotonous, with just a few dominant common species. "It's hard for us to imagine what vegetation looked like 100 years ago," says Dr. Michael Kessler from the Department of Systematic and Evolutionary Botany at the University of Zurich. "But our data show that about half of all species have experienced significant decline in their abundance, while only ten percent of the species have increased."Residents with appropriate botanical knowledge helped with the current survey. They mapped the entire canton of Zurich by plotting an area of one square kilometer each at intervals of three kilometers. The focus here was on the different types of vegetation and the abundance of different plants. "Without the assistance of more than 250 volunteers, who not only mapped the current flora but also processed the historical collections, a project of this scope would not have been feasible," says Dr. Thomas Wohlgemuth of the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, who initiated the mapping project ten years ago with the Zurich Botanical Society.The most important source on the earlier flora in the canton of Zurich was the unpublished manuscript of Eugen Baumann, a collection of about 1200 handwritten pages. It contains precise and detailed information on the abundance and distribution of plant species before 1930. Dr. Abrahamczyk researched which of the listed species belong to those flowering plants that are visited by insects in search of pollen and nectar. The "customers" include bees, bumblebees, wasps, butterflies, hoverflies, flies and beetles.Dr. Abrahamczyk has been working on pollination biology for about ten years. He wrote his doctoral thesis at the University of Zurich, then conducted research at the LMU Munich and joined the Nees Institute of the University of Bonn in 2014. When, in late 2018, his former doctoral supervisor, Dr. Michael Kessler, suggested that the recently completed mapping of the canton's flora be combined with pollinator data, Dr. Abrahamczyk was immediately enthusiastic -- also because this subject is highly topical. "The laborious literature search and analysis then took some time, and now the study could finally be published," says the scientist from the University of Bonn. "The results are transferable to the whole of Central Europe with minor regional restrictions."
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Agriculture & Food
| 2,020 |
April 23, 2020
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https://www.sciencedaily.com/releases/2020/04/200423212614.htm
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No time to waste to avoid future food shortages
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During the past few weeks, empty supermarket shelves, without pasta, rice and flour due to panic buying, has caused public concerns about the possibility of running out of food. Australian farmers have reassured consumers saying that the country produces enough food to feed three times its population. However, will this statement remain true in ten to twenty years in a country severely affected by climate change? The answer is yes, if we are prepared for this and if there is continuous funding towards creating solutions to increase crop production.
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"Plant scientists are punching above their weight by participating in global, interdisciplinary efforts to find ways to increase crop production under future climate change conditions. We essentially need to double the production of major cereals before 2050 to secure food availability for the rapidly growing world population," says ANU Professor Robert Furbank from the ARC Centre of Excellence for Translational Photosynthesis (CoETP)."It is similar to finding a virus vaccine to solve a pandemic, it doesn't happen overnight. We know that Australia's agriculture is going to be one area of the world that is most affected by climate extremes, so we are preparing to have a toolbox of plant innovations ready to ensure global food security in a decade or so, but to do this we need research funding to continue," Professor Furbank says.Several examples of these innovative solutions were published recently in a special issue on Food Security Innovations in Agriculture in the Co-editor of the Special Issue, ANU Professor John Evans, says that this publication highlights the now widely accepted view that improving photosynthesis -- the process by which plants convert sunlight, water and CO2 into organic matter -- is a new way to increase crop production that is being developed."We are working on improving photosynthesis on different fronts, as the articles included in this special issue show, from finding crop varieties that need less water, to tweaking parts of the process in order to capture more carbon dioxide and sunlight. We know that there is a delay of at least a decade to get these solutions to the breeders and farmers, so we need to start developing new opportunities now before we run out of options," says Professor Evans, CoETP Chief Investigator.The special issue includes research solutions that range from traditional breeding approaches to ambitious genetic engineering projects using completely different ends of the technological spectrum; from robot tractors, to synthetic biology. All these efforts are focused on finding ways to make crops more resistant to drought and extreme climate conditions and being more efficient in the use of land and fertilisers."Our research is contributing to providing food security in a global context, and people often ask what that has to do with Australian farmers and my answer is everything. Aside from the fact that economy and agriculture are globally inter-connected, if Australian farmers have a more productive resilient and stable crop variety, they are able to plan for the future, which turns into a better agribusiness and at the same time, ensures global security across the world," says Professor Furbank.This research has been funded by the Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis (CoETP), led by the Australian National University, which aims to improve the process of photosynthesis to increase the production of major food crops such as sorghum, wheat and rice.The Journal of Experimental Botany special issue on Innovations in Agriculture for Food Security (Volume 71, Issue 7, 6 April 2020) is available to view online at:
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Agriculture & Food
| 2,020 |
April 23, 2020
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https://www.sciencedaily.com/releases/2020/04/200423130447.htm
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Good news for the wheat-sensitive among us
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New research has heralded a promising step for sufferers of wheat sensitivity or allergy.
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A joint project between Edith Cowan University (ECU) in Australia and CSIRO has revealed key insights about the proteins causing two of the most common types of wheat sensitivity -- non-coeliac wheat sensitivity and occupational asthma (baker's asthma).With an estimated 10 per cent of people suffering from wheat sensitivity or allergy causing a raft of chronic health issues, researchers are developing tests that will help the production of low-allergen wheat varieties in the future.ECU Professor of Food and Agriculture Michelle Colgrave led the investigation."We have known for a long time that certain wheat proteins can trigger an immune response in some people, but now we have developed a way to detect and quantify these proteins," Professor Colgrave said."We looked a group of proteins called alpha-amylase/trypsin inhibitors (ATIs), which are known to trigger the intestinal inflammation and chronic ailments associated with wheat intolerance in some people."These ATI proteins are commonly found in wheat and play an important role in plant defence against pests and also act as an important nutrient for plant growth and human nutrition."The research has resulted in a reference map of wheat ATI proteins across a diverse range of wheat varieties that represent more than 80 per cent of the genetic diversity found in commercial bread wheats.The researchers developed an innovative new technique to specifically measure 18 of these proteins, which will help breeders to select varieties with low ATI protein levels in the future or food manufacturers to detect these proteins in food."This is a promising step towards future wheat breeding programs that aim to produce safe and healthy wheat varieties to meet the needs of consumers that currently rely on total wheat avoidance," Professor Colgrave said.This research, which was funded by CSIRO, was published in the
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Agriculture & Food
| 2,020 |
April 23, 2020
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https://www.sciencedaily.com/releases/2020/04/200423130410.htm
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Gene-editing protocol for whitefly pest opens door to control
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Whiteflies are among the most important agricultural pests in the world, yet they have been difficult to genetically manipulate and control, in part, because of their small size. An international team of researchers has overcome this roadblock by developing a CRISPR/Cas9 gene-editing protocol that could lead to novel control methods for this devastating pest.
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According to Jason Rasgon, professor of entomology and disease epidemiology, Penn State, whiteflies (Bemisia tabaci) feed on many types of crop plants, damaging them directly through feeding and indirectly by promoting the growth of fungi and by spreading viral diseases."We found a way to genetically modify these insects, and our technique paves the way not only for basic biological studies of this insect, but also for the development of potential genetic control strategies," he said.The team's results appeared on April 21 in The CRISPR/Cas9 system comprises a Cas9 enzyme, which acts as a pair of 'molecular scissors' that cuts DNA at a specific location on the genome so bits of DNA can be added or removed, and a guide RNA, that directs the Cas9 to the right part of the genome."Gene editing by CRISPR/Cas9 is usually performed by injecting the gene-editing complex into insect embryos, but the exceedingly small size of whitefly embryos and the high mortality of injected eggs makes this technically challenging," said Rasgon. "ReMOT Control (Receptor-Mediated Ovary Transduction of Cargo), a specific type of CRISPR/Cas9 technique developed in my lab, circumvents the need to inject embryos. Instead, you inject the gene-editing complex which is fused to a small ovary-targeting molecule called BtKV, into adult females and the BtKV guides the complex into the ovaries."To explore the use of ReMOT Control in whiteflies, the team targeted the "white" gene, which is involved in eye color. When this gene is functioning normally, whiteflies have brown eyes, but when it is non-functional due to mutations, the insects is supposed to have white eyes. The team found that ReMOT Control generated mutations that resulted in juvenile insects with white eyes that turned red as they developed into adults."Tangentially, we learned a bit about eye color development," said Rasgon. "We expected the eyes to remain white and were surprised when they turned red. Importantly, however, we found that the mutations we generated using ReMOT Control were passed on to offspring, which means that a change can be made that is inherited to future generations."Rasgon said the team hopes its proof-of-principle study will allow scientists to investigate the same strategy using genes that affect the ability for the insects to transmit viral pathogens of crop plants to help control the insects and protect crops."This technique can be used for any application where you want to delete any gene in whiteflies, for basic biology studies or for the development of potential genetic control strategies," he said.
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Agriculture & Food
| 2,020 |
April 22, 2020
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https://www.sciencedaily.com/releases/2020/04/200422151137.htm
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Sweet potato microbiome research important first step towards improving yield
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Grown around the world, sweet potatoes are an important source of nutrition particularly in sub-Saharan African and Asian diets. Sweet potatoes are especially significant to sub-Saharan Africa as a source of Vitamin A, a nutrient commonly deficient in the region. While China currently produces the most sweet potatoes by country, sub-Saharan Africa has more land devoted to sweetpotatoes and continues to expand production. Farmers elsewhere are also increasingly growing sweetpotatoes.
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Despite the importance of sweet potato, little is known about the sweet potato microbiome. "A plant's microbiome profoundly impacts its health and development," explains Brooke Bissinger, an entomologist who recently published a study on sweet potatoes in Bissinger and her colleagues work for AgBiome which was funded by the Bill & Melinda Gates Foundation to identify and develop beneficial microbes that would protect sweet potatoes in the developing world from insects. They used this opportunity to characterize the sweet potato microbiome in order to inform their project and provide information for other researchers interested in similar work.They found that, similar to more popularly studied crops, the sweet potato microbiome follows the two-step model of development."We demonstrated a striking variability in the microorganisms that make up the sweet potato microbiome across a single farm. Despite this variability, we found commonalities in how the microbiome develops across fields within a single sweet potato farm and across two farms in the same region," says Charles Pepe-Ranney, microbial genomics data scientist and lead author of the paper.This is the first study to characterize the sweet potato microbiome using modern, next-generation sequencing technology -- an important first step towards leveraging the microbiome to improve sweet potato yield."Also of note, our study suggests that the sweet potato presents a strong ecological challenge to its endophytes (microbes that live inside a plant)," says Pepe-Ranney. "If we are going to develop a sweet potato endophyte that protects sweetpotatoes from pests, for example, this sweet potato-beneficial endophyte must be able to withstand the strong ecological pressure from the sweet potato itself."
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Agriculture & Food
| 2,020 |
April 22, 2020
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https://www.sciencedaily.com/releases/2020/04/200422112307.htm
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Effective way to replenish threatened plants
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From two seeds grew a thousand plants.
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University of Guelph researchers used advanced cloning techniques to give the threatened Hill's thistle a fighting chance.This cutting-edge propagation method could rejuvenate the population of other threatened and endangered plant species, said lead researcher Prof. Praveen Saxena, Department of Plant Agriculture.Published recently in the journal "A very small amount of plant material can produce large numbers of plants for conservation purposes," said Saxena, who heads the Gosling Research Institute for Plant Preservation (GRIPP) at U of G.The conventional method of planting seeds to reintroduce Hill's thistle has shown limited success due to low flowering and low germination rates."The major goal of our research is to preserve threatened and endangered plant biodiversity through the application of in vitro culture technologies that can be used to prevent species loss in the field," said, Saxena, who worked on the study with fellow GRIPP researchers Bita Sheikholeslami, Christina Turi and Mukund Shukla. "We wanted to test our model for its practical utility in a real-life situation, when lab-generated plants are transferred to harsh natural sites."Parks Canada provided the team with 29 seeds, of which only two germinated. Those two seeds sprouted enough plant material to grow 1,000 plants in the lab; 300 were transplanted back into the Bruce Peninsula National Park in southern Ontario.The 300 plants were planted in 12 sites in the national park in summer 2017. The survival rate ranged from 67 to 99 per cent, with nearly all of these plants surviving the winter. Shoot regeneration and flowering occurred in most sites."Micropropagation is a good approach for Hill's thistle because germplasm can be stored for long-term in our GRIPP facility to conserve the limited genetic diversity, while the threats to the declining populations can be managed through reintroduction of micropropagated plants," said Shukla. "This extensive study provides solid evidence of the usefulness of in vitro-grown plants."The Hill's thistle grows in scarce Great Lakes areas known as open alvar grasslands. In Ontario, the flowering plant, which supports the life cycles of rare bees and other pollinators, is found mostly on the Bruce Peninsula and Manitoulin Island.It is listed as a threatened plant species in the province, and one likely to become endangered if steps are not taken to protect it. A lack of suitable habitat due to the encroachment of trees and shrubs, as well as cottage development and quarrying activity in its natural habitat, have contributed to the decline."In general, plant biodiversity is important for human lives, as well as animals and microbes, as it is critical to their survival because of the oxygen, food and medicine they provide," Saxena said. "A complete ecological system is not possible without plant biodiversity. We are optimistic that the CPR model will prove to be an important tool in saving plant diversity, including important food and medicinal crops."
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Agriculture & Food
| 2,020 |
April 22, 2020
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https://www.sciencedaily.com/releases/2020/04/200422091153.htm
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How atrazine regulations have influenced the environment
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To combat weeds, farmers use a variety of tools and methods. By understanding the strengths and downfalls of each tool, a farmer can make the best decisions for his or her operation to keep pesky weeds out of the field.
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One tool farmers can turn to for weed control is applying herbicides. New research is helping us understand a specific herbicide even better: atrazine.Atrazine is one of the most common herbicides used in the United States. It can be used to manage weeds in crops like corn, sorghum, sugarcane and turf. The chemical kills weeds by preventing photosynthesis in the plant.A benefit of herbicides, like those with atrazine, is that they reduce the need for tillage. In addition to its effects on soil health, tillage can increase erosion of precious soil. Reducing tillage conserves our soil by preventing erosion and maintaining healthy soil structure.A downfall of atrazine, though, is that it can sometimes make its way into streams and rivers.After the chemical is applied to a field, atrazine breaks down in the soil and turns into another compound, called deethylatrazine (DEA). This is a good thing, since DEA is less toxic to aquatic organisms than atrazine.In recent years, atrazine use has been decreasing. However, despite the decrease in atrazine use, concentrations of the secondary compound, DEA, have been increasing.Karen Ryberg and her team thought there must be more to this puzzle than just atrazine use.Ryberg, who works at the United States Geological Survey, wanted to determine the factors, other than usage, that influence trends in herbicide concentrations in streams.The most common conversion of atrazine to DEA is through the activity of soil microbes -- like fungi and bacteria. Therefore, atrazine breaks down quicker when it has more contact with soil microorganisms."Based on previous studies, we predicted factors affecting the atrazine concentrations in streams," says Ryberg. "These included that corn acres in the watershed, weather, climate and management practices.""In our study, we used existing data from 2002 to 2012 spanning many areas of the country," explains Ryberg. Then models were used to analyze the data and test the team's predictions of what caused the atrazine and DEA trends in the streams.In the 1990s, new regulations addressed surface water contamination concerns. These regulations lowered application rates of atrazine for crops, and even prohibited its use near water wells. The goal was to reduce the overall concentration of atrazine in water."Concentration and use trends show that past atrazine regulations, especially in the Midwest, were successful," says Ryberg. "More of the atrazine broke down into DEA before reaching streams."Despite an increase in the amount of corn acres grown between 2002 and 2012, the study showed atrazine use decreased in most areas of the United States.Ryberg's study also discovered that atrazine turns into DEA faster in dry areas without tile drainage. Tile drains can be installed underground in farm fields to help move water and prevent flooding. Tile drains are like stormwater drains for farm fields.Because tile drains help water from the field move faster through underground pipes, the water has less time to come in contact with soil. Therefore, soil microorganisms have less time to break down atrazine to DEA before water carries it out of the field toward nearby streams.This finding means there may be more challenges with atrazine levels in the future. As farmers anticipate climate change and wetter field conditions, more tile drains may be needed in order to grow crops in adequate soil conditions.Moving forward, Ryberg would like to build on this research for monitoring pesticides. "Ongoing monitoring is important to understand the degradation and transport processes of pesticides," explains Ryberg.Farmers will continue to adapt to changing conditions, including weed communities. Pesticide usage will change, and it is an ongoing challenge to monitor for new pesticides or mixtures of pesticides in the environment.
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Agriculture & Food
| 2,020 |
April 22, 2020
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https://www.sciencedaily.com/releases/2020/04/200422091151.htm
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Study sheds light on unique culinary traditions of prehistoric hunter-gatherers
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Hunter-gatherer groups living in the Baltic between seven and a half and six thousand years ago had culturally distinct cuisines, analysis of ancient pottery fragments has revealed.
