Date
stringlengths 11
18
| Link
stringlengths 62
62
| Title
stringlengths 16
148
| Summary
stringlengths 1
2.68k
| Body
stringlengths 22
13k
⌀ | Category
stringclasses 20
values | Year
int64 2k
2.02k
|
|---|---|---|---|---|---|---|
August 19, 2019
|
https://www.sciencedaily.com/releases/2019/08/190819112737.htm
|
National livestock movement bans may prove economically damaging
|
New research from the University of Warwick has pioneered an economic perspective on controlling livestock diseases. Focusing on Foot and Mouth Disease (FMD), bovine TB (bTB) and bluetongue virus (BTV), the researchers draw striking conclusions about the role of movement bans in controlling an outbreak.
|
In the 2001 outbreak of FMD, the movement of cattle, sheep and other livestock was generally banned in an effort to prevent the spread of infection. Similarly in 2007, an outbreak of bluetongue virus lead to large-scale movement bans across eastern England.Given that the livestock industry relies on the movement of animals (between farms or farm to slaughter) to make a profit, such movement bans can have a profound and wide ranging impact on farmers. Moreover, in 2001 the general message that "the countryside is closed" resulted in enormous losses to the tourist industry.The research, "The Role of Movement Restrictions in Limiting the Economic Impact of livestock Infections" and published today (19 August 2019) by Nature Sustainability, found that the current UK government policy of national movement bans when an outbreak FMD is detected (and large-radius bans for BTV) may cause unnecessary economic harm, when a more localised movement ban could be as successful in halting the spread of the disease and would limit the subsequent negative economic impact.Led by Dr Mike Tildesley, of Warwick's Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research (SBIDER), the researchers use state of the art predictive models to examine the consequences of different control options.The researchers argue that whilst livestock movements bring the risk of long-range spread of infection, this risk is strongest from farms in close proximity to where infections has been detected; therefore a limited movement ban (only preventing movements from farms near to known cases) brings most of the benefits but less of the economic costs.By not automatically implemented national bans during FMD or BTV outbreaks, geographical regions unaffected by the outbreak would not face the same economic impact caused by the restrictions put in place by a national ban.Accordingly, whilst a national ban on livestock movement was an appropriate initial response to the FMD outbreak of 2001 given its widely dispersed nature, the policy caused potentially avoidable economic harm in the outbreak of 2007.Commenting on the research Dr Tildesley says:"Our research says that movement controls need to be carefully matched to both the epidemiological and economic consequences of the disease, and optimal movement bans are often far shorter than existing policy."For example, our work suggests that movement bans of between 15-60km are optimal for FMD (with larger radii preferable if tourism losses can be ignored), while for BTV the optimal policy is to allow all movements""Adopting these optimal movement bans could lead to vast savings compared to more stringent policies. We fully recognise the need for the government to rapidly contain novel outbreaks in the face of uncertainty, but our work suggests that optimal movement bans should be enacted as soon as possible."The researchers also looked at bovine tuberculosis (bTB), concluding that the economic cost of any movement ban is more than the epidemiological benefits; however if tests are sufficiently cheap a localised testing program around infected farms could be economically viable in the long-term.
|
Agriculture & Food
| 2,019 |
August 16, 2019
|
https://www.sciencedaily.com/releases/2019/08/190816075543.htm
|
Discovery of a bottleneck relief in photosynthesis may have a major impact on food crops
|
Scientists have found how to relieve a bottleneck in the process by which plants transform sunlight into food, which may lead to an increase in crop production. They discovered that producing more of a protein that controls the rate in which electrons flow during photosynthesis, accelerates the whole process.