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An international team of researchers analysed over 500 hunter-gatherer vessels from 61 archaeological sites throughout the Baltic region.They found striking contrasts in food preferences and culinary practices between different groups -- even in areas where there was a similar availability of resources. Pots were used for storing and preparing foods ranging from marine fish, seal and beaver to wild boar, bear, deer, freshwater fish hazelnuts and plants.The findings suggest that the culinary tastes of ancient people were not solely dictated by the foods available in a particular area, but also influenced by the traditions and habits of cultural groups, the authors of the study say.A lead author of the study, Dr Harry Robson from the Department of Archaeology at the University of York, said: "People are often surprised to learn that hunter-gatherers used pottery to store, process and cook food, as carrying cumbersome ceramic vessels seems inconsistent with a nomadic life-style."Our study looked at how this pottery was used and found evidence of a rich variety of foods and culinary traditions in different hunter-gatherer groups."The researchers also identified unexpected evidence of dairy products in some of the pottery vessels, suggesting that some hunter-gatherer groups were interacting with early farmers to obtain this resource.Dr Robson added: "The presence of dairy fats in several hunter-gatherer vessels was an unexpected example of culinary 'cultural fusion'. The discovery has implications for our understanding of the transition from hunter-gatherer lifestyles to early farming and demonstrates that this commodity was either exchanged or perhaps even looted from nearby farmers."Lead author of the study, Dr Blandine Courel from the British Museum, added: "Despite a common biota that provided lots of marine and terrestrial resources for their livelihoods, hunter-gatherer communities around the Baltic Sea basin did not use pottery for the same purpose."Our study suggests that culinary practices were not influenced by environmental constraints but rather were likely embedded in some long-standing culinary traditions and cultural habits."The study, led by the Department of Scientific Research at the British Museum, the University of York and the Centre for Baltic and Scandinavian Archaeology (Stiftung Schleswig-Holsteinische Landesmuseen, Germany), used molecular and isotopic techniques to analyse the fragments of pottery.Senior author, Professor Oliver Craig from the Department of Archaeology at the University of York, said: "Chemical analysis of the remains of foods and natural products prepared in pottery has already revolutionized our understanding of early agricultural societies, we are now seeing these methods being rolled out to study prehistoric hunter-gatherer pottery. The results suggest that they too had complex and culturally distinct cuisines."Organic residue analysis shows sub-regional patterns in the use of pottery by Northern European hunter-gatherers is published in
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Agriculture & Food
| 2,020 |
April 20, 2020
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https://www.sciencedaily.com/releases/2020/04/200420125512.htm
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Changes in snowmelt threaten farmers in western US
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Farmers in parts of the western United States who rely on snowmelt to help irrigate their crops will be among the hardest hit in the world by climate change, a new study reveals.
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In an article published today in They then projected changes in snowmelt and rainfall runoff if the Earth warms by 2 or 4 degrees Celsius (about 3 ½ or 7 degrees Fahrenheit), which will potentially put snow-dependent basins at risk.The findings pinpointed basins globally most at risk of not having enough water available at the right times for irrigation because of changes in snowmelt patterns. Two of those high-risk areas are the San Joaquin and Colorado river basins in the western United States."In many areas of the world, agriculture depends on snowmelt runoff happening at certain times and at certain magnitudes," said Yue Qin, assistant professor of geography and a core faculty of the Sustainability Institute at The Ohio State University."But climate change is going to cause less snow and early melting in some basins, which could have profound effects on food production."Qin, lead author of the study, designed the research with Nathaniel Mueller, assistant professor at Colorado State University, and Steven Davis, associate professor at the University of California, Irvine.Under the 4-degree Celsius warming scenario, the researchers project that the share of irrigation water demand met by snowmelt in the San Joaquin Basin decreases from 33 percent to 18 percent. In the Colorado Basin, the share of water demand met by snowmelt decreases from 38 percent to 23 percent.Other basins in which agriculture is at particular risk because of changes in snowmelt are located in southern Europe, western China and Central Asia.Depending on both the magnitude and the timing, rainfall runoff may be able to compensate for declines in snowmelt runoff in meeting irrigation water demand -- but only for some basins, the researchers calculated."In many basins, future changes in rainfall do not compensate for the lost snowmelt in crops' growing seasons," Mueller said.The San Joaquin, for example, is one basin where increases in rainfall runoff won't be able to make up for snowmelt decline when irrigation is most needed.The researchers evaluated the potential availability of reservoir storage and groundwater to help satisfy the additional irrigation need created by less snowmelt and early melting. In some basins, those additional requirements would pose great challenges in trying to make up for changing snowmelt patterns."Irrigation demands not met by rainfall or snowmelt currently already represent more than 40 percent of reservoir water storage in many Asian and North American basins," Davis said."And in a warming world, agriculture won't be the only added demand on reservoirs and other alternative water supplies like groundwater."In the San Joaquin Basin, findings suggested that 14 percent of irrigation water demand must be met by new alternative sources under a 4-degree Celsius warming scenario. In the Colorado Basin, the figure would be 9 percent.The study also examined which crops globally were at most at risk because of snowmelt changes resulting from climate change. Findings showed that rice and cotton in northern hemisphere summer, or wheat and managed grassland in spring, were particularly snow-dependent.For the study, researchers used data on monthly rainfall and snowmelt runoff globally from 1985 to 2015 from a dataset called TerraClimate. They then calculated monthly irrigation water consumption for a variety of crops.Comparing historical runoff and total surface water consumption, they estimated monthly snowmelt and rainfall runoff consumption as well as demand for alternative water sources in each major river basin.They then used climate models to project snowmelt and rainfall runoff in each basin if global mean temperatures rise 2 degrees or 4 degrees Celsius above pre-industrial conditions.Qin said the results of the study could be used to prioritize and inform methods to minimize the impact of changing snowmelt on water supplies for agriculture. In some cases, policymakers may have to consider extra groundwater pumping and reservoir development.Limits may also need to be placed on water demand, such as by increasing crop water productivity, Qin noted."We need to find ways to help those basins that will most need to adapt to the coming changes," she said.The study was supported by the Foundation for Food and Agriculture Research, the U.S. National Science Foundation and the German Federal Ministry of Education and Research.Other co-authors on the study were from University of California, Irvine; University of California, Merced; University of Idaho; University of Göttingen; Dartmouth College; and Columbia University.
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Agriculture & Food
| 2,020 |
April 20, 2020
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https://www.sciencedaily.com/releases/2020/04/200420125508.htm
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Picking up threads of cotton genomics
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Come harvest time, the cotton fields look like popcorn is literally growing on plants, with fluffy white bolls bursting out of the green pods in every direction. There are 100 million families around the world whose livelihoods depend on cotton production, and the crop's annual economic impact of $500 billion worldwide underscores its value and importance in the fabric of our lives.
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In the United States, cotton production centers around two varieties: 95 percent of what is grown is known as Upland cotton (Gossypium hirsutum), while the remaining 5 percent is called American Pima (G. barbadense.) These are two of the five major lineages of cotton; G. tomentosum, G. mustelinum, and G. darwinii are the others. All of these cotton lineages have genomes approximately 2.3 billion bases or Gigabases (Gb) in size, and are hybrids comprised of cotton A and cotton D genomes.A multi-institutional team including researchers at the U.S. Department of Energy (DOE) Joint Genome Institute (JGI), a DOE Office of Science User Facility located at Lawrence Berkeley National Laboratory (Berkeley Lab) has now sequenced and assembled the genomes of these five cotton lineages. Senior authors of the paper published April 20, 2020 in "The goal has been for all this new cotton work, and even the original cotton project was to try to bring in molecular methods of breeding into cotton," said Schmutz, who heads JGI's Plant Program. He and Grimwood were also part of the JGI team that contributed to the multinational consortium of researchers that sequenced and assembled the simplest cotton genome (G. raimondii) several years ago. Studying the cotton genomes provides breeders with insights on crop improvements at a genetic level, including why having multiple copies of their genomes (polyploidy) is so important to crops. Additionally, cotton is almost entirely made up of cellulose and it is a fiber model to understand the molecular development of cellulose.The genomes of all five cotton lineages and of cotton D are available for comparative analysis on JGI's plant data portal Phytozome, which is a community repository and resource for plant genomes. They are annotated with the JGI Plant Annotation pipeline, which provides high quality comparisons of these genomes within themselves and to other plant genomes."Globally, cotton is the premier natural fiber crop of the world, a major oilseed crop, and important cattle feed crop," noted David Stelly, another study co-author at Texas A&M University. "This report establishes new opportunities in multiple basic and applied scientific disciplines that relate directly and indirectly to genetic diversity, evolution, wild germplasm utilization and increasing the efficacy with which we use natural resources for provisioning society."The comparative analysis of the five cotton genomes identified unique genes related to fiber and seed traits in the domesticated G. barbadense and G. hirsutum species. Unique genes were also identified in the other three wild species. "We thought, 'In all of these wild tetraploids, there will be many disease resistance genes that we can make use of,'" Schmutz said. "But it turns out there isn't really that kind of diversity in the wild in cotton. And this is amazing to me for a species that was so widely distributed."In the field, growers can easily distinguish the cotton species by traits such as flower color, plant height, or fiber yield. To the team's surprise, even though the major cotton lineages had dispersed and diversified over a million years ago, their genomes were "remarkably" stable. "We thought we were sequencing the same genome multiple times," Schmutz recalled. "We were a little confused because they were so genetically similar.""The results described in this Assembling cotton's large and complex genome means being selective in choosing which team to financially support, Jones added. "We must be careful who we ask to take on these projects due to their difficulty and complexity, but we have been extremely pleased with Jeremy, Jane and their team. Many groups assemble genomes, but very few do it so well that it stands the test of time and is considered the gold standard by the world cotton community. This is one such example."Jones noted that he talks to growers about Cotton Inc.'s long-term investment in crop research. "What I have told our growers is, 'Think of these reference genomes as a surgeon's knowledge, and of gene editing as a new tool. In order to know exactly where to use your incredibly precise tool, you have to know where to use it, which exact base or series of bases you have to alter.' Why should we invest in something that may not be an immediate benefit to us for a decade? We believe this basic research has to occur in order to drive the research. Oftentimes, these things take not five or eight years, but sometimes 10 or 15 years, because the technology develops over time."
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Agriculture & Food
| 2,020 |
April 20, 2020
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https://www.sciencedaily.com/releases/2020/04/200420125439.htm
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Aquaculture at the crossroads of global warming and antimicrobial resistance
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Aquaculture -- rearing aquatic organisms such as fish and shellfish -- plays a vital role in food security in many countries (it supplies more than half of the aquatic animals consumed by humans worldwide). It is particularly important for developing countries, for instance in Asia, which accounts for 90% of global output.
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Fish farmers use large quantities of antimicrobials to treat or prevent disease on their farms. However, when used inappropriately, antimicrobials are ineffective and foster the development of resistant bacteria.Researchers from IRD and CIRAD belonging to the Institute of Evolution Sciences of Montpellier's Fish Diversity and Aquaculture team (DIVA, UMR ISEM) examined data from more than 400 scientific articles referring to over 10,000 bacteria of aquacultural origin from 40 countries. That meta-analysis allowed them to study the effect of temperature on the mortality rate of aquatic animals infected with pathogenic bacteria commonly found in aquaculture. They then conducted a systematic review on the abundance of resistant bacteria found on fish farms and calculated the Multi-Antibiotic Resistance (MAR) index for 40 countries."Our results show that global warming promotes the development of pathogenic bacteria, hence disease development on fish farms," Rodolphe Gozlan, an IRD specialist in biodiversity-health relations, explains.Aquatic bacteria are in effect temperature-sensitive. "Global warming will therefore push up mortality rates on fish farms, which is likely to mean increased antibiotic use," says Miriam Reverter, a post-doctoral student at IRD, and as the study showed, antimicrobial resistance is already a reality in several countries among those that are highly vulnerable to climate change.The study's authors raise the alarm about the consequences of inappropriate antibiotic use, for both the sustainability of aquaculture and human health. "Resistant bacteria in aquaculture can either spread or transmit their resistance genes to non-resistant bacteria that infect humans, thus causing diseases that are difficult to treat in both animals and humans," Samira Sarter, a microbiologist with CIRAD, explains.These health risks linked to antibiotic use are not restricted to aquaculture. They also apply to terrestrial farms. "Some 60% of the infectious diseases that currently affect humans are of animal origin. If a resistant bacterium or its genes were to be transmitted to humans, and existing antibiotics were ineffective, we could face a steep rise in mortality rates as a result of antimicrobial resistance.""We urgently need to help producers in the global South find alternatives to treat and prevent disease on fish farms. This means encouraging research that makes use of the One Health or EcoHealth approaches, i.e. that is multi-disciplinary and multi-sector," Rodolphe Gozlan stresses. Work has shown that certain plants are highly effective for boosting disease immunity in fish. Their use on fish farms could help reduce antibiotic use. Alongside this, researchers are also working to develop more resilient aquaculture systems based on the principles of agroecology, in the aim of reducing disease rates.
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Agriculture & Food
| 2,020 |
April 20, 2020
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https://www.sciencedaily.com/releases/2020/04/200420105045.htm
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Cable bacteria can drastically reduce greenhouse gas emissions from rice cultivation
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A Danish-German research collaboration may have found a solution to the large climate impact from the world's rice production: By adding electric conductive cable bacteria to soil with rice plants, they could reduce methane emissions by more than 90%.
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Half of world´s population is nourished by rice crops, but rice cultivation is harsh to he climate. The rice fields account for five percent of global emissions of the greenhouse gas methane, which is 25 times stronger than CO2.This is because the rice plants grow in water. When the fields are flooded, the soil becomes poor in oxygen, creating the right conditions for microorganisms to produce methane. Now researchers from Aarhus University and the University of Duisburg-Essen have found that cable bacteria could be an important part of the solution. In the laboratory, they have grown rice in soil with and without cable bacteria and measured what happened."And the difference was far beyond my expectations. The pots with cable bacteria emitted 93% less methane than the pots without cable bacteria, "says Vincent Valentin Scholz, who conducted the experiments as a PhD student at the Center for Electromicrobiology (CEM) at Aarhus University.The result is published today in the scientific journal "Cable bacteria transport electrons over centimeter distances along their filaments, changing the geochemical conditions of the water-saturated soil. The cable bacteria recycle the soil's sulfur compounds, thus maintaining a large amount of sulfate in the soil. This has the consequence that the methane-producing microbes cannot maintain their activity," explains Vincent Valentin Scholz.It is already known that the rice growers can temporarily slow down the emission of methane by spreading sulfate on the rice fields. Apparently, the cable bacteria can do this for them -- and not just temporarily.This finding adds a new angle to the role of cable bacteria as ecosystem engineers. While the authors emphasize that they have only the very first laboratory observation, it is tempting to speculate that enrichment of cable bacteria by sensible management of water and soil regime could become a sustainable and convenient solution for reducing methane emissions from rice fields. But of course, it requires field studies to see how cable bacteria can thrive in rice fields.Cable bacteria were an unknown way of life until they were first identified in the Bay of Aarhus, Denmark, in 2012. They thrive on the bottom of the sea, lakes, groundwater and streams and often in large quantities. Each individual consists of thousands of cells in a centimeter-long chain surrounded by a common outer sheath with electric wires. One end is buried in the oxygen-poor sediment, the other is so close to the water that it has contact with oxygen. This allows the bacteria to use electric power to burn the food in an oxygen-free environment. The process also changes the chemical composition of the soil.
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Agriculture & Food
| 2,020 |
April 17, 2020
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https://www.sciencedaily.com/releases/2020/04/200417212909.htm
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Valorizing wastewater can improve commercial viability of biomass oil production
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Oil produced from biomass can provide a sustainable alternative to fossil fuels. But technological challenges make it difficult to scale up production and make it economically viable.
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One technology known as hydrothermal liquefaction (HTL) allows for production of biocrude oil from wet biomass such as algae, food waste, or animal manure. This process sidesteps costly drying procedures; however, it creates a wastewater byproduct that is considered an environmental hazard.A new study from the University of Illinois discusses methods to manage this wastewater, providing a possible path to commercially viable production.Jamison Watson, doctoral student in the Department of Agricultural and Biological Engineering at U of I, says the study provides a comprehensive overview of current wastewater treatment methods that can help producers and researchers going forward.HTL techniques are still in the exploratory phase. But as oil becomes more expensive and more scarce, Watson predicts that will change."People haven't really started to address engineering challenges like upscaling to a large facility. We just think we're ahead of our time," he says.Watson explains the study is a result of a collaboration among researchers working with different aspects of the technologies. Some of that work happens in the research lab of Yuanhui Zhang, professor of agricultural and biological engineering at Illinois. Zhang is Watson's advisor, and co-author of the paper."We work on producing oil from biomass such as food waste and algae through HTL. One of the byproducts of this process is the post-HTL wastewater (PHW), also called aqueous phase," Watson says. "We saw this big issue: what can we do with the wastewater? We have no way of managing it; we can't just dilute it; we can't just release it into the environment."The study provides a detailed analysis of currently available methodologies, and it describes six different approaches to treating PHW. Those include separation of chemicals, cultivation of biomass, anaerobic fermentation, bioelectrochemical systems, hydrothermal gasification, and recycling of PHW as a solvent or reactant for HTL.Some of the potential applications created through these approaches include extraction of chemicals and gases, production of electricity or hydrogen, or purifying the liquid so it is clean enough to water crops or even use as drinking water, Watson says.For each of the six methods, Watson and his collaborators describe the technology, discuss the benefits and challenges, and assess future potential, as well as feasibility of upscaling to commercial application."We want to learn which technologies show the most promise," Watson says. "So when this thermochemical technology really hits its stride in the next 10 to 20 years, people will have an idea of how we can valorize the wastewater byproduct to highlight the potential of this oil production technology."