|
"We tested the effect of increasing the production of the Rieske FeS protein, and found it increases photosynthesis by 10 percent," said lead researcher Dr Maria Ermakova from the ARC Centre of Excellence for Translational Photosynthesis (CoETP)."The Rieske FeS protein belongs to a complex which is like a hose through which electrons flow, so the energy can be used by the carbon engine of the plant. By overexpressing this protein, we have discovered how to release the pressure of the hose, so more electrons can flow, accelerating the photosynthetic process," said Dr Ermakova, who works at The Australian National University (ANU) Centre Node.Dr Ermakova, the lead author of the paper published this week in the journal Until now, the majority of efforts to improve photosynthesis have been done in species that use C3 photosynthesis, such as wheat and rice, but not a lot has been done in enhancing C4 photosynthesis.This is despite the fact that C4 crop species -- like maize and sorghum -- play a key role in world agriculture, and are already some of the most productive crops in the world."These results demonstrate that changing the rate of electron transport enhances photosynthesis in the C4 model species, Setaria viridis, a close relative of maize and sorghum. It is an important proof of concept that helps us enormously to understand more about how C4 photosynthesis works," said CoETP's Deputy Director Professor Susanne von Caemmerer, one of the co-authors of this study.The Rieske protein is particularly important in environments with high radiance, where C4 plants grow. Previous research has shown that overexpressing the Rieske protein in C3 plants improves photosynthesis, but more research was needed in C4 plants."It is really exciting, as we are now ready to transform this into sorghum and test the effect it has on biomass in a food crop," Professor von Caemmerer says.The research is the result of an international collaboration with researchers from the University of Essex in the UK, who are part of the Realizing Increased Photosynthetic Efficiency (RIPE) project."This is a great example that we need international collaborations to solve the complex challenges faced in trying to improve crop production," said University of Essex researcher Patricia Lopez-Calcagno, who was involved in producing some of the essential genetic components for the plant transformation."In the last 30 years, we have learnt a lot about how C4 plants work by making them worse -- by breaking them as part of the process of discovery. However, this is the first example in which we have actually improved the plants," says Professor Robert Furbank, Director of the ARC Centre of Excellence for Translational Photosynthesis and one of the authors of the study."Our next steps are to assemble the whole protein FeS complex, which has many other components. There is a lot more to do and lots of things about this protein complex we still don't understand. We have reached 10 percent enhancement by overexpressing the Rieske FeS component, but we know we can do better than that," says Professor Furbank.This research has been funded by the ARC Centre of Excellence for Translational Photosynthesis, which aims to improve the process of photosynthesis to increase the production of major food crops such as sorghum, wheat and rice.
|
Agriculture & Food
| 2,019 |
August 16, 2019
|
https://www.sciencedaily.com/releases/2019/08/190816075540.htm
|
Could biological clocks in plants set the time for crop spraying?
|
Dr Antony Dodd, Senior Lecturer in the School of Biological Sciences and senior author of the paper, said: "This proof of concept research suggests that, in future, we might be able to refine the use of some chemicals that are used in agriculture by taking advantage of the biological clock in plants. Approaches of this type, combining biotechnology with precision agriculture, can provide economic and environmental benefits."
|
Just like human jet lag, plants have body clocks that are crucial for their life in a world that has day and night. Plant biological clocks make a crucial contribution to their growth and the responses of crops to their fluctuating environments.In a new paper, published today [Friday 16 August] in the journal Crucially, the biological clock also led to a daily change in the minimum amount of herbicide that is needed to affect the plant, so less herbicide was needed at certain times of day. This provides an opportunity to reduce the quantity of herbicides used, saving farmers time, money and reducing environmental impacts.In medicine, "chronotherapy" considers the body clock when deciding the best time to give a medicine or treatment. This new research suggests that a similar approach could be adopted for future agricultural practice, with crop treatments being applied at times that are most appropriate for certain species of weed or crop. By employing a form of agricultural chronotherapy might have a future role in the sustainable intensification of agriculture required to feed the growing population.
|
Agriculture & Food
| 2,019 |
August 16, 2019
|
https://www.sciencedaily.com/releases/2019/08/190816075538.htm
|
New insight into bacterial infections found in the noses of healthy cattle
|
New research led by academics at the University of Bristol Veterinary and Medical Schools used the 'One Health' approach to study three bacterial species in the noses of young cattle and found the carriage of the bacteria was surprisingly different. The findings which combined ideas and methods from both animal and human health research could help prevent and control respiratory diseases.