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Agriculture & Food
| 2,020 |
April 17, 2020
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https://www.sciencedaily.com/releases/2020/04/200417114517.htm
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Relying on 'local food' is a distant dream for most of the world
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Globalisation has revolutionised food production and consumption in recent decades and cultivation has become more efficient As a result, diets have diversified and food availability has increased in various parts of the globe. However, it has also led to a situation where the majority of the world population live in countries that are dependent on, at least partially, imported food. This can intensify vulnerabilities during any kind of global crisis, such as the current COVID-19 pandemic, as global food supply chains are disrupted.
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Aalto University dissertation researcher, Pekka Kinnunen, says: "There are big differences between different areas and the local foliage. For example, in Europe and North America, temperate crops, such as wheat, can be obtained mostly within a radius of 500 kilometres. In comparison, the global average is about 3,800 kilometres."The recent study, published in It was shown that 27% of the world's population could get their temperate cereal grains within a radius of fewer than 100 kilometres. The share was 22% for tropical cereals, 28% for rice and 27% for pulses. In the case of maize and tropical roots, the proportion was only 11-16%, which Kinnunen says displays the difficulty of relying solely on local resources."We defined foodsheds as areas within which food production could be self-sufficient. In addition to food production and demand, food fences describe the impact of transport infrastructure on where food could be obtained," Kinnunen explains.The study also showed that foodsheds are mostly relatively compact areas for individual crops. When crops are looked at as a whole, foodsheds formed larger areas, spanning the globe. This indicates that the diversity of our current diets creates global, complex dependencies.According to Associate professor Matti Kummu, who was also involved in the study, the results clearly show that local production alone cannot meet the demand for food; at least not with current production methods and consumption habits. Increasing the share of effectively managed domestic production would probably reduce both food waste and greenhouse gas emissions. However, at the same time, it could lead to new problems such as water pollution and water scarcity in very densely populated areas, as well as vulnerabilities during such occurrences as poor harvests or large-scale migration."The ongoing COVID-19 epidemic emphasises the importance of self-sufficiency and local food production. It would be important also to assess the risks that dependence on imported agricultural inputs such as animal feed proteins, fertilisers and energy, might cause," says Kummu.Kummu and Kinnunen work in Water and Development Research Group at Aalto School of Engineering. The group focuses on the sustainability of water resources, especially in the context of water used in food production. Read more:
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Agriculture & Food
| 2,020 |
April 16, 2020
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https://www.sciencedaily.com/releases/2020/04/200416114539.htm
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Returning land to nature with high-yield farming
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The expansion of farmlands to meet the growing food demand of the world's ever expanding population places a heavy burden on natural ecosystems. A new IIASA study however shows that about half the land currently needed to grow food crops could be spared if attainable crop yields were achieved globally and crops were grown where they are most productive.
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The land sparing debate, which was sparked around 2005 by conservation biologists, recognized that there is usually a limit to the extent to which farmland can be made 'wildlife friendly' without compromising yields, while most threatened species only profit from the sparing or restoration of their natural habitats. Interest in this topic recently gained new momentum through the Half Earth project, which aims to return half the area of land currently being used for other purposes to natural land cover to restrict biodiversity loss and address other impacts of land use such as greenhouse gas emissions.According to the authors of the study published in "The main questions we wanted to address were how much cropland could be spared if attainable crop yields were achieved globally and crops were grown where they are most productive. In addition, we wanted to determine what the implications would be for other factors related to the agricultural sector, including fertilizer and irrigation water requirements, greenhouse gas emissions, carbon sequestration potential, and wildlife habitat available for threatened species," explains study lead author Christian Folberth, a researcher in the IIASA Ecosystems Services and Management Program.The study results indicate that with high nutrient inputs and reallocation of crops on present cropland, only about half the present cropland would be required to produce the same amounts of major crops. The other half could then in principle be used to restore natural habitats or other landscape elements. The findings also show that land use is currently somewhat inefficient and not primarily due to the upper limits to crop yields as determined by climate in many parts of the world, rather, it is strongly subject to management decisions.It is difficult to say exactly how much biodiversity is impacted as a direct result of agricultural activities, but it is estimated to exceed safe boundaries, primarily due to habitat loss. In this regard, the researchers evaluated two scenarios: the first proposes maximum land sparing without constraints, except for the present cropland extent, while the second scenario puts forward targeted land sparing that abandons cropland in biodiversity hotspots and uniformly releases 20% of cropland globally. There were only marginal differences between the two scenarios in most aspects, except for wildlife habitat, which only increased significantly with targeted land sparing. This however still enabled reducing the cropland requirement by almost 40%.Furthermore, the researchers found that greenhouse gas emissions and irrigation water requirements are likely to decrease with a reduced area of cultivated land, while global fertilizer input requirements would remain unchanged. Spared cropland could also provide space for substantial carbon sequestration in restored natural vegetation. Yet, potentially adverse local impacts of intensive farming and land sparing such as nutrient pollution or loss of income in rural areas will need to be studied further."The results of our study can help policymakers and the wider public to benchmark results of integrated land use scenarios. It also shows that cropland expansion is not inevitable and that there is significant potential for improving present land use efficiency. If the right policies are implemented, measures such as improved production technologies can be just as effective as demand-side measures like dietary changes," says project lead and former IIASA Ecosystems Services and Management Program Director Michael Obersteiner. "However, in all cases such a process would need to be steered by policies to avoid unwanted outcomes."
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Agriculture & Food
| 2,020 |
April 16, 2020
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https://www.sciencedaily.com/releases/2020/04/200416091939.htm
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Healthier climate: Fava beans could replace soy
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Tofu, soy milk and veggie mince. More and more Danes are opting to supplement or completely replace their consumption of animal-based proteins with plant-based proteins. Climate considerations are part of their reasoning.
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We often use soy-based protein when experimenting with vegetarian cooking. But, new research from the University of Copenhagen's Department of Food Science demonstrates that fava beans hold great promise as a non-soy source of plant protein. Moreover, favas are a better alternative for the environment:"Many consumers are crying out for alternatives to soy, a crop that places great strain on the environment. This prompted us to find a method of processing fava beans in such a way that allows us to produce a concentrated protein powder. One of the advantages of fava beans is that they can be grown here, locally in Denmark. This is excellent news for the climate," explains Iben Lykke Petersen, an assistant professor at the University of Copenhagen's Department of Food Science, and one of the researchers behind the new study published in the journal Fava beans are better suited for climate considerations because they can be cultivated locally, unlike soybeans, which are primarily grown in the United States and South America -- and then exported to Denmark.Moreover, numerous farms in Brazil and Paraguay have cleared large tracts of forest to create space for soybean fields. This has had severely negative consequences for wildlife, biodiversity and CO2 emissions."Another important factor is that, unlike fava beans, lots of soy is genetically modified to be able to tolerate Roundup, an herbicide. Within this context, many consumers are critical of soy's environmental consequences," explains Iben Lykke Petersen.To find an alternative to environmentally taxing soybean, the study's researchers tested various crops, looking for those with the greatest potential as a protein powder, while also being able to be grown locally. Here, fava beans outperformed lentils, amaranth, buckwheat and quinoa.Using an incredibly unique method known as 'wet fractionation', the researchers succeeded in concentrating fava bean protein and removing substances that would otherwise inhibit the digestion of the protein. This allows nutritious fava bean proteins to be more readily absorbed when consumed."Wet fractionation is accomplished by milling beans into a flour, and then adding water and blending the mixture into a soup. Thereafter, it becomes easier for us to sort out the less beneficial substances and produce an optimized product," explains Iben Lykke Petersen. She adds:"Our results demonstrate that this method significantly increases protein content. Furthermore, through our tests, we can see that this protein is nearly as readily digested as when we break down protein from animal products, such meat and eggs."Competitive color, taste and texture.The content and nutritional quality of a protein is one thing. Taste is something else! Here too, fava beans can compete with soy and other plant-based protein alternatives. Iben Lykke Petersen explains that when fava beans are processed correctly, their proteins retain their naturally bright colour, along with a neutral taste and good texture."Manufacturers prefer a product that is tasteless, has a neutral color and a firm texture. Fava beans check each these boxes, unlike peas, which often have a very bitter aftertaste," she concludes.Fava beans are grown primarily in the Middle East, China and Ethiopia, but are already available in Danish supermarkets and health food stores.
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Agriculture & Food
| 2,020 |
April 15, 2020
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https://www.sciencedaily.com/releases/2020/04/200415133512.htm
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Nanosensor can alert a smartphone when plants are stressed
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MIT engineers have developed a way to closely track how plants respond to stresses such as injury, infection, and light damage, using sensors made of carbon nanotubes. These sensors can be embedded in plant leaves, where they report on hydrogen peroxide signaling waves.
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Plants use hydrogen peroxide to communicate within their leaves, sending out a distress signal that stimulates leaf cells to produce compounds that will help them repair damage or fend off predators such as insects. The new sensors can use these hydrogen peroxide signals to distinguish between different types of stress, as well as between different species of plants."Plants have a very sophisticated form of internal communication, which we can now observe for the first time. That means that in real-time, we can see a living plant's response, communicating the specific type of stress that it's experiencing," says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT.This kind of sensor could be used to study how plants respond to different types of stress, potentially helping agricultural scientists develop new strategies to improve crop yields. The researchers demonstrated their approach in eight different plant species, including spinach, strawberry plants, and arugula, and they believe it could work in many more.Strano is the senior author of the study, which appears today in Over the past several years, Strano's lab has been exploring the potential for engineering "nanobionic plants" -- plants that incorporate nanomaterials that give the plants new functions, such as emitting light or detecting water shortages. In the new study, he set out to incorporate sensors that would report back on the plants' health status.Strano had previously developed carbon nanotube sensors that can detect various molecules, including hydrogen peroxide. About three years ago, Lew began working on trying to incorporate these sensors into plant leaves. Studies in Arabidopsis thaliana, often used for molecular studies of plants, had suggested that plants might use hydrogen peroxide as a signaling molecule, but its exact role was unclear.Lew used a method called lipid exchange envelope penetration (LEEP) to incorporate the sensors into plant leaves. LEEP, which Strano's lab developed several years ago, allows for the design of nanoparticles that can penetrate plant cell membranes. As Lew was working on embedding the carbon nanotube sensors, he made a serendipitous discovery."I was training myself to get familiarized with the technique, and in the process of the training I accidentally inflicted a wound on the plant. Then I saw this evolution of the hydrogen peroxide signal," he says.He saw that after a leaf was injured, hydrogen peroxide was released from the wound site and generated a wave that spread along the leaf, similar to the way that neurons transmit electrical impulses in our brains. As a plant cell releases hydrogen peroxide, it triggers calcium release within adjacent cells, which stimulates those cells to release more hydrogen peroxide."Like dominos successively falling, this makes a wave that can propagate much further than a hydrogen peroxide puff alone would," Strano says. "The wave itself is powered by the cells that receive and propagate it."This flood of hydrogen peroxide stimulates plant cells to produce molecules called secondary metabolites, such as flavonoids or carotenoids, which help them to repair the damage. Some plants also produce other secondary metabolites that can be secreted to fend off predators. These metabolites are often the source of the food flavors that we desire in our edible plants, and they are only produced under stress.A key advantage of the new sensing technique is that it can be used in many different plant species. Traditionally, plant biologists have done much of their molecular biology research in certain plants that are amenable to genetic manipulation, including Arabidopsis thaliana and tobacco plants. However, the new MIT approach is applicable to potentially any plant."In this study, we were able to quickly compare eight plant species, and you would not be able to do that with the old tools," Strano says.The researchers tested strawberry plants, spinach, arugula, lettuce, watercress, and sorrel, and found that different species appear to produce different waveforms -- the distinctive shape produced by mapping the concentration of hydrogen peroxide over time. They hypothesize that each plant's response is related to its ability to counteract the damage. Each species also appears to respond differently to different types of stress, including mechanical injury, infection, and heat or light damage."This waveform holds a lot of information for each species, and even more exciting is that the type of stress on a given plant is encoded in this waveform," Strano says. "You can look at the real time response that a plant experiences in almost any new environment."The near-infrared fluorescence produced by the sensors can be imaged using a small infrared camera connected to a Raspberry Pi, a $35 credit-card-sized computer similar to the computer inside a smartphone. "Very inexpensive instrumentation can be used to capture the signal," Strano says.Applications for this technology include screening different species of plants for their ability to resist mechanical damage, light, heat, and other forms of stress, Strano says. It could also be used to study how different species respond to pathogens, such as the bacteria that cause citrus greening and the fungus that causes coffee rust."One of the things I'm interested in doing is understanding why some types of plants exhibit certain immunity to these pathogens and others don't," he says.Strano and his colleagues in the Disruptive and Sustainable Technology for Agricultural Precision interdisciplinary research group at the MIT-Singapore Alliance for Research and Technology (SMART), MIT's research enterprise in Singapore, are also interested in studying is how plants respond to different growing conditions in urban farms.One problem they hope to address is shade avoidance, which is seen in many species of plants when they are grown at high density. Such plants turn on a stress response that diverts their resources into growing taller, instead of putting energy into producing crops. This lowers the overall crop yield, so agricultural researchers are interested in engineering plants so that don't turn on that response."Our sensor allows us to intercept that stress signal and to understand exactly the conditions and the mechanism that are happening upstream and downstream in the plant that gives rise to the shade avoidance," Strano says.The research was funded by the National Research Foundation of Singapore, the Singapore Agency for Science, Technology, and Research (A*STAR), and the U.S. Department of Energy Computational Science Graduate Fellowship Program.
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Agriculture & Food
| 2,020 |
April 15, 2020
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https://www.sciencedaily.com/releases/2020/04/200415084310.htm
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Breeding a hardier, more nutritious wheat
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Some new crop varieties are bred to be more nutritious. Others are more resilient, bred to tolerate harsher environmental conditions.
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In a new study, researchers report a variety of wheat that combines enhanced nutrition with increased resilience. The researchers also tested a breeding method that could reduce costs and save time compared to traditional methods.The newly developed wheat variety contains higher levels of a naturally occurring carbohydrate, called fructans."Wheat with increased fructan levels can be more climate-resilient in certain situations," says Lynn Veenstra, a researcher at Cornell University. "These situations include high salinity or cold temperatures."Fructans are long chains of the sugar fructose. Unlike the fructose present in foods, such as high-fructose corn syrup, fructans cannot be digested by humans. This makes fructans a good source of soluble fiber.Previous research has shown that consuming foods with higher fructan levels could also promote healthy gut bacteria.In the US, a large portion of daily fructan intake comes from wheat products, such as bread. That makes developing high-fructan wheat important.There's yet another advantage to using high-fructan wheat. "We wouldn't have to supplement wheat products with fructans or fiber from other sources," says Veenstra. "This wheat would already contain higher levels of fructans."But breeding high-fructan wheat can be time-consuming and expensive. "The development of nutritionally improved wheat varieties often requires extensive resources," says Veenstra.Typically, a process called phenotyping takes the most time. Phenotyping is the measurement of crop characteristics -- like fructan levels or yield.Phenotyping allows plant breeders to compare new and existing varieties of crops. For example, they can test if newer varieties have higher or lower fructan levels than existing crops. At the same time, they need to make sure other crop features -- like yield or disease resistance -- haven't been reduced.A relatively new breeding method can expedite the development of new crop varieties. Veenstra and colleagues tested variations of this method, called genomic selection.Genomic selection uses a relatively small 'training' set of individual plants. Researchers combine phenotyping and genetic data from this training set of plants. Then they use these data to train a statistical model.Once trained, the statistical model can predict plant characteristics -- like fructan levels -- based solely on genetics."This allows crop breeding without needing to collect data on observed characteristics," says Veenstra.Genomic selection saves time and resources in two ways. First, the training set of plants is relatively small. That allows phenotyping to be concluded quickly. Second, genetic testing can often be much quicker than measuring crop characteristics.Ultimately, genomic selection can allow breeders to save both cost and time during the breeding process.There are some caveats to using genomic selection, though. Inbreeding can happen, for instance, which can reduce crop diversity. Reduced diversity can make crops susceptible to diseases.So Veenstra and her colleagues tested two different modes of genomic selection. They found that one method led to wheat with higher fructans while maintaining genomic diversity."I think this is the most important finding of this study," says Veenstra. "Genomic selection can be used for nutritional breeding."Researchers still need to know more about the fructans in the new wheat variety. "We also want to determine how stable these fructans are during food processing," says Veenstra.For example, yeast degrades different fructans at different rates. That would impact how much fructan ends up in a loaf of bread."I believe both wheat growers and consumers stand to benefit from high-fructan wheat," says Veenstra. "For wheat growers, high-fructan varieties have the potential to withstand climatic stress. For consumers, high-fructan wheat products may have positive impacts on gut-health."
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Agriculture & Food
| 2,020 |
April 14, 2020
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https://www.sciencedaily.com/releases/2020/04/200414173714.htm
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Turned-down temperatures boost crops' penchant for production
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Drought and heat put stress on plants and reduce grain yield. For some farmers, irrigation is the answer. Many of us assume the practice boosts crop yields by delivering soil water, but it turns out irrigation's cooling effect on crops is important in its own right.
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In a recent U.S.-based study, a research team led by University of Illinois scientists discovered 16% of the yield increase from irrigation is attributable to cooling alone."This study highlights the non-negligible contribution of cooling to the yield benefits of irrigation. Such an effect may become more important in the future with continued warming and more frequent droughts," says Yan Li, lead author on the Irrigation cools crops through the combined effects of transpiration -- water loss through tiny holes in leaves called stomata -- and evaporation from soil. Transpiration can only occur when there is a sufficient soil water supply; when roots sense dry soil, plants close their stomata to prevent water loss. When this happens for long enough, plants heat up and suffer drought stress, sometimes leading to yield reductionsWith soil water supply and temperature so inextricably linked, the researchers had to develop an innovative approach to separate out the cooling effect on yield. The team analyzed satellite-derived crop temperature and biomass data, irrigation maps, and county-level corn yield in Nebraska between 2003 and 2016. By comparing irrigated and rainfed sites, they found irrigation bumped yield by 81%, of which 16% was attributable to cooling and 84% to water supply. Irrigation also lowered July land surface temperatures by 1.63 degrees Celsius relative to rainfed sites."Crops grown in the irrigated part of the U.S. Corn Belt, mostly in Nebraska and some other western states in the Midwest, all feel the cooling benefit," says Kaiyu Guan, principal investigator of the project and Blue Waters professor in the Department of Natural Resources and Environmental Sciences and the National Center for Supercomputing Applications at Illinois. "Crops feel happier when they are cooler."According to Li, teasing out irrigation's dual contributions to yield will allow better yield forecasting into the future. The cooling effect has largely been neglected in previous crop models."When yield forecasters develop their models, they should realize cooling is another important benefit for irrigated cropland, and they need to take that into account. Otherwise, they may underestimate the irrigation benefit on yield," he says.Guan adds, "This matters not only for currently irrigated cropland like Nebraska. Under a warming climate, we envision that crops will need more water to grow the same biomass, and parts of the Corn Belt that are currently rainfed, like Iowa and Illinois, may also need irrigation."
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Agriculture & Food
| 2,020 |
April 13, 2020
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https://www.sciencedaily.com/releases/2020/04/200413115908.htm
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Foxglove plants produce compounds used in heart medicine; can science do it better?
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Foxglove plants, found in many gardens, are known for the showers of bell-shaped flowers they produce.
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But plants belonging to this genus, Digitalis, also harbor a less visible asset: Chemicals called cardiac glycosides, which have been recorded to treat heart failure since the 1780s, says University at Buffalo biologist Zhen Wang.Wang's research investigates how foxgloves create these medicinal compounds, with an eye toward improving the process. Farming foxgloves is time-consuming and labor-intensive, and Wang hopes to change that.Specifically, her lab is investigating the chemical processes the plants use to create cardiac glycosides: what steps are taken, what genes are turned on, and what enzymes are deployed."The reason why plants make so many natural products with medicinal properties is because they are also fighting diseases," says Wang, PhD, assistant professor of biological sciences in the UB College of Arts and Sciences. "Plants aren't like animals. They can't run away when stresses come, so they cope with this by becoming the most extraordinary chemists on the planet."And yet, "How plants synthesize many natural products is largely unknown," Wang says. "I want to understand how we can harness the power of nature to make the process of producing medicinal compounds more efficient and sustainable. Foxgloves make these powerful compounds, but it takes two years to do so, and they don't make them in a very large quantity. How can we improve this process?"Wang's team recently published a pair of papers detailing the characteristics of cardiac glycosides in two foxglove species: Digitalis purpurea, a showy purple flower found in many gardens; and Digitalis lanata, which is grown for medicinal purposes."This kind of study is important because we first have to know the accurate structure of natural compounds before we can explore their medicinal effects," Wang says.The first paper, published online in January in the "When we looked at the cardiac glycosides in each of them, we found drastic differences," Wang says. "In the industrial strain that's grown for medicine, you see much higher amounts of cardiac glycosides, with much more diversity. I think this just highlights the adaptation of plants and how versatile they are as chemists."Both studies included contributions from researchers in the UB Department of Chemistry.Digitalis lanata is cultivated for medicine because it makes a cardiac glycoside called digoxin. This compound is toxic in large quantities, but it's prescribed sparingly, in small doses, to treat heart failure and certain heart rhythm abnormalities.Current methods for producing digoxin are cumbersome: Because each foxglove plant makes only a little bit of the chemical, farmers must grow the crop in huge quantities, Wang says. That uses up a lot of agricultural land. The wait time is also long."It takes two years, from the time you plant the seed to the time the leaves are ready to harvest, and then you have to dry it in the silo," Wang says. "Then, the plant is crushed into powder, and the compound is extracted and purified using chemical processes."If Wang's team can figure out, step-by-step, how foxgloves make cardiac glycosides, scientists could leverage that information to explore a variety of improvements.Biologists could engineer fast-growing microbes, such as yeast or harmless strains of bacteria, to produce cardiac glycosides more quickly. Plant scientists could genetically engineer foxgloves to make larger amounts of digoxin, which would increase the efficiency of farms and free up land for other useful crops.Medicinal chemists could also work to develop new drugs that are similar to digoxin but safer."We can learn from nature," Wang says. "We can study all of the available compounds that are found in the plants and then come up with our own design of compounds that are safer and more effective. That's why I think it's important to not just focus on the current drug digoxin, but to expand our focus to all the compounds in the same class, the cardiac glycosides."
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Agriculture & Food
| 2,020 |
April 13, 2020
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https://www.sciencedaily.com/releases/2020/04/200413103534.htm
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Plants control microbiome diversity inside leaves to promote health
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In a new study, published in the journal
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This is the first study to show a causal relationship between plant health and assembly of the microbial community in the phyllosphere -- the total above-ground portions of plants. The work suggests that organisms, from plants to animals, may share a similar strategy to control their microbiomes.Microbiome studies are a hot topic in human health science. When scientists mention that human 'gut bacteria' should be well balanced, they refer to the gut microbiome, the genetic material of all the microbes living in human digestive systems."The field of large-scale plant microbiome study is only about a decade old," said Sheng Yang He, lead co-author of the study, a member of the MSU-DOE Plant Research Laboratory and a Howard Hughes Medical Institute Investigator. "We want to know if plants need a properly assembled phyllosphere microbiome."In nature, plants are bombarded by zillions of microbes," said He, a University Distinguished Professor who holds joint appointments in the Department of Plant Biology and the Department of Microbiology and Molecular Genetics in the MSU College of Natural Science. "If everything is allowed to grow in the plants, it would probably be a mess. We want to know if the numbers and types of microbes matter, if there is a perfect composition of microbes. If so, do plants have a genetic system to host and nurture the right microbiome?"It seems plants do. The newly discovered mechanism involves two genetic networks. One involves the plant immune system and the other controls hydration levels inside leaves. Both networks work together to select which microbes survive inside of plant leaves."When we remove both networks from a plant, the microbiome composition inside the leaves changes," He said. "The numbers and mix of bacteria types are abnormal, and our team sees symptoms of tissue damage in plants.""The symptoms are conceptually like those associated with inflammatory bowel disease in humans," he said. "This is probably because the genes involved are ancient, in evolutionary terms. These genes are found in most plants, while some even have similarities to those involved in animal immunity. "According to the scientists in the He lab, this may be the first time dysbiosis-associated sickness is formally described in the plant kingdom. The fact it seems conceptually similar to human health suggests a fundamental process in life.The reason it is difficult to find causality in microbiome studies is because it is practically impossible to cut through the noise of zillions of microbes.The He lab has worked around this problem by developing a germ-free growth chamber they call the gnotobiotic system -- an environment for rearing organisms in which all the microorganisms are either known or excluded."Very few people have grown a sterile plant in sterile, organic-rich material," He said. "Our system uses a peat-based soil-like substrate, basically greenhouse potting soil. We use heat and pressure to kill all the germs in the soil, and the plants can grow under this germ-free condition."Researchers can then introduce microbes in a controlled fashion, into this environment."You can add one, two, or even a community of bacteria," He said. "In our study, we extracted a community of bacteria from dysbiotic, or sick, plants and introduced them to our healthy plants, and vice-versa. We found that both the microbiome composition and the plant genetic systems are required for plant health."For example, a plant with defective genetics could not take advantage of a microbiome transplanted from a healthy plant. The microbiome slowly reverted to the state that caused sickness.On the other end, a healthy plant exposed to a sick plant's microbiome also suffered. Although it had the genetic tools to select the right microbes, microbe availability was limited and abnormal. The plant couldn't fix the situation.It turns out that increased microbiome diversity correlates with plant health. Somehow, plant genes are gatekeepers that encourage this diversity.The sick plants in the study had 100 times more microbes in a leaf, compared to a healthy plant. But the population was less diverse. To figure out why, the scientists did thousands of one-on-one bacteria face-offs to tease out which strains were aggressive.In the sick plants, proteobacteria strains -- many of which are harmful to plants -- jumped from two-thirds the composition of a healthy microbiome to 96% in the abnormal population. Fermicutes strains, many which may be helpful to plants, went down in numbers."Perhaps, when the population of microbiome is abnormally higher in that sick plant, the microbes are physically too close to each other," He said. "Suddenly, they fight over resources, and the aggressive -- in this case harmful -- ones unfortunately win. Healthy plants seem to prevent this takeover from happening."The study is yet another example of how diversity is important to support healthy living systems. Each type of microbe might impart different benefits to plants, such as increased immunity, stress tolerance or nutrient absorption.Scientists such as He want to be able to manipulate the plant genetic system to reconfigure the plant microbiome. Plants could become more efficient at selecting their microbial partners and experience improved plant health, resilience, and productivity."Our field is still young," He said. "Microbiome research tends to focus on human gut bacteria. But many more bacteria live on plant leaves, the lungs of our planet. It would be wonderful to understand how microbes impact the health of the phyllosphere in natural ecosystems and crop fields."
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Agriculture & Food
| 2,020 |
April 10, 2020
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https://www.sciencedaily.com/releases/2020/04/200410162420.htm
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New tool to combat major wheat disease
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Agricultural Research Service (ARS) scientists and their colleagues have discovered a gene that can be used to develop varieties of wheat that will be more resistant to Fusarium Head Blight (FHB), a disease that is a major threat both overseas and to the nation's $10 billion annual wheat crop.
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A paper reporting the discovery and the cloning of the gene, known as Fhb7, was published today in the journal The discovery is a major advance in addressing a significant threat to the world's wheat supply. FHB, also known as "scab," is caused by a fungal pathogen, Fusarium graminearum, and results in significant losses in the United States, China, Canada, Europe, and many other countries. It also attacks barley and oats.When the pathogen grows unchecked in infected grains, it releases mycotoxins that can induce vomiting in humans, as well as weight loss in livestock when they refuse to eat the grains.The prevalence and severity of FHB outbreaks also could potentially be exacerbated by climate change and varying weather conditions, and by an increasing trend toward more corn production and no-till farming, which both may be increasing the prevalence of the pathogen in fields. Growers often must use fungicides to reduce FHB damage.The researchers found that the gene effectively reduces FHB by detoxifying the mycotoxins secreted by the pathogen. The gene also confers resistance to crown rot, a wheat disease caused by a related pathogen.The researchers originally identified the gene in Thinopyrum wheatgrass, a wild relative of wheat that has been previously used to develop varieties of wheat with beneficial traits, such as rust resistance and drought tolerance. They cloned the gene and introduced it into seven wheat cultivars with different genetic profiles to study its effects on plants grown under field conditions.The results showed that the gene not only conferred resistance to scab in the new plants, but it also had no negative effects on yield or other significant traits.The study sheds new light on the molecular mechanisms that can make wheat, as well as barley and oats, resistant to the pathogen that causes FHB. New varieties of wheat with better FHB resistance using Fhb7 are expected to be available in a few years, the researchers say.
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Agriculture & Food
| 2,020 |
April 9, 2020
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https://www.sciencedaily.com/releases/2020/04/200409105407.htm
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Fungus application thwarts major soybean pest
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The soybean cyst nematode sucks the nutrients out of soybean roots, causing more than $1 billion in soybean yield losses in the U.S. each year. A new study finds that one type of fungi can cut the nematodes' reproductive success by more than half.
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The researchers report their findings in the journal "Soybean cyst nematodes survive in the soil as eggs in cysts," said Glen Hartman, a researcher for the U.S. Department of Agriculture's Agricultural Research Service in the department of crop sciences at the University of Illinois at Urbana-Champaign. Hartman led the new research with graduate student Michelle Pawlowski. "The eggs hatch at the start of the growing season, and the juveniles penetrate root tissue and migrate into the plant's vascular system. The females find a feeding site and stay there for the rest of their lives. They take nutrients away from the soybean plant, which reduces plant productivity."Previous studies have found that fungi in the soil that form mutually beneficial relationships with soybeans and other plants can influence the success of plant parasitic nematodes, including SCN. But the effectiveness of using these "arbuscular mycorrhizal fungi" to thwart plant parasitic fungi varies from study to study, making growers reluctant to embrace this as a method of control, Hartman said."In this study, we focused on five different species of arbuscular mycorrhizal fungi to see if they differed in their ability to protect soybeans against SCN," Pawlowski said.The researchers inoculated young soybean plants with fungi and SCN in greenhouse experiments. By the end of the experiment, all five fungal species had reduced the number of SCN cysts in the roots. The lowest number of cysts occurred on plants inoculated with the fungus "Each cyst may contain hundreds of nematode eggs," Hartman said.Further experiments with "We found that as early as seven days after inoculation, roots that were inoculated with "To see if this interaction and suppression might occur even earlier, we incubated SCN eggs in sterile water alone, with fungal spores or with exudates of the fungal spores. These exudates are microbes and molecules secreted by the spores," she said.This experiment revealed that the fungal spores and their exudates undermine nematode egg hatching, she said."If we can find out what function or compound from the fungi is suppressing egg hatching, that could potentially be a useful nematicide," Pawlowski said.
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Agriculture & Food
| 2,020 |
April 9, 2020
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https://www.sciencedaily.com/releases/2020/04/200409093943.htm
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Hormone produced in starved leaves stimulates roots to take up nitrogen
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Nagoya University researchers have found that in response to the nitrogen demand of leaves, plants produce a hormone that travels from the leaves to the roots to stimulate the uptake of nitrogen from the soil. This hormone is produced in the leaves when they run short of nitrogen, and acts as a signal that regulates the demand and supply of nitrogen between the plant's shoot and the root. The findings have recently been published online in the journal
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Nitrogen is an essential nutrient for plant growth and is very important for crop production. However, often too much nitrogen fertilizer is used, leading to contamination of the environment and rising food prices. What if plants could be made to regulate their own intake of nitrogen more effectively?Nagoya University researchers have found the key to doing this. "By enhancing the pathway of this hormone, plants could be able to absorb nitrogen nutrients more efficiently, which may eventually minimize the use of fertilizers," says Professor Yoshikatsu Matsubayashi of the Graduate School of Science at Nagoya University.Plant roots take up nitrogen nutrients in the form of nitrate from the soil -- how much nitrogen a plant needs depends on the shoot growth stage. The larger and more numerous the leaves and stems become, the more nitrogen a plant needs.The research team studied how plant roots sense nitrogen demand in the shoots. A previous study using a plant called In the new study, Prof. Matsubayashi and colleagues also focused on these hormones in In contrast, the researchers demonstrated that on plants where the CEPDL2 peptide had been destroyed, leaves were still small in the later growth period when the shoot requires a lot of nitrogen. "This means the plant cannot grow properly without this peptide, showing that the CEPDL2 peptide is the signal that regulates the balance of demand and supply between leaves and roots," Prof. Matsubayashi says. "Our findings highlight one extraordinary way in which plants sense and adapt to changing conditions."
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Agriculture & Food
| 2,020 |
April 8, 2020
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https://www.sciencedaily.com/releases/2020/04/200408113256.htm
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Revolutionary new method for dating pottery sheds new light on prehistoric past
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A team at the University of Bristol has developed a new method of dating pottery which is allowing archaeologists to date prehistoric finds from across the world with remarkable accuracy.
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The exciting new method, reported in detail today in the journal Archaeological pottery has been used to date archaeological sites for more than a century, and from the Roman period onwards can offer quite precise dating. But further back in time, for example at the prehistoric sites of the earliest Neolithic farmers, accurate dating becomes more difficult because the kinds of pottery are often less distinctive and there are no coins or historical records to give context.This is where radiocarbon dating, also known as 14C-dating, comes to the rescue. Until now, archaeologists had to radiocarbon date bones or other organic materials buried with the pots to understand their age.But the best and most accurate way to date pots would be to date them directly, which the University of Bristol team has now introduced by dating the fatty acids left behind from food preparation.Professor Richard Evershed from the University of Bristol's School of Chemistry led the team. He said: "Being able to directly date archaeological pots is one of the "Holy Grails" of archaeology. This new method is based on an idea I had going back more than 20 years and it is now allowing the community to better understand key archaeological sites across the world."We made several earlier attempts to get the method right, but it wasn't until we established our own radiocarbon facility in Bristol that we cracked it. There's a particular beauty in the way these new technologies came together to make this important work possible and now archaeological questions that are currently very difficult to resolve could be answered."The trick was isolating individual fat compounds from food residues, perhaps left by cooking meat or milk, protected within the pores of prehistoric cooking pots. The team brought together the latest high resolution nuclear magnetic resonance spectroscopy and mass spectrometry technologies to design a new way of isolating the fatty acids and checking they were pure enough for accurate dating.The team then had to show that the new approach gave dates as accurate as those given by materials commonly dated in archaeology, such as bones, seeds and wood. To do this the team looked at fat extracts from ancient pottery at a range of key sites in Britain, Europe and Africa with already precise dating which were up to 8,000 years old.From the famous Sweet Track site in Somerset and several sites in the Alsace region of France, to the World Heritage site of Çatalhöyük in central Turkey and the famous rock shelter site of Takarkori in Saharan Africa, the new method was proven to date sites incredibly accurately, even to within a human life span.Professor Alex Bayliss, Head of Scientific Dating at Historic England, who undertook the statistical analyses, added: "It is very difficult to overstate the importance of this advance to the archaeological community. Pottery typology is the most widely used dating technique in the discipline, and so the opportunity to place different kinds of pottery in calendar time much more securely will be of great practical significance."In London, England, the new dating method has been used on a remarkable collection of pottery found in Shoreditch, thought to be the most significant group of Early Neolithic pottery ever found in the capital. The extraordinary trove, comprising 436 fragments from at least 24 separate vessels weighing nearly 6.5 kilos in total, was discovered by archaeologists from MOLA (Museum of London Archaeology).The site appeared to date from the time when the first farmers came to Britain but accurately dating it was difficult until the Bristol team, using their new dating method on traces of milk fats extracted from the pots, showed the pottery was 5,500 years old. The team were able to date the pottery collection to a window of just 138 years, to around 3600BC.The results indicate that around 5600 years ago the area around what is now Shoreditch High Street was used by established farmers who ate cow, sheep or goat dairy products as a central part of their diet. These people were likely to have been linked to the migrant groups who were the first to introduce farming to Britain from Continental Europe around 4000 BC -- just 400 years earlier.Jon Cotton, a consultant prehistorian working for MOLA, said: "This remarkable collection helps to fill a critical gap in London's prehistory. Archaeological evidence for the period after farming arrived in Britain rarely survives in the capital, let alone still in-situ. This is the strongest evidence yet that people in the area later occupied by the city and its immediate hinterland were living a less mobile, farming-based lifestyle during the Early Neolithic period."The results from this site are a prime example of where pottery survives in circumstances that other organic materials do not, so using this revolutionary new method will unlock important information about our prehistoric past.