|
Cattle, like humans, harbour a wide range of bacteria in their noses, microbes which are normally present and probably necessary for health like those that live in the gut. However, some species of these bacteria do cause serious illness at times, particularly when infection becomes established in the lower respiratory tract within the lungs.In an open access paper published in The research team took nasal swabs at intervals during the first year of life, to detect their presence and measure their abundance using a DNA-detection technique called quantitative polymerase chain reaction (qPCR) that targeted genes found in three bacterial species well-known for their ability to cause respiratory disease in cattle: Histophilus somni, Mannheimia haemolytica and Pasteurella multocida.The researchers found the carriage patterns of the three bacteria differed remarkably. Pasteurella was found in most of the animals, large numbers of bacteria were usually present, and the bacteria stayed in the nose for weeks or months. Histophilus was present in up to half the animals, usually in smaller numbers and the periods it was present were shorter. Mannheimia was rarely found although the numbers detected, when present, varied widely.These differences are of interest because the numbers of bacteria and their duration of carriage are likely to influence their spread among healthy cattle and the likelihood of causing severe respiratory disease.Amy Thomas, lead author who carried out the research as part of her PhD studies in Clinical Veterinary Science, said: "These techniques and results offer a way forward in understanding why and how apparently healthy cattle harbouring these bacteria may go on to develop respiratory illness and should help in finding new ways to prevent it."Professor Mark Eisler, co-author and Chair in Global Farm Animal Health at the Bristol Vet School, added: "These studies are particularly important because cattle are known to contribute to greenhouse gas emissions and improving how their diseases are controlled will help mitigate climate change. Also, reducing the use of antimicrobials that treat respiratory diseases in cattle should help reduce the increasing global threat of antimicrobial resistance in animals and humans."
|
Agriculture & Food
| 2,019 |
August 15, 2019
|
https://www.sciencedaily.com/releases/2019/08/190815212756.htm
|
Ancient feces reveal how 'marsh diet' left Bronze Age Fen folk infected with parasites
|
New research published today in the journal
|
The Bronze Age settlement at Must Farm, located near what is now the fenland city of Peterborough, consisted of wooden houses built on stilts above the water. Wooden causeways connected islands in the marsh, and dugout canoes were used to travel along water channels.The village burnt down in a catastrophic fire around 3,000 years ago, with artefacts from the houses preserved in mud below the waterline, including food, cloth, and jewellery. The site has been called "Britain's Pompeii."Also preserved in the surrounding mud were waterlogged "coprolites" -- pieces of human faeces -- that have now been collected and analysed by archaeologists at the University of Cambridge. They used microscopy techniques to detect ancient parasite eggs within the faeces and surrounding sediment.Very little is known about the intestinal diseases of Bronze Age Britain. The one previous study, of a farming village in Somerset, found evidence of roundworm and whipworm: parasites spread through contamination of food by human faeces.The ancient excrement of the Anglian marshes tells a different story. "We have found the earliest evidence for fish tapeworm, "These parasites are spread by eating raw aquatic animals such as fish, amphibians and molluscs. Living over slow-moving water may have protected the inhabitants from some parasites, but put them at risk of others if they ate fish or frogs."Disposal of human and animal waste into the water around the settlement likely prevented direct faecal pollution of the fenlanders' food, and so prevented infection from roundworm -- the eggs of which have been found at Bronze Age sites across Europe.However, water in the fens would have been quite stagnant, due in part to thick reed beds, leaving waste accumulating in the surrounding channels. Researchers say this likely provided fertile ground for other parasites to infect local wildlife, which -- if eaten raw or poorly cooked -- then spread to village residents."The dumping of excrement into the freshwater channel in which the settlement was built, and consumption of aquatic organisms from the surrounding area, created an ideal nexus for infection with various species of intestinal parasite," said study first author Marissa Ledger, also from Cambridge's Department of Archaeology.Fish tapeworms can reach 10m in length, and live coiled up in the intestines. Heavy infection can lead to anemia. Giant kidney worms can reach up to a metre in length. They gradually destroy the organ as they become larger, leading to kidney failure. "As writing was only introduced to Britain centuries later with the Romans, these people were unable to record what happened to them during their lives. This research enables us for the first time to clearly understand the infectious diseases experienced by prehistoric people living in the Fens," said Ledger.The Cambridge team worked with colleagues at the University of Bristol's Organic Chemistry Unit to determine whether coprolites excavated from around the houses were human or animal. While some were human, others were from dogs."Both humans and dogs were infected by similar parasitic worms, which suggests the humans were sharing their food or leftovers with their dogs," said Ledger.Other parasites that infect animals were also found at the site, including pig whipworm and The researchers compared their latest data with previous studies on ancient parasites from both the Bronze Age and Neolithic. Must Farm tallies with the trend of fewer parasite species found at Bronze Age compared with Neolithic sites."Our study fits with the broader pattern of a shrinking of the parasite ecosystem through time," said Mitchell. "Changes in diet, sanitation and human-animal relationships over millennia have affected rates of parasitic infection." Although he points out that infections from the fish tapeworm found at Must Farm have seen a recent resurgence due to the popularity of sushi, smoked salmon and ceviche."We now need to study other sites in prehistoric Britain where people lived different lifestyles, to help us understand how our ancestors' way of life affected their risk of developing infectious diseases," added Mitchell.The Must Farm site is an exceptionally well-preserved settlement dating to 900-800 BC (the Late Bronze Age). The site was first discovered in 1999. The Cambridge Archaeological Unit carried out a major excavation between 2015 and 2016, funded by Historic England and Forterra Building Products Ltd.