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Agriculture & Food
| 2,020 |
April 7, 2020
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https://www.sciencedaily.com/releases/2020/04/200407164947.htm
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How forest loss leads to spread of disease
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Viruses that jump from animals to people, like the one responsible for COVID-19, will likely become more common as people continue to transform natural habitats into agricultural land, according to a new Stanford study.
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The analysis, published in "At a time when COVID-19 is causing an unprecedented level of economic, social and health devastation, it is essential that we think critically about how human behaviors increase our interactions with disease-infected animals," said study lead author Laura Bloomfield, an MD student in the School of Medicine and a PhD candidate in the Emmett Interdisciplinary Program in Environment and Resources within Stanford's School of Earth, Energy & Environmental Sciences. "The combination of major environmental change, like deforestation, and poverty can spark the fire of a global pandemic."People have converted nearly half of the world's land into agriculture. Tropical forests have suffered the most, with some of the highest rates of agricultural conversion over the last few decades. In Africa, this has accounted for about three-quarters of recent forest loss. What remains, outside protected parks and preserves, are small islands of forest in a sea of farmland and areas where farmland intrudes into larger forested areas.In Uganda, decades of migration and the creation of farmlands outside Kibale National Park have led to a high density of people trying to support their families at the edge of forested habitats. Ordinarily, people avoid wild primates because they are well-known carriers of disease, and many are protected by Uganda's Wildlife Authority. However, continued loss of forested habitat means wild primates and humans are increasingly sharing the same spaces and vying for the same food.When people venture into forested areas for resources and when animals venture out of their habitats to raid crops, the chances increase for transmission of zoonotic -- or animal-to-human -- disease. A prime example is HIV, which is caused by a virus that jumped from wild primates to humans via infected bodily fluids."We humans go to these animals," study co-author Eric Lambin, the George and Setsuko Ishiyama Provostial Professor in Stanford's School of Earth, Energy & Environmental Sciences. "We are forcing the interaction through transformation of the land."Unlike previous studies that examined the issue from primarily an ecological standpoint, the Stanford study is the first to integrate landscape-level ecological factors with individual-level behavioral factors and weigh risks to human health.The researchers began by collecting land use survey data from small-scale farmers living near forest fragments. They combined this information with high-resolution satellite imagery from the same time period to model how landscape patterns and individual behaviors together make certain people more likely to have contact with wild animals.They found the strongest predictors of human-wild primate contact were the length of the forest boundary around people's homes and the frequency with which people ventured into these forested areas to collect small trees for construction material. Searching for these pole-like trees entails spending more time deep in primate habitats than other forest-based activities.The researchers were surprised to find some of their assumptions turned upside down. For example, small fragments of residual forest -- not larger expanses of habitat -- were most likely to be the site of human-wild primate contacts due to their shared borders with agricultural landscapes.Similarly, the researchers speculate that increasing intrusion of agriculture into forests and resulting human activities in these areas could lead to more spillover of infections from wild primates to humans worldwide.The researchers suggest that relatively small buffer zones, such as tree farms or reforestation projects, around biodiversity-rich forests could dramatically lessen the likelihood of human-wild primate interaction. Using external resources, such as national or international aid, to provide fuel and construction material or monetary supplements could also reduce pressure on people to seek out wood in forested areas."At the end of the day, land conservation and the reduction of forest fragmentation is our best bet to reduce human-wild animal interactions," said study coauthor Tyler McIntosh, a former graduate student in the Stanford Earth Systems Program now working at the Center for Western Priorities.
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Agriculture & Food
| 2,020 |
April 3, 2020
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https://www.sciencedaily.com/releases/2020/04/200403115121.htm
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An antibiotic masquerading as a natural compound in the Giant Madeiran Squill
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A previous study has shown that a type of squill growing in Madeira produces a chemical compound that may be useful as a medicinal drug. But a new study from researchers at Uppsala University has shown that this is probably not true: instead, the plant had likely accumulated antibiotics from contaminated soil.
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All chemical compounds in nature are built through biosynthesis, a process where plants, animals and microorganisms produce complex compounds from simpler structures. Some of these are produced with the goal of protecting the organism, e.g. the toxic compounds produced by plants to poison herbivores. The fields of pharmacognosy and natural products chemistry are focussed on taking these compounds from nature and repurposing them for use in human medicine.Today, we know quite a lot about biosynthesis within different organisms. Using this knowledge, we can even predict the kinds of chemical compounds that we expect to find within nature -- and the ones we do not.This knowledge led Luke Robertson, postdoctoral fellow working between the Department of Ecology and Genetics and the Department of Medicinal Chemistry, to question the proposed structure of a chemical compound discovered within the Madeiran Squill (Scilla madeirensis, Asparagaceae). A previous study had reported that a compound produced by the plant might be useful for the treatment of prostate hyperplasia. But the structure of the compound looked strange: it did not fit with any known biosynthetic pathway. Closer examination led Robertson to the conclusion that the researchers had not only misidentified the chemical structure -- but that they had found a substance that was not produced by the plant at all. They had discovered a synthetic antibiotic: sulfadiazine."The tools we use to identify the structures of organic compounds can be complex; we don't just put data into a computer and it then spits out a chemical structure back at us. It's like solving a riddle -- and two people might have different answers to the same riddle" said Luke Robertson.But where did the sulfadiazine come from? While the compound was clearly isolated from within the plant, we know that sulfadiazine is synthetic; that is, produced only by humans. The only reasonable explanation, according to Robertson, is that the drug had contaminated the plant and the surrounding area through polluted fertilizer. Sulfadiazine is widely used within the livestock industry and is known to be spread throughout the environment via animal manure. The compound then builds up within soil and is later accumulated within plants."It is incredibly important that we identify chemical structures correctly. Drug companies stand to lose millions by discovering a compound with potential to be used as a human drug, but then patenting the incorrect chemical structure. If another company figures this out, they can effectively 'steal' the compounds patent."
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Agriculture & Food
| 2,020 |
April 3, 2020
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https://www.sciencedaily.com/releases/2020/04/200403115111.htm
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Plant root hairs key to reducing soil erosion
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The tiny hairs found on plant roots play a pivotal role in helping reduce soil erosion, a new study has found. The research, led by the University of Bristol and published in
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Soil erosion can have a devastating impact across the globe and a serious threat for modern agriculture. The increased demand for agriculture has led to forests and natural grasslands being converted to farm fields and pastures.However, many of the plants grown, such as coffee, cotton and palm oil, can significantly increase soil erosion beyond the soil's ability to maintain and renovate. It can also lead to increased pollution and sedimentation in streams and rivers or, because these areas are often less able to hold onto water, can worsen flooding. This problem is particularly urgent considering the ever-expanding human population and climate change.Researchers from the Universities of Bristol and Exeter have revealed the crucial function the microscopic roots hairs play in binding and reinforcing soil.While the larger-scale root properties such as diameter, length and surface area have been extensively studied to understand their role in preventing soil erosion, the effect that micro-scale properties, such as root hairs, has is less well documented.The research team looked at how wild plants Arabidopsis thaliana, which produced root hairs, compared with an almost identical Arabidopsis with the same root hair structure in reducing soil erosion.They found that, when planted in sufficient density, plants with root hairs reduced soil loss almost completely -- while otherwise identical plants without hairs could not stem the flow of erosion.Three methods were used to explore the soil retention benefits of root hairs. First, the samples were placed in a sterile gel, in a petri dish, and then subjected to increasing centrifugal force. The study found that the hairless seedlings were easier to remove from the gel compared to seedlings abundant with root hairs.Second, the study found that root hairs were also shown to stabilise the plant in the soil, as they increased the force needed to uproot the plant.Third, in the experimental landscapes laboratory at Exeter, root hairs reduced water erosion to almost zero.Professor Claire Grierson, one of the study's lead authors from Bristol's School of Biological Sciences explained: "These findings could be the key in helping to tackle soil erosion. There are three possible ways root hairs could enhance soil, either the soil might bind directly to root hair surfaces, root hairs might release material that reinforces soil, or root hairs might release material that is processed by microbes into something that can reinforce soil."We hope our knowledge about the properties of plants that minimise soil erosion will allow the creation and selection of best-suited agricultural plants."Professor Quine, an expert in Earth System Science at the University of Exeter, added: "This exciting, truly interdisciplinary project across biology, maths, engineering and environmental science has given us invaluable new insights into the influence of microscopic root structures on the macroscopic behavior of soils."I was amazed at the difference that root density made in reducing soil erosion to almost zero, when root density was high, whereas soil loss was still significant when roots at the same density had no hairs."We are excited to explore how the hairs exert this extraordinary influence."The team are now working to distinguish between these hypotheses and identify the molecules involved.
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Agriculture & Food
| 2,020 |
March 31, 2020
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https://www.sciencedaily.com/releases/2020/03/200331130108.htm
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'Tequila' powered biofuels more efficient than corn or sugar
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The agave plant used to make tequila could be established in semi-arid Australia as an environmentally friendly solution to Australia's transport fuel shortage, a team of researchers at the University of Sydney, University of Exeter and University of Adelaide has found.
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The efficient, low-water process could also help produce ethanol for hand sanitiser, which is in high demand during the COVID-19 pandemic.In an article published this week in the The agave plant is now being grown as a biofuel source on the Atherton Tablelands in Far North Queensland by MSF Sugar, and it promises some significant advantages over existing sources of bioethanol such as sugarcane and corn, Associate Professor Tan said."Agave is an environmentally friendly crop that we can grow to produce ethanol-based fuels and healthcare products," said Associate Professor Tan from the Sydney Institute of Agriculture."It can grow in semi-arid areas without irrigation; and it does not compete with food crops or put demands on limited water and fertiliser supplies. Agave is heat and drought tolerant and can survive Australia's hot summers."Associate Professor Tan assembled the research team and led its economic analysis.Lead author Dr Xiaoyu Yan from the University of Exeter, who led the lifecycle assessment, said: "Our analysis highlights the possibilities for bioethanol production from agave grown in semi-arid Australia, causing minimum pressure on food production and water resources."The results suggest that bioethanol derived from agave is superior to that from corn and sugarcane in terms of water consumption and quality, greenhouse gas emissions, as well as ethanol output."This study used chemical analyses of agave from a pilot agave farm in Kalamia Estate, Queensland (near Ayr) undertaken by Dr Kendall Corbin for her University of Adelaide PhD, supervised by Professor Rachel Burton."It is fabulous that the results of my chemical analysis can be used in both an economic and environmental footprint study and have real-world applications," Dr Corbin said."The economic analysis suggests that a first generation of bioethanol production from agave is currently not commercially viable without government support, given the recent collapse in the world oil price," Associate Professor Tan said. "However, this may change with the emerging demand for new ethanol-based healthcare products, such as hand sanitisers.""This is the first comprehensive lifecycle assessment and economic analysis of bioethanol produced from a five-year agave field experiment in north Queensland. Our analysis shows a bioethanol yield of 7414 litres a hectare each year is achievable with five-year-old agave plants."The study found that sugarcane yields 9900 litres a hectare each year. However, agave outperforms sugarcane on a range of measures, including freshwater eutrophication, marine ecotoxicity and -- crucially -- water consumption.Agave uses 69 percent less water than sugarcane and 46 percent less water than corn for the same yield. For US corn ethanol, the yield was lower than agave, at 3800 litres a hectare a year."This shows agave is an economic and environmental winner for biofuel production in the years to come," Associate Professor Tan said.
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Agriculture & Food
| 2,020 |
March 31, 2020
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https://www.sciencedaily.com/releases/2020/03/200331092717.htm
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New pathogen threatens fennel yield in Italy
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A new fennel fungal disease caused by a new genus and species --
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Fennel, a crop native in arid and semi-arid regions of southern Europe and the Mediterranean area is massively used as a vegetable, herb and seed spice in food, pharmaceutical, cosmetic and healthcare industries with Italy taking the world-leading production. It is an important and widely cultivated crop in Sicily (southern Italy).Worldwide, fennel crops are affected by several fungal diseases. In Italy, amongst soilborne diseases, there have been reports of brown rot and wilt caused by International research group, led by Ms. Dalia Aiello from the University of Catania, made the first step in handling the new fennel disease by identifying the causal agent obtained from symptomatic plants and publishing the results of their research in the open-access journal In order to understand the origin of the causal agent, scientists collected 30 samples during several surveys in the affected areas in Sicily, and studied the consistently grown fungal colonies from symptomatic tissues."The fungal species obtained from symptomatic tissues was identified based on morphological characters and molecular phylogenetic analyses of an ITS-LSU-SSU rDNA matrix, resulting in the description of the fennel pathogen as a new genus and species, According to the pathogenicity tests, O. foeniculi causes symptoms on artificially inoculated plants of the same cultivar. Preliminary evaluation of fennel germplasm, according to the susceptibility to the new disease, shows that some cultivars ("Narciso," "Apollo" and "Pompeo") are more susceptible and some are less susceptible ("Aurelio," "Archimede" and "Pegaso"), but this is a subject yet to be confirmed by additional investigations. More studies are required in order to plan further effective disease management strategies."On the basis of the disease incidence and severity observed in the field, we believe that this disease represents a serious threat to fennel crop in Sicily and may become a major problem also to other areas of fennel production if accidentally introduced," concludes Dr. Dalia Aiello.
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Agriculture & Food
| 2,020 |
March 30, 2020
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https://www.sciencedaily.com/releases/2020/03/200330093422.htm
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Novel chemistry could protect crops from fungal disease
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Pathogenic fungi pose a huge and growing threat to global food security.
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Currently, we protect our crops against fungal disease by spraying them with anti-fungal chemistries, also known as fungicides.However, the growing threat of microbial resistance against these chemistries requires continuous development of new fungicides.A consortium of researchers from the University of Exeter, led by Professor Gero Steinberg, combined their expertise to join the fight against plant pathogenic fungi.In a recent publication, in the scientific journal These diseases challenge temperate-grown wheat and rice, respectively, and so jeopardise the security of our two most important calorie crops.The scientists' journey started with the discovery that MALCs inhibit the activity of fungal mitochondria.Mitochondria are the cellular "power-house," required to provide the "fuel" for all essential processes in the pathogen.By inhibiting an essential pathway in mitochondria, MALCs cut down the cellular energy supply, which eventually kills the pathogen.Whilst Steinberg and colleagues show that this "mode of action" is common to the various MALCs tested, and effective against plant pathogenic fungi, one MALC that they synthesised and named C18-SMe2+ showed unexpected additional modes of action.Firstly, C18-SMe2+ generates aggressive molecules inside the mitochondria, which target life-essential fungal proteins, and in turn initiate a "self-destruction" programme, which ultimately results in "cellular suicide" of the fungus.Secondly, when applied to crop plants, C18-SMe2+ "alerts" the plant defence system, which prepares the crop for subsequent attack, thereby increasing the armoury of the plant against the intruder.Most importantly, the Exeter researchers demonstrate that C18-SMe2+ shows no toxicity to plants and is less toxic to aquatic organisms and human cells than existing fungicides sprayed used in the field today.Professor Steinberg said: "It is the combined approach of Exeter scientists, providing skills in fungal cell biology (myself, Dr Martin Schuster), fungal plant pathology (Professor Sarah J. Gurr), human cell biology (Professor Michael Schrader) and synthetic chemistry (Dr Mark Wood) that enabled us to develop and characterise this potent chemistry."The University has filed a patent (GB 1904744.8), in recognition of the potential of this novel chemistry in our perpetual fight against fungi."We now seek partners/investors to take this development to the field and prove its usefulness under 'real agricultural conditions'. Our long-term aim is to foster greater food security, in particular in developing nations."Professor Steinberg added: "I always wanted to apply my research outside of the ivory tower of academia and combine the fundamental aspects of my work with a useful application."The visionary approach of the Biological Sciences Research Council (BBSRC) provided me with this opportunity, for which I am very grateful. In my mind, this project is a strong example of translational research that benefits the public."Professor Sarah Gurr said: "This is such a timely and important study. We are increasingly aware of the growing burden of plant disease caused by fungi and of our need to safe-guard our calorie and commodity crops better."The challenge is not only to discover and describe the mode of action of new antifungals but to ensure that chemistries potent against fungi do not harm plants, wildlife or human health."This new antifungal is thus an exciting discovery and its usefulness may extend beyond crops into the realms of fungal disease in humans and, indeed to various applications in the paint and preservative industries. This merits investment!"
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Agriculture & Food
| 2,020 |
March 27, 2020
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https://www.sciencedaily.com/releases/2020/03/200327113658.htm
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Animals keep viruses in the sea in balance
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A variety of sea animals can take up virus particles while filtering seawater for oxygen and food. Sponges are particularly efficient. That was written by marine ecologist Jennifer Welsh from NIOZ this week, in a publication in Nature Scientific Reports. This Monday, Welsh will defend her thesis at the Free University of Amsterdam, through an online connection.
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"When a virus infects a cell," says Jennifer Welsh of the Royal Netherlands Institute for Sea Research (NIOZ), "it uses its host to make new viruses. After those are released, they can, in turn, infect many more, new cells." However, Welsh discovered that the many virus particles in the sea -- over 150 million in a glass of sea water -- can also end up for, a large part, as the lunch of a diverse group of sea animals.The Japanese oyster, for example, filters seawater to extract oxygen or food such as algae and bacteria. While doing this, it ingests virus particles. Welsh: "In our experiments, during which we did not offer the oysters any food and hence they only filtered the water for oxygen uptake, Japanese oysters removed 12 per cent of the virus particles from the water."That number puts the oyster in the fourth place of all species that Welsh looked at in the NIOZ Virus Ecology Lab on Texel. "Of all non-host organisms that we tested, sponges, crabs and cockles made it to the podium. In our experiments, the sponges reduced the presence of viruses by up to 94 per cent within three hours. Another experiment showed that the uptake of viruses happens indeed very quickly and effectively, even if we offered new viruses to the water every 20 minutes, the sponges remained tremendously effective in removing viruses."Until now, it was unknown that several species of sea animals can have such a significant influence on virus populations. "The influence of non-host organisms in the ambient environment, really is a factor that has been overlooked in virus ecology," Welsh says.However, Welsh does not assume that the results of her lab experiments will be so clear cut when applied to the natural habitat. "The situation there is much more complex, as many other animal species are present and influence one another. For example, if an oyster is filtering and a crab comes along, it closes its valve and stops filtering. In addition, there are factors such as tidal currents, temperature and UV light to consider. But also in nature, predation by non-host should definitely be taken into account."Nevertheless, the new insights might in time be useful in aquaculture. In this sector, fish or shellfish that are meant for consumption, are kept in enclosures, such as sea cages or basins, whereby there is a direct connection to the sea. Aquaculture is becoming larger as a sustainable alternative to fishing at sea, but is much criticised, mostly by nature conservationists.Welsh explains why: "In salt water farms, tremendous amounts of specimens of one single species live together in monoculture. If a contagious disease breaks out, the risks are high that the pathogen spreads to the wild populations living in the sea. With the addition of enough sponges, the danger of a virus outbreak would possibly be nipped in the bud. The results of this research show that this would be good follow up research project."On Monday 30 March, Jennifer Welsh will be the first NIOZ-researcher to defend her dissertation through the internet. "I will be defending my degree in the middle of a crisis caused by COVID-19, a corona virus that, by now, we all know and have been affected by. Due to the imposed restrictions, I will answer the questions of the committee online. Just my boyfriend, who happens to be one of my paranymfs, will be there with me. My apartment is very small, so I may end up defending my thesis on my bed with my laptop."
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Agriculture & Food
| 2,020 |
March 26, 2020
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https://www.sciencedaily.com/releases/2020/03/200326144419.htm
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Reducing reliance on nitrogen fertilizers with biological nitrogen fixation
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Crop yields have increased substantially over the past decades, occurring alongside the increasing use of nitrogen fertilizer. While nitrogen fertilizer benefits crop growth, it has negative effects on the environment and climate, as it requires a great amount of energy to produce. Many scientists are seeking ways to develop more sustainable practices that maintain high crop yields with reduced inputs.
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"A more sustainable way to provide nitrogen to crops would be through the use of biological nitrogen fixation, a practice well developed for leguminous crops," says plant pathologist Gary Stacey of the University of Missouri. "A variety of nitrogen fixing bacteria are common in the rhizosphere of most plants. However, such plant growth promoting bacteria (PGPB) have seen only limited use as inoculants in agriculture."Stacey and his college believe that this limited use is due to the general problems associated with the use of biologicals for crop production and variable efficacy upon application. They conducted research to gain a greater understanding of the metabolic response of the plant host in order to reduce the variability seen with the response of crops to PGPB."One challenge with our research is that, while PGPB can colonize roots to high levels, the sites of colonization can be highly localized," said Stacey. "Hence, isolating whole roots results in a considerable dilution of any signal due to the great majority of the root cells not in contact with the bacteria."To overcome this challenge, Stacey and his team utilized laser ablation electrospray ionization mass spectrometry (LAESI-MS), which allowed them to sample only those sites infected by the bacteria, which they could localized due to expression of green fluorescent protein.Their results showed that bacterial colonization results in significant shifts in plant metabolism, with some metabolites more significantly abundant in inoculated plants and others, including metabolites indicative of nitrogen, were reduced in roots uninoculated or inoculated with a bacterial strain unable to fix nitrogen."Interestingly, compounds, involved in indole-alkaloid biosynthesis were more abundant in the roots colonized by the fix- strain, perhaps reflecting a plant defense response," said Stacey. "Ultimately, through such research, we hope to define the molecular mechanisms by which PGPB stimulate plant growth so as to devise effective and consistent inoculation protocols to improve crop performance."Stacey's lab has long been interested in biological nitrogen fixation and plant-microbe interactions in general. Since the discovery of biological nitrogen fixation (BNF), the lab has had a goal to convey the benefits of BNF to non-leguminous crops such as maize. PGPB have this ability in nature but this has not been adequately captured for practical agricultural production."We believe that, in contrast to other better studied interactions, such as rhizobium-legume, this is due to a general lack of information about the molecular mechanisms by which PGPB stimulate plant growth. Hence, we have undertaken in our lab projects that seek to provide this information in the belief that such information will increase the efficacy of PGPG inoculants with the net effect to increase their use for crop production."Stacey and his team were most surprised to find that they did not see a significant impact on phytohormone production that correlated tightly with the ability of PGPB to enhance plant growth. This suggests that PGPB impact plant metabolism to a greater extent than previously realized, pointing perhaps to more complex explanations for how these bacteria impact plant growth.
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Agriculture & Food
| 2,020 |
March 26, 2020
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https://www.sciencedaily.com/releases/2020/03/200326124143.htm
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Local community involvement crucial to restoring tropical peatlands
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Local community involvement is vital in efforts to raise water levels to help restore Indonesia's tropical peatlands, a new study has found.
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Unspoilt peatlands act as a carbon sink and play an important role in reducing global carbon emissions. They are also a crucial habitat for many birds and animals, including endangered species such as orang-utans and tigers.Draining peatland for farming destroys habitats and causes the peat to emit the carbon it once stored. The dry land also becomes prone to fire -- leading to increased carbon emissions and a threat to the lives of many species including humans.The study, led by researchers at the University of York, interviewed people involved in work to conserve and restore Indonesia's 15 million hectares of peatland -- more than half of which has been drained and converted to cropland.The international team, which included researchers from Jambi University and the Indonesia Soil Research Institute, gained the views of scientists, charities, and government officials. All participants agreed that getting support from local communities and raising water levels were key to successful restoration.Lead author of the study, Dr Caroline Ward from the Leverhulme Centre for Anthropocene Biodiversity at the University of York, said: "While many peatlands in Indonesia have been drained for large palm oil plantations, many hectares have also been drained for local smallholders and farmers to grow crops on."Many of these local people have no other option but to use the land in this way. Efforts need to be made across all stakeholders involved in peatland restoration to provide people with an alternative source of income or a crop which can be farmed in a more sustainable way."Restoring drained peatland involves a process of "re-wetting" where canals draining water away are blocked or filled in.Professor Lindsay Stringer from the University of Leeds commented that "rewetting brings the water table closer to the surface, so this makes it less likely that the peatlands will catch fire. Rewetting is often used together with revegetation and revitalisation to improve the overall peatland condition."Professor Jane Hill, project leader at the University of York, commented that "restoration of peatlands to prevent fires has huge benefits for local communities and preventing forest fires is vital for conserving wildlife."Dr Ward added that "Tropical peatland restoration is really important to reducing global carbon emissions."Our study highlights that while everyone agrees that restoration of peatland is crucial, there is no consensus on how this should be achieved and how much progress has been made to date."We need to gather an evidence base urgently, and establish better ways of collaborating and sharing information between different groups."
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Agriculture & Food
| 2,020 |
March 25, 2020
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https://www.sciencedaily.com/releases/2020/03/200325110900.htm
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Mapping the cannabis genome to improve crops and health
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Unlocking the full potential of cannabis for agriculture and human health will require a co-ordinated scientific effort to assemble and map the cannabis genome, says a just-published international study led by University of Saskatchewan researchers.
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In a major statistical analysis of existing data and studies published in the "Considering the importance of genomics in the development of any crop, this analysis underlines the need for a co-ordinated effort to quantify the genetic and biochemical diversity of this species," the authors state.The team, which includes scientists in The Netherlands, Germany, and the U.S., found that less than 50 per cent of the cannabis genome is accurately mapped, with about 10 per cent of the genome missing and another 10 to 25 per cent unmapped."This means that we lack the foundation on which to build a molecular breeding program for cannabis comparable to what exists for other crops," said lead author Tim Sharbel, a plant scientist in the USask College of Agriculture and Bioresources."Developing a high-quality genetic blueprint would provide the building blocks for genomics-based breeding and applications to human and animal health, while strengthening university-industry partnerships."The findings will serve as a cornerstone for various types of research conducted through the USask-led Cannabinoid Research Initiative of Saskatchewan (CRIS), said Sharbel. The multi-disciplinary team also involved USask researchers from the College of Pharmacy and Nutrition, College of Medicine, and the School of Environment and Sustainability."These data are crucial for setting up a core collection of genotypes which can be used to study various cannabis traits," he said.Sharbel noted that recent societal and governmental acceptance of cannabis has spurred growing interest by companies in medical applications of cannabis use. He is seeking medicinal plant industry partners to help fund academic research that will map, compare and make full use of the closely related genomes of cannabis, hemp, and hops."This initiative would become part of an industry-driven effort to exchange resources and improve cannabis, hemp and hops for medicinal and industrial properties," he said."If we can publish case studies to show that certain compounds can treat human disorders with statistical significance, then getting such information into the medicare system -- for example, as a basis for a Drug Identification Number assigned to a drug product before it can be marketed in Canada -- would be of great benefit to companies."Prior to joining USask, Sharbel worked on medicinal plants with both academic and industry partners for 15 years in Europe, studying the effects of the German chamomile herb on digestive disorders and St. John's wort on dementia."Medicinal plants are hugely important to society, have long traditional use throughout human history, and represent important reasons to protect biodiversity. The emergence of the cannabis industry is a good driver for a larger goal of bringing traditional medicinal plants into the mainstream," he said.The authors found, in the limited data that exists, support for the potential health benefits of cannabis, including treatments for pain, spasticity in multiple sclerosis, and opioid use reduction. The analysis also cites negative short-term effects of THC, the main psychoactive compound in cannabis, such as reduced cognitive function, enhanced anxiety and fatigue, and potential long-term consequences such as permanent loss of memory, intelligence, mental focus, and judgment, as well as addiction."It is critical to recognize cannabis and cannabinoids as drugs with potential benefits and associated risks, as would be the case for the investigation of any novel drug," the authors state.The team noted there is also evidence for developing hemp-type cannabis as a highly digestible, protein-rich food source that would be unlikely to cause an allergic reaction.
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Agriculture & Food
| 2,020 |
March 24, 2020
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https://www.sciencedaily.com/releases/2020/03/200324202031.htm
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Rats give more generously in response to the smell of hunger
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How do animals that help their brethren manage to prioritize those most in need? A study publishing March 24 in the open-access journal
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Reciprocal cooperation among unrelated individuals is widespread in the animal kingdom. For example, Norway rats (Rattus norvegicus) exchange food reciprocally and take into account both the cost of helping and the potential benefit to the receiver. Rats show their need for food through solicitation, which increases the chances they will receive help. But communication through calls and gestures may not honestly reflect the actual need of the recipient, and might instead be used to trick a potential donor into helping. In the new study, Schneeberger and colleagues used Norway rats to investigate odor as a potentially "honest cue" by which prospective donors can assess others' need for food.The researchers provided rats with odor cues from hungry or well-fed rats located in a different room. They found that the rats were quicker to provide help (by pulling a food tray within reaching distance of another rat) when they received odor cues from a hungry rat than from a well-fed one.The authors then analyzed the air from around the rats, revealing seven different volatile organic chemicals that differed significantly in their abundance between hungry and satiated rats. According to the authors, the olfactory cues may result directly from recently ingested food sources, from metabolic processes involved in digestion, or from a putative pheromone that indicates hunger. This "smell of hunger" can serve as a reliable cue of need in reciprocal cooperation, supporting the hypothesis of honest signaling.The authors add: "Rats donate food preferably to social partners in urgent need."
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Agriculture & Food
| 2,020 |
March 23, 2020
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https://www.sciencedaily.com/releases/2020/03/200323132412.htm
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Peak district grasslands hold key to global plant diversity
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Scientists at the University of Sheffield have found that plants are able to co-exist because they share key nutrients, using grasslands from the Peak District.
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In a study published in To do this they used soil taken from Peak District limestone grassland which is low in phosphorus. They then injected different types of phosphorus into the soil which allowed them to track which plants took up which type of phosphorus.Their findings show that plants are able to share out the phosphorus by each preferring to take it up in a different form. This sharing is known as resource partitioning.Professor Gareth Phoenix, from the University of Sheffield's Department of Animal and Plant Sciences, who led the study, said: "The plants had different preferences for the various phosphorus compounds. Some showed greater uptake from the inorganic phosphorus form of phosphate, some preferred to use a mineral bound phosphorus compounds such as calcium phosphate, and others were better at using the organic compound DNA. Critically, this means the plants can co-exist because they are using different chemical forms of phosphorus in the soil. In other words, they are sharing the phosphorus."Our research answers the global question of how we get very high levels of plant species biodiversity, especially in ecosystems with very low amounts of soil phosphorus. By helping to understand how we get high levels of biodiversity, we can also better protect ecosystems and conserve their biodiversity."The research used different radioactive compounds to directly trace the phosphorus from the soil into the plants to accurately trace which soil phosphorus compound the phosphorus in the plant came from. Only very tiny amounts of radioactive phosphorus are needed to detect the uptake, meaning the team could look at the natural behaviour of the plants in natural soil, and with small amounts of phosphorus, as you would find in nature.The work was funded by the Natural Environment Research Council.
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Agriculture & Food
| 2,020 |
March 20, 2020
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https://www.sciencedaily.com/releases/2020/03/200320132239.htm
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Most bird feed contains troublesome weed seeds
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Many millions of homeowners use feeders to attract birds. But a two-year study featured in the journal
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When researchers examined the contents of 98 commercially available bird feed mixes, they uncovered several significant findings:The researchers also explored which harvested bird feed ingredients contributed most to weed seed contamination. They found that proso millet grain was closely linked to the presence of pigweed species weeds, while safflower and sunflower contributed most to the presence of kochia and common ragweed, respectively."While it is difficult to estimate the precise role commercial bird feed plays, there is a distinct possibility it may be an overlooked pathway for spreading troublesome weed species into new regions," says Eric Oseland of the University of Missouri.To mitigate the risks, researchers recommend careful weed management in crop fields designated for bird feed, as well as the use of sieving during packaging to reduce weed seed contamination. They also point to the proven effectiveness of regulatory measures adopted in Europe to limit weed seed content in bird feed.
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Agriculture & Food
| 2,020 |
March 18, 2020
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https://www.sciencedaily.com/releases/2020/03/200318143704.htm
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Crop diversity can buffer the effects of climate change
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How we farm can guard against climate change and protect critical wildlife -- but only if we leave single-crop farms in the dust, according to a new Stanford study.