|
Agriculture & Food
| 2,019 |
August 15, 2019
|
https://www.sciencedaily.com/releases/2019/08/190815113723.htm
|
Discovery could pave the way for disease-resistant rice crops
|
Researchers have uncovered an unusual protein activity in rice that can be exploited to give crops an edge in the evolutionary arms race against rice blast disease, a major threat to rice production around the world.
|
Magnaporthe oryzae, the fungus that leads to rice blast disease, creates lesions on rice plants that reduce the yield and quality of grain. The fungus causes a loss of up to a third of the global rice harvest, roughly enough to feed more than 60 million people each year.Various strategies to ward off the fungus have been employed, but a sustainable approach has not yet been developed. Cost and environmental concerns have limited the success of toxic fungicides. And a phenomena called linkage drag, where undesirable genes are transferred along with desired ones, has made it difficult for breeders to produce varieties of rice that exhibit improved disease resistance but still produce grain at a desired rate.Gene-editing technologies could eventually be used to precisely insert genes in rice plants, overcoming the issue of linkage drag, but first, genes that boost rice immunity need to be identified or engineered.A team of researchers in Japan and the U.K. report in the Rice blast fungus deploys a multitude of proteins, known as effectors, inside of rice cells. In response, rice plants have evolved genes encoding nucleotide binding-leucine-rich repeat proteins, or NLRs, which are intracellular immune receptors that bait specific fungal effectors. After an NLR receptor's specific fungal effector binds to the bait, signaling pathways are initiated that cause cell death."(The cells) die in a very localized area so the rest of the plant is able to survive. It's almost like sacrificing your finger to save the rest of your body," said Mark Banfield, professor and group leader at John Innes Centre in Norwich, England, and senior author of the study.After learning from previous work that the fungal effectors AVR-Pia and AVR-Pik have similar structures, the researchers sought to find out whether any rice NLRs known to bind to one of these effectors could perhaps also bind to the other, Banfield said.The scientists introduced different combinations of rice NLRs and fungal effectors into tobacco (a model system for studying plant immunity) and also used rice plants to show if any unusual pairs could come together and elicit immune responses. An AVR-Pik-binding rice NLR called Pikp triggered cell-death in response to AVR-Pik as expected, but surprisingly, the experiments showed that plants expressing this NLR also partially reacted to AVR-Pia.The authors took a close look at the unexpected pairing using X-ray crystallography and noticed that the rice NLR possessed two separate docking sites for AVR-Pia and AVR-Pik.In its current form, Pikp causes meager immune reactions after binding AVR-Pia, however, the receptor's DNA could be modified to improve its affinity for mismatched effectors, Banfield said."If we can find a way to harness that capability, we could produce a super NLR that's able to bind multiple pathogen effectors," Banfield said.As an ultimate endgame, gene-editing technologies could be used to insert enhanced versions of NLRs -- like Pikp -- into plants, Banfield said, which could tip the scale in favor of rice crops in the face of rice blast disease.This work was supported by Biotechnology and Biological Sciences Research Council, grant numbers BB/P012574, BB/M02198X; the ERC (proposal 743165), the John Innes Foundation, the Gatsby Charitable Foundation and JSPS KAKENHI 15H05779 and 18K05657.Other authors on this study include Freya A. Varden, Hiromasa Saitoh, Kae Yoshino, Marina Franceschetti, Sophien Kamoun and Ryohei Terauchi.