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The research provides a rare, long-term look at how farming practices affect bird biodiversity in Costa Rica. "Farms that are good for birds are also good for other species," said Jeffrey Smith, a graduate student in the department of biology and a co-author on the paper. "We can use birds as natural guides to help us design better agricultural systems."By and large, the team found that diversified farms are more stable in the number of birds they support, provide a more secure habitat for those birds and shield against the impacts of climate change much more effectively than single-crop farms."The tropics are expected to suffer even more intensely in terms of prolonged dry seasons, extreme heat and forest dieback under climate change," said Gretchen Daily, director of the Stanford Natural Capital Project and the Center for Conservation Biology and a senior author on the paper. "But diversified farms offer refuge -- they can buffer these harmful effects in ways similar to a natural forest ecosystem."The findings, published in this week's issue of the journal "This study shows that climate change has already been impacting wildlife communities, continues to do so, and that local farming practices really matter in protecting biodiversity and building climate resilience," said Nick Hendershot, a graduate student in the department of biology and lead author on the study.Tropical regions are some of the most species-rich in the world, but they also face the greatest threats to biodiversity. As their forests are felled to plant cash crops like bananas and sugarcane, the amount and availability of natural habitats have shrunk dramatically. Meanwhile, climate change has resulted in longer, hotter dry seasons that make species survival even more challenging."It's the one-two punch of land-use intensification and climate change," Hendershot said. "Wildlife populations are already severely stressed, with overall decreased health and population sizes in some farming landscapes. Then, these further extreme conditions like prolonged drought can come along and really just decimate a species."Until now, little had been known about how agricultural practices impact biodiversity in the long term. This study's researchers used nearly 20 years of meticulously collected field data to understand which birds live in natural tropical forests and in different types of farmland."It is only because we had these unusually extensive long-term data that we were able to detect the role of diversified farmlands in helping threatened species persist over multiple decades," said Tadashi Fukami, an associate professor of biology in the School of Humanities and Sciences and a senior author on the paper, along with Daily.The varied agricultural systems at work in Costa Rica provided the research team with an ideal laboratory for studying bird communities in intensively farmed monoculture systems, diversified multi-crop farms, and natural forests. They compared monoculture farms -- like pineapple, rice, or sugar cane -- to diversified farms that interweave multiple crops and are often bordered by ribbons of natural forest.Surprisingly, the researchers found that diversified farmlands not only provide refuge to more common bird species, they also protect some of the most threatened. Species of international conservation concern, like the Great Green Macaw and the Yellow-naped Parrot, are at risk in Costa Rica due to habitat loss and the illegal pet trade.In intensive monocrop farmlands, these species are declining. But in the diversified systems the researchers studied, the endangered birds can be found year after year."Which species are in a given place makes a huge difference -- it's not just about numbers alone, we care about who's there," Daily said. "Each bird serves a unique role as part of the machinery of nature. And the habitats they live in support us all."In Costa Rica and around the world, the researchers see opportunities to develop integrated, diversified agricultural systems that promote not only crop productivity and livelihood security, but also biodiversity. A paradigm shift towards global agricultural systems could help human and wildlife communities adapt to a changing climate, Daily said."There are so many cash crops that thrive in diversified farms. Bananas and coffee are two great examples from Costa Rica -- they're planted together, and the taller banana plant shades the temperature-sensitive coffee bean," she added. "The two crops together provide more habitat opportunity than just one alone, and they also provide a diversified income stream for the farmer."
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Agriculture & Food
| 2,020 |
March 18, 2020
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https://www.sciencedaily.com/releases/2020/03/200318104449.htm
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To reap heart benefits of a plant-based diet, avoid junk food
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Plant-based diets are becoming more popular in many areas of the world, but the health benefits of this dietary pattern may depend largely on the specific foods consumed. A new study being presented at the American College of Cardiology's Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC) suggests that people following a plant-based diet who frequently consumed less-healthful foods like sweets, refined grains and juice showed no heart health benefit compared with those who did not eat a plant-based diet.
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"Based on these results, it seems that simply following a plant-based or vegetarian diet is not enough to reduce cardiovascular disease risk," said Demosthenes Panagiotakos, PhD, professor of biostatistics, research methods and epidemiology at Harokopio University of Athens, Greece and the study's lead author. "It is also important to focus on specific, healthful plant-based food groups to see a benefit in terms of reducing cardiovascular disease."Researchers tracked eating behavior and the development of heart disease among more than 2,000 Greek adults over a 10-year period, beginning in 2002. Participants were asked to complete a detailed food frequency survey at the time of enrollment, after five years and after 10 years.At the end of the study period, researchers analyzed the relationship between diet and the development of cardiovascular disease using a dietary index that divided participants into three groups based on the number of animal-based foods (which included meats as well as animal-derived products such as eggs and dairy) they consumed per day. Overall, men eating fewer animal-based foods were 25% less likely to develop heart disease compared to men eating more animal-based foods. The same overall trend was seen in women, but the relationship was less strong, with an overall risk reduction of about 11% among women eating the fewest animal-based foods.Even though the difference in cardiovascular disease risk was significant between these groups, the overall difference in consumption of animal-based foods was relatively small. Those following a more plant-based diet consumed, on average, three animal-based foods daily while those following a less plant-based diet consumed five."These findings highlight that even a small reduction in the daily consumption of animal-based products -- principally the less healthy foods, such as processed meat products -- accompanied by an increase in healthy plant-based foods may contribute to better cardiovascular health," Panagiotakos said.Focusing in on participants who followed a more plant-based diet, researchers then categorized each participant's diet as either healthful (reflecting increased consumption of fruits, vegetables, whole grains, nuts, legumes, oils and tea or coffee) or unhealthful (reflecting increased consumption of juices,sweetened beverages, refined grains, potatoes and sweets). Only participants following a healthful plant-based diet had a significant reduction in cardiovascular risk compared to those who ate more animal-based products.Differences in eating patterns -- and associated cardiovascular risk reduction -- were also observed between women and men. In general, men ate about three times per day while women tended to snack more, eating four to five times daily. At the same time, women showed a more dramatic increase in heart disease risk when eating an unhealthful plant-based diet and a more dramatic reduction in risk when eating a healthful plant-based diet compared to men who fell into the same two categories. This suggests that snacking on healthful foods can be beneficial while snacking on unhealthful foods can bring higher risks, Panagiotakos said.The study was limited by its reliance on questionnaires to track participants' diets. However, the findings bolster evidence for the heart health benefits of a plant-based diet and could help inform future dietary guidance for prevention of cardiovascular disease."In the future, I believe it will be useful if cardiovascular disease prevention guidelines offer clearer and specific nutrition suggestions, in terms of the types of foods that are recommended and the portions that should be consumed," Panagiotakos said.This study received funding from the Hellenic Cardiology Society, Hellenic Atherosclerosis Society and the pharmaceutical industry.
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Agriculture & Food
| 2,020 |
March 18, 2020
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https://www.sciencedaily.com/releases/2020/03/200318104427.htm
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Comparisons of organic and conventional agriculture need to be better, say researchers
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The environmental effects of agriculture and food are hotly debated. But the most widely used method of analysis often tends to overlook vital factors, such as biodiversity, soil quality, pesticide impacts and societal shifts, and these oversights can lead to wrong conclusions on the merits of intensive and organic agriculture. This is according to a trio of researchers writing in the journal
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The most common method for assessing the environmental impacts of agriculture and food is Life Cycle Assessment (LCA). Studies using this method sometimes claim that organic agriculture is actually worse for the climate, because it has lower yields, and therefore uses more land to make up for this. For example, a recent study in But according to three researchers from France, Denmark and Sweden, presenting an analysis of many LCA studies in the journal "We are worried that LCA gives too narrow a picture, and we risk making bad decisions politically and socially. When comparing organic and intensive farming, there are wider effects that the current approach does not adequately consider," says Hayo van der Werf of the French National Institute of Agricultural Research.Biodiversity, for example, is of vital importance to the health and resilience of ecosystems. But globally, it is declining, Intensive agriculture has been shown to be one of the main drivers of negative trends such as insect and bird decline. Agriculture occupies more than one-third of global land area, so any links between biodiversity losses and agriculture are hugely important."But our analysis shows that current LCA studies rarely factor in biodiversity, and consequently, they usually miss that wider benefit of organic agriculture," says Marie Trydeman Knudsen from Aarhus University, Denmark. "Earlier studies have already shown that organic fields support biodiversity levels approximately 30% higher than conventional fields."Usage of pesticides is another factor to consider. Between 1990 and 2015, pesticide use worldwide has increased 73%. Pesticide residues in the ground and in water and food can be harmful to human health, terrestrial and aquatic ecosystems, and cause biodiversity losses. Organic farming, meanwhile, precludes the use of synthetic pesticides. But few LCA studies account for these effects.Land degradation and lower soil quality resulting from unsustainable land management is also an issue -- again, something rarely measured in LCA studies. The benefits of organic farming practices such as varied crop rotation and the use of organic fertilisers are often overlooked in LCA studies.Crucially, LCA generally assesses environmental impacts per kilogram of product. This favours intensive systems that may have lower impacts per kilogram, while having higher impacts per hectare of land."LCA simply looks at the overall yields. Of course, from that perspective, it's true that intensive farming methods are indeed more effective. But this is not the whole story of the larger agroecosystem. A diverse landscape with smaller fields, hedgerows and a variety of crops gives other benefits -- greater biodiversity, for example," says Christel Cederberg of Chalmers University of Technology, Sweden.LCA's product-focused approach also fails to capture the subtleties of smaller, diverse systems which are more reliant on ecological processes, and adapted to local soil, climate and ecosystem characteristics. LCA needs a more fine-grained approach."We often look at the effects at the global food chain level, but we need to be much better at considering the environmental effects at the local level," says Marie Trydeman Knudsen. The researchers note in their study that efforts are being made in this area, but much more progress is needed.A further key weakness is when hypothetical "indirect effects" are included, such as assuming that the lower yields of organic agriculture lead to increased carbon dioxide emissions, because more land is needed. For example, another prominent study -- from a researcher also based at Chalmers University of Technology -- suggested that organic agriculture was worse for the climate, because the requirement for more land leads indirectly to less forest area. But accounting for these indirect effects is problematic."For example, consider the growing demand for organic meat. Traditional LCA studies might simply assume that overall consumption of meat will remain the same, and therefore more land will be required. But consumers who are motivated to buy organic meat for environmental and ethical reasons will probably also buy fewer animal-based products in the first place. But hardly any studies into this sort of consumer behaviour exist, so it is very difficult to account for these types of social shifts now," says Hayo van der Werf."Current LCA methodology and practice is simply not good enough to assess agroecological systems such as organic agriculture. It therefore needs to be improved and integrated with other environmental assessment tools to get a more balanced picture" says Christel Cederberg.
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Agriculture & Food
| 2,020 |
March 17, 2020
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https://www.sciencedaily.com/releases/2020/03/200317215632.htm
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Pesticide seed coatings are widespread but underreported
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Pesticide-coated seeds -- such as neonicotinoids, many of which are highly toxic to both pest and beneficial insects -- are increasingly used in the major field crops, but are underreported, in part, because farmers often do not know what pesticides are on their seeds, according to an international team of researchers. The lack of data may complicate efforts to evaluate the value of different pest management strategies, while also protecting human health and the environment.
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"We reviewed existing evidence, as well as proprietary and novel government data, on seed treatment usage and found that many farmers either did not know what pesticides were on their seeds or falsely assumed that seed treatments did not include certain pesticides," said Paul Esker, assistant professor of epidemiology and crop pathology, Penn State. "This lack of knowledge could lead to overuse of pesticides, which could harm the environment and farmers' health."The team analyzed proprietary data from Kynetec, a third-party global marketing and research firm that maintains one of the most comprehensive datasets on pesticide use in the United States, collected from 2004-2014. They found that the use of seed treatments in the U.S. grew over the past decade, particularly in corn and soybean production. In the 2012 to 2014 period, 90 percent of corn acres and 76 percent of soybean acres were grown with treated seeds. Of the insecticides applied to seeds, neonicotinoids accounted for roughly 80%.Next, the researchers analyzed farmers' responses to questions about pesticide-coated seeds documented in the Agricultural Resource Management Survey (ARMS) -- the U.S. Department of Agriculture's primary source of information on the production practices, resource use and economic well-being of America's farms and ranches. Specifically, they examined farmer responses to the ARMS for cotton in 2015, corn in 2016, wheat in 2017 and soybean in 2018.They found that around 98% of farmers were able to provide the names of the field-applied pesticides used on their cotton, corn, wheat or soybean crops. By contrast, only 84% of cotton growers, 65% of corn growers, 62% of soybean growers, 57% of winter wheat growers and 43% of spring wheat growers could provide the name of the seed-treatment product on their crops. The rest either did not answer the survey question or specified that they did not know.The researchers also found that, in 2015, cotton growers reported that 13% of total acreage was not treated with an insecticide and 19% was not treated with a fungicide, while simultaneously reporting the use of products containing those types of pesticides on that acreage.The results appear today (March 17) in the journal "One of the most important findings of this study is that farmers know less about pesticides applied to their seeds than pesticides applied in other ways," said Margaret Douglas, assistant professor of environmental studies, Dickinson College. "This is likely because seed is often sold with a 'default' treatment that contains a mix of different pesticide active ingredients, and the treated seed is exempt from some labeling requirements. Without knowing what is on their seeds, it is nearly impossible for farmers to tailor pesticide use to production and environmental goals."According to the study's lead author Claudia Hitaj, research and technology associate, Luxembourg Institute of Science and Technology, the lack of information on the use of pesticidal seed treatments means that a significant portion of pesticide use, particularly for active ingredients that are applied almost exclusively as seed treatments, is not captured in existing pesticide-use datasets."Reliable data on pesticide use is needed by regulators, farmers, and researchers to increase agricultural production and profitability and to protect human health and the environment from the adverse effects of pesticides," she said.By comparing the data Kynetec collected during the 2004-2014 window to that collected in 2015, when Kynetec stopped offering information on seed treatments, the team found a significant drop in pesticide use for a number of pesticides known to be used as seed treatments. The researchers used clothianidin as an example of what can happen as a result of poor tracking of pesticide-treated seed use."The removal of data on treated seed makes clothianidin use appear to drop from more than 1.5 million kg/year in 2014 to less than a tenth of a million kg/year in 2015," said Aimee Code, pesticide program director, Xerces Society for Invertebrate Conservation. "Clothianidin is currently undergoing review by the U.S. Environmental Protection Agency, so the lost data makes it difficult to ensure accurate risk assessment."The team concluded that farmers, researchers and regulators could benefit from improved labelling of pesticide-treated seeds and posting of information about the active ingredients contained in treated seed products on public websites. In addition, information could be collected through sales data from seed retailers and other companies. And information about the planting location of treated seeds could help in assessing pest resistance and the local effects of pesticides on the environment."The lack of knowledge by farmers about the pesticides applied to seed is an example of why it is important to maintain a strong university extension system that can provide up-to-date information about different seed treatments, what these treatments do, and what the empirical data shows," said Esker. "This is also an opportunity for further collaboration among different disciplines, like agronomy, plant pathology, entomology, economics and environmental science, to address farm issues from a whole-system perspective."Other authors on the paper include David Smith, former economist, Economic Research Service of the U.S. Department of Agriculture, and Seth Wechsler, agricultural economist, Animal and Plant Health Inspection Service, U.S. Department of Agriculture.The National Science Foundation and the U.S. Department of Agriculture supported this research.
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Agriculture & Food
| 2,020 |
March 17, 2020
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https://www.sciencedaily.com/releases/2020/03/200317155841.htm
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Common treatments used on cattle have devastating impacts on wildlife, new study reveals
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Experts have stressed an urgent need to find alternatives to wormers and anti-ectoparasitic products used widely on cattle, following the findings of a study just published in
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Researchers from the University of Sussex looked at a body of published evidence into the environmental impact of anthelmintics -- products used as wormers and anti-parasitic agents and widely applied across the world. They found that, across all drug classes, the products were having a devastating impact on dung beetles -- species that are vital prey items for a range of bat and bird species.The study conducted by Domhnall Finch and Professor Fiona Mathews also found that some of the products actively attracted adult dung beetles, before impairing the development of their larvae.Fiona Mathews, Professor of Environmental Biology at the University of Sussex, said: "When compared with controls, we found that dung samples from cattle treated with these products had about a third fewer dung beetle larvae."What's particularly worrying is that the beetles actually seemed to be more attracted to treated dung but, because of the toxicity of the chemicals, their larvae have poor survival rates and face impaired development."Over time, this reduces the number of dung beetles which is troubling news for a range of bird and bat species -- for which dung beetles are key prey items."Many of these species are already listed as vulnerable so any decline in prey availability is a serious concern."Dung beetles are commonly preyed upon by the serotine bat, noted as Vulnerable to Extinction on the new British Red List; the greater horseshoe bat, protected under European Law because of its perilous conservation status right across Europe; and the Nightjar and the Chough, both of which are protected by the Wildlife and Countryside Act 1981. The Nightjar has been given an amber UK conservation status.The study, published in the journal But the authors stress that more research is needed into the other treatment types and newer drugs in order to determine the exact effects of each.The results are particularly timely as they come just a few months after the government announced that it would not be funding extensions to higher-tier organic stewardship agreements in England. This means that farms who currently avoid the use of insecticides will be faced with a difficult choice moving forward.Prof. Mathews explained: "Many farmers are now facing a gap in their income as they have to make new applications. Sticking to an insecticide-free approach may not be economically attractive compared with switching to conventional systems where the routine use of anti-parasitic agents is normal. Once applied, the residues can remain in the soil -- affecting a wide range of invertebrates -- for months.""Some of these farms are also critical for British wildlife, particularly rare bats, and the introduction of chemicals could really impact their numbers -- as demonstrated in our study."Dung beetles themselves provide important ecosystem services for farmers. By ensuring that dung is cleared from pasture quickly, they help to control pest flies and also allow for rapid grass regrowth through nutrient cycling, soil aeration and dung removal. The presence of dung beetles has also been shown to reduce the prevalence of cattle nematode infections by 55 to 89% (Fincher 1975) and pest flies by 58% (Benyon et al. 2015). In the UK alone, these services are estimated to exceed £350M per year.Domhnall Finch, doctoral student at the University of Sussex, said: "Dung beetles are an overlooked but hugely important part of our landscape."Studies have proven that they can help to reduce the prevalence of worm infections in cattle, which is ironic when we consider that they're now under threat from chemical products which essentially do the same thing."While more research is needed to determine the effects of newer agents, our work has clearly shown that those chemicals which are present in pour-on treatments have a long-lasting negative impact."There is an urgent need to find alternatives."
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Agriculture & Food
| 2,020 |
March 17, 2020
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https://www.sciencedaily.com/releases/2020/03/200317130716.htm
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Plant water saving system works like clockwork, it transpires
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Plants, just like humans, have circadian clocks that allow them to tell the time. In humans this cellular clockwork influences when we wake and sleep.
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Plants are so dependent on daylight that circadian clocks are even more influential, regulating the rate of photosynthesis, gas exchange, and transpiration, which is the flow of water through the stem and evaporation from leaves.Now researchers have discovered that these biological clocks play a critical role in the consumption of water, allowing plants to use this precious resource more efficiently.They carried out a series of experiments with model laboratory plants in which the genes encoding circadian rhythms had been changed.Some changes made plants use more water in relation to growth but, unexpectedly, the experiments revealed that some of these changes to circadian rhythms allowed plants to grow strong and healthily whilst using less water. The study reveals that it is the whole circadian system that affects water use efficiency not just a specific part.The research opens an opportunity for the tuning of crops to use water more efficiently: losing less water through transpiration whilst still growing.Agriculture accounts for around 80% of freshwater used worldwide. So, understanding processes in plants that affect the amount of water they use is vitally important to develop crops that are productive but use less water.Plants transpire water with a daily rhythm because the stomata, tiny pores on the surface of leaves, generally open only in the day. Previous studies showed that daily opening is regulated by circadian rhythms."We reasoned that circadian rhythms might have a big impact upon the amount of water that plants use. And our experiments show this to be the case," explains Dr Antony Dodd of the John Innes Centre, who is the senior author of the study."The overarching goal of the work lies in reducing the amount of water that is used in crop irrigation to improve the sustainability of agricultural food production."The study reveals that the altered circadian clock genes affect water use efficiency through a variety of ways. Along with adjusting the process of transpiration, the altered clock influences how big leaves grow which effects how much water the plant uses. These changes together with others account for the improvements in water use efficiency the researchers observed.The next steps of the study will be to discover the cellular mechanisms that explain how circadian rhythms regulate plant water loss and establish the importance of the findings in key crops, using the knowledge from the model plants used in this study. Further work could involve investigating the role of temperature in how the clock affects water use efficiency.The research was funded by BBSRC (the GEN ISP at JIC and the SWBio PhD programme in Bristol), and was in collaboration with Prof Alistair Hetherington (University of Bristol).The circadian clock contributes to the long-term water efficiency of Arabidopsis appears in
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Agriculture & Food
| 2,020 |
March 17, 2020
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https://www.sciencedaily.com/releases/2020/03/200317130713.htm
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Urban land could grow fruit and vegetables for 15 per cent of the population
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Growing fruit and vegetables in just 10 per cent of a city's gardens and other urban green spaces could provide 15 per cent of the local population with their 'five a day', according to new research.
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In a study published in They found that green spaces including parks, gardens, allotments, roadside verges and woodland cover 45 per cent of Sheffield -- a figure similar to other UK cities.Allotments cover 1.3 per cent of this, while 38 per cent of green space comprised of domestic gardens, which have immediate potential to start growing food.The interdisciplinary team used data from Ordnance Survey and Google Earth to reveal that an extra 15 per cent of the city's green space, such as parks and roadside verges, also has potential to be converted into community gardens or allotments.Putting domestic gardens, allotments and suitable public green spaces together would open up 98m2 per person in Sheffield for growing food. This equates to more than four times the 23m2 per person currently used for commercial horticulture across the UK.If 100 per cent of this space was used for growing food, it could feed approximately 709,000 people per year their 'five a day', or 122 per cent of the population of Sheffield. But even converting a more realistic 10 per cent of domestic gardens and 10 per cent of available green space, as well as maintaining current allotment land, could provide 15 per cent of the local population -- 87,375 people -- with sufficient fruit and veg.With just 16 per cent of fruit and 53 per cent of vegetables sold in the UK grown domestically, such a move could significantly improve the nation's food security.The study also investigated the potential for soil-free farming on flat roofs using methods such as hydroponics, where plants are grown in a nutrient solution, and aquaponics, a system combining fish and plants. These techniques could allow year-round cultivation with minimal lighting requirements, using greenhouses powered by renewable energy and heat captured from buildings, with rainwater harvesting for irrigation.Flat roofs were found to cover 32 hectares of land in Sheffield city centre. While equivalent to just 0.5m2 per person, the researchers believe the high-yielding nature of soil-free farming means this could make a significant contribution to local horticulture.The UK currently imports 86 per cent of its total tomato supply -- but if just 10 per cent of the flat roofs identified within the centre of Sheffield became soil-free tomato farms, it would be possible to grow enough to feed more than eight per cent of the population one of their 'five a day'. This increases to more than 60 per cent of people if three quarters of the flat roof area is utilised.Dr Jill Edmondson, Environmental Scientist at the University of Sheffield and lead author of the study, said: "At the moment, the UK is utterly dependent on complex international supply chains for the vast majority of our fruit and half of our veg -- but our research suggests there is more than enough space to grow what we need on our doorsteps."Even farming a small percentage of available land could transform the health of urban populations, enhance a city's environment and help build a more resilient food system."Professor Duncan Cameron, co-author and Director of the Institute for Sustainable Food at the University of Sheffield, said: "It will take significant cultural and social change to achieve the enormous growing potential of our cities -- and it's crucial that authorities work closely with communities to find the right balance between green space and horticulture."But with careful management of green spaces and the use of technology to create distribution networks, we could see the rise of 'smart food cities', where local growers can support their communities with fresh, sustainable food."The Institute for Sustainable Food at the University of Sheffield brings together multidisciplinary expertise and world-class research facilities to help achieve food security and protect the natural resources we all depend on.
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Agriculture & Food
| 2,020 |
March 16, 2020
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https://www.sciencedaily.com/releases/2020/03/200316152211.htm
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Even a limited India-Pakistan nuclear war would bring global famine, says study
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The concept of nuclear winter -- a years-long planetary freeze brought on by airborne soot generated by nuclear bombs -- has been around for decades. But such speculations have been based largely on back-of-the-envelope calculations involving a total war between Russia and the United States. Now, a new multinational study incorporating the latest models of global climate, crop production and trade examines the possible effects of a less gargantuan but perhaps more likely exchange between two longtime nuclear-armed enemies: India and Pakistan. It suggests that even a limited war between the two would cause unprecedented planet-wide food shortages and probable starvation lasting more than a decade. The study appears this week in the journal
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Of an estimated 14,000 nuclear warheads worldwide, close to 95 percent belong to the United States and Russia. India and Pakistan are thought to have about 150 each. The study examines the potential effects if they were to each set off 50 Hiroshima-size bombs -- less than 1 percent of the estimated world arsenal.In addition to direct death and destruction, the authors say that firestorms following the bombings would launch some 5 million tons of soot toward the stratosphere. There, it would spread globally and remain, absorbing sunlight and lowering global mean temperatures by about 1.8 degrees C (3.25 F) for at least five years. The scientists project that this would in turn cause production of the world's four main cereal crops -- maize, wheat, soybeans and rice -- to plummet an average 11 percent over that period, with tapering effects lasting another five to 10 years."Even this regional, limited war would have devastating indirect implications worldwide," said Jonas Jägermeyr, a postdoctoral scientist at the NASA Goddard Institute for Space Studies who led the study. "It would exceed the largest famine in documented history."According to the study, crops would be hardest hit in the northerly breadbasket regions of the United States, Canada, Europe, Russia and China. But paradoxically, southerly regions would suffer much more hunger. That is because many developed nations in the north produce huge surpluses, which are largely exported to nations in the Global South that are barely able to feed themselves. If these surpluses were to dry up, the effects would ripple out through the global trade system. The authors estimate that some 70 largely poor countries with a cumulative population of 1.3 billion people would then see food supplies drop more than 20 percent.Some adverse effects on crops would come from shifts in precipitation and solar radiation, but the great majority would stem from drops in temperature, according to the study. Crops would suffer most in countries north of 30 degrees simply because temperatures there are lower and growing seasons shorter to begin with. Even modest declines in growing-season warmth could leave crops struggling to mature, and susceptible to deadly cold snaps. As a result, harvests of maize, the world's main cereal crop, could drop by nearly 20 percent in the United States, and an astonishing 50 percent in Russia. Wheat and soybeans, the second and third most important cereals, would also see steep declines. In southerly latitudes, rice might not suffer as badly, and cooler temperatures might even increase maize harvests in parts of South America and Africa. But this would do little to offset the much larger declines in other regions, according to the study.Since many developed countries produce surpluses for export, their excess production and reserves might tide them over for at least a few years before shortages set in. But this would come at the expense of countries in the Global South. Developed nations almost certainly would impose export bans in order to protect their own populations, and by year four or five, many nations that today already struggle with malnutrition would see catastrophic drops in food availability. Among those the authors list as the hardest hit: Somalia, Niger, Rwanda, Honduras, Syria, Yemen and Bangladesh.If nuclear weapons continue to exist, "they can be used with tragic consequences for the world," said study coauthor Alan Robock, a climatologist at Rutgers University who has long studied the potential effects of nuclear war. "As horrible as the direct effects of nuclear weapons would be, more people could die outside the target areas due to famine."Previously, Jägermeyr has studied the potential effects of global warming on agriculture, which most scientists agree will suffer badly. But, he said, a sudden nuclear-caused cooling would hit food systems far worse. And, looking backward, the the effects on food availability would be four times worse than any previously recorded global agriculture upsets caused by droughts, floods, or volcanic eruptions, he said.The study might be erring on the conservative side. For one, India and Pakistan may well have bombs far bigger than the ones the scientists use in their assumptions. For another, the study leaves India and Pakistan themselves out of the crop analyses, in order to avoid mixing up the direct effects of a war with the indirect ones. That aside, Jägermeyr said that one could reasonably assume that food production in the remnants of the two countries would drop essentially to zero. The scientists also did not factor in the possible effects of radioactive fallout, nor the probability that floating soot would cause the stratosphere to heat up at the same time the surface was cooling. This would in turn cause stratospheric ozone to dissipate, and similar to the effects of now-banned refrigerants, this would admit more ultraviolet rays to the Earth's surface, damaging humans and agriculture even more.Much attention has been focused recently on North Korea's nuclear program, and the potential for Iran or other countries to start up their own arsenals. But many experts have long regarded Pakistan and India as the most dangerous players, because of their history of near-continuous conflict over territory and other issues. India tested its first nuclear weapon in 1974, and when Pakistan followed in 1998, the stakes grew. The two countries have already had four full-scale conventional wars, in 1947, 1965, 1971 and 1999, along with many substantial skirmishes in between. Recently, tensions over the disputed region of Kashmir have flared again."We're not saying a nuclear conflict is around the corner. But it is important to understand what could happen," said Jägermeyr.The paper was coauthored by a total of 19 scientists from five countries, including three others from Goddard, which is affiliated with Columbia University's Earth Institute: Michael Puma, Alison Heslin and Cynthia Rosenzweig. Jägermeyr also has affiliations with the University of Chicago and Potsdam Institute for Climate Impact Research.
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Agriculture & Food
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March 16, 2020
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https://www.sciencedaily.com/releases/2020/03/200316141453.htm
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Ancient hornwort genomes could lead to crop improvement
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Some 500 million years ago -- when our continents were connected in a single land mass and most life existed underwater -- hornworts (Anthoceros) were one of the first groups of plants to colonize land. An international team led by University of Zurich (UZH) and the Boyce Thompson Institute has now sequenced three hornwort genomes, providing insights into the genetics underlying the unique biology of the group, an extant representative of the earliest land plants.
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The research team began the project in 2011. "It took us three years to figure out how hornworts can be grown and pushed through its sexual life cycle under laboratory conditions, and another three years to properly assemble and annotate its genome," says Péter Szövényi, researcher at UZH and last author of the paper.One of the researchers' goals was to find genes that play a role in hornworts' method of concentrating carbon dioxide inside chloroplasts, which boosts the plants' ability to make sugar resulting in increased yield. Hornworts are unique among land plants in this capability, but some species of algae share the trait. The researchers thus compared the hornwort genomes with those of algae and found one gene, LCIB, that is shared by the two groups of plants but not with other land plants. "If this carbon-concentrating mechanism could be installed in crop plants, then they could grow larger with the same amount of fertilizer," explains first author Fay-Wei Li, plant biologist at the Boyce Thompson Institute and Cornell University.Furthermore, hornworts live in symbiosis with fungi and cyanobacteria providing phosphorus and nitrogen to the plant. The researchers also identified 40 genes that may promote the hornworts' source of nitrogen, which comes from an interdependent relationship with cyanobacteria -- a unique feature in land plants. "If this capability of hornworts can be transferred to crop plants, many tons of nitrogen fertilizer could be saved," says Szövényi. Such a reduction in fertilizer could benefit the environment, since excess agricultural nitrogen frequently enters waterways, where it can cause deadly algal blooms. Szövényi and Li are already working on a project to understand the genetic mechanism underlying the symbiotic plant-cyanobacteria interaction.The research also shed light on the evolution of early land plants. Without stomata, most plants cannot take up carbon dioxide and thrive in the terrestrial environment. Therefore, stomata represent a key innovation in colonization of the terrestrial environment. Nevertheless, until now it was unknown whether stomata have evolved once or potentially multiple times independently in land plants. Hornworts possess stomata during their spore-producing phase. "We found that the basic genetic toolkit governing stomatal development in flowering plants is shared with hornworts," explains Szövényi. This finding is consistent with the hypothesis that stomata have evolved only once in the most recent common ancestor of land plants.Hornworts, liverworts and mosses were among the first plants to colonize land, but how the three groups were related had previously not been clear. "Our research shows clearly that hornworts, liverworts and mosses are all more closely related to each other than they are to vascular plants. We also show that liverworts and mosses are more closely related to each other than to hornworts," says Fay-Wei Li.
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Agriculture & Food
| 2,020 |
March 16, 2020
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https://www.sciencedaily.com/releases/2020/03/200316090330.htm
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Technology to screen for higher-yielding crop traits is now more accessible to scientists
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Like many industries, big data is driving innovations in agriculture. Scientists seek to analyze thousands of plants to pinpoint genetic tweaks that can boost crop production -- historically, a Herculean task. To drive progress toward higher-yielding crops, a team from the University of Illinois is revolutionizing the ability to screen plants for key traits across an entire field. In two recent studies -- published in the
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"For plant scientists, this is a major step forward," said co-first author Katherine Meacham-Hensold, a postdoctoral researcher at Illinois who led the physiological work on both studies. "Now we can quickly screen thousands of plants to identify the most promising plants to investigate further using another method that provides more in-depth information but requires more time. Sometimes knowing where to look is the biggest challenge, and this research helps address that."This work is supported by Realizing Increased Photosynthetic Efficiency (RIPE), an international research project that is creating more productive food crops by improving photosynthesis, the natural process all plants use to convert sunlight into energy and yields. RIPE is sponsored by the Bill & Melinda Gates Foundation, the U.S. Foundation for Food and Agriculture Research (FFAR), and the U.K. Government's Department for International Development (DFID).The team analyzed data collected with specialized hyperspectral cameras that capture part of the light spectrum (much of which is invisible to the human eye) that is reflected off the surface of plants. Using hyperspectral analysis, scientists can tease out meaningful information from these bands of reflected light to estimate traits related to photosynthesis."Hyperspectral cameras are expensive and their data is not accessible to scientists who lack a deep understanding of computational analysis," said Carl Bernacchi, a research plant physiologist with the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) at the Carl R. Woese Institute for Genomic Biology. "Through these studies, our team has taken a technology that was out of reach and made it more available to our research community so that we can unearth traits needed to provide farmers all over the world with higher-yielding crops."The RIPE project analyzes hundreds of plants each field season. The traditional method used to measure photosynthesis requires as much as 30 minutes per leaf. While newer technologies have increased efficiency to as little as 15 seconds per plant, the study published in JExBot has increased efficiency by an order of magnitude, allowing researchers to capture the photosynthetic capacity of hundreds to thousands of plants in a research plot.In the JExBot study, the team reviewed data from two hyperspectral cameras; one that captures spectra from 400-900 nanometers and another that captures 900-1800 nanometers. "Our previous work suggested that we should use both cameras to estimate photosynthetic capacity; however, this study suggests that only one camera that captures 400-900 is required," said co-first author Peng Fu, a RIPE postdoctoral researcher who led the computational work on both studies.In the PC&E study, the team resolved to make hyperspectral information even more meaningful and accessible to plant scientists. Using just 240 bands of reflectance spectra and a radiative transfer model, the team teased out how to identify seven important leaf traits from the hyperspectral data that are related to photosynthesis and of interest to many plant scientists."Our results suggest we do not always need 'high-resolution' reflectance data to estimate photosynthetic capacity," Fu said. "We only need around 10 hyperspectral bands -- as opposed to several hundred or even a thousand hyperspectral bands -- if the data are carefully selected. This conclusion can help pave the way to make meaningful measurements with less expensive cameras."These studies will help us map photosynthesis across different scales from the leaf level to the field level to identify plants with promising traits for further study.The RIPE project and its sponsors are committed to ensuring Global Access and making the project's technologies available to the farmers who need them the most.
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Agriculture & Food
| 2,020 |
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