|
Agriculture & Food
| 2,019 |
August 15, 2019
|
https://www.sciencedaily.com/releases/2019/08/190815101535.htm
|
Green chemists find a way to turn cashew nut shells into sunscreen
|
A team of international scientists has found an environmentally friendly way of producing potential sunscreens by using cashew nut shells, a waste material.
|
The team of "green chemists" from the University of the Witwatersrand, along with colleagues from Universities in Germany, Malawi and Tanzania, are working on techniques to produce useful compounds from wood and other fast growing non-edible plant waste, through a chemical process named xylochemistry (wood chemistry). By using cashew nut shells, the team has produced new aromatic compounds that show good UVA and UVB absorbance, which may be applied to protect humans, livestock, as well as polymers or coatings from harmful rays from the sun. The research has just been published as the cover article of the UV rays are damaging to most materials, with its effects leading to the discoloration of dyes and pigments, weathering, yellowing of plastics, loss of gloss and mechanical properties, while it can lead to sunburn, premature aging and even the development of potentially lethal melanomas in both humans and animals.To mitigate UV damage, both organic and inorganic compounds are used as UV filters. Ideal organic UV filters display a high UV absorption of UVA rays (in the region ranging from 315-400 nm) and UVB rays (280-315 nm). One important family of UV absorber molecules are derived from aromatic compounds known as phenols, which contain a hydrogen-bonded hydroxyl group that plays an important role in the dissipation of the absorbed energy.For example, an organic compound known as oxybenzone is a common ingredient that has also been added to plastics to limit UV degradation. Apart from their petrochemical origin, a major drawback of current UV protection agents is their negative effect on aquatic ecosystems associated with a poor biodegradability.As a result, there is growing attention from regulatory bodies and stricter regulations are being enforced on the production of sun filtering products."With the current concerns over the use of fossil resources for chemical synthesis of functional molecules and the effect of current UV absorbers in sunscreens on the ecosystem, we aimed to find a way to produce new UV absorbers from cashew nut shell liquid (CNSL) as a non-edible, bio renewable carbon resource," says Professor Charles de Koning, of the Wits School of Chemistry and principal author of the paper, together with Till Opatz from Johannes Gutenberg University in Mainz, Germany."Cashew nut shells are a waste product in the cashew-farming community, especially in Tanzania, so finding a useful, sustainable way to use these waste products can lead to completely new, environmentally friendly ways of doing things."The team has already filed a patent application in order to commercialise the process in South Africa.
|
Agriculture & Food
| 2,019 |
August 14, 2019
|
https://www.sciencedaily.com/releases/2019/08/190814161818.htm
|
Compost key to sequestering carbon in the soil
|
By moving beyond the surface level and literally digging deep, scientists at the University of California, Davis, found that compost is a key to storing carbon in semi-arid cropland soils, a strategy for offsetting CO
|
For their 19-year study, published in the journal "If we take the time and energy to look a little deeper, there's always more to the story," said co-first author Jessica Chiartas, a Ph.D. student with the UC Davis land, air and water resources department. "The soil represents a huge mass of natural resource under our feet. If we're only thinking about farming the surface of it, we're missing an opportunity. Carbon is like a second crop."Nationwide, many studies that investigated carbon change in the top foot of soil found that cover-cropped systems store carbon. The UC Davis study also found gains in the surface but, deeper down, enough carbon was released from cover-cropped systems that it resulted in an overall net loss."There are other benefits to cover crops that farmers may still enjoy, but in our systems, storing carbon is not necessarily one of them," said co-first author Nicole Tautges, a cropping systems scientist with the UC Davis Agricultural Sustainability Institute. "We'd make more progress by incentivizing compost."The researchers did not compare composted systems without cover crops, but suspect the compost helped sequester carbon despite the cover crop, a notion they intend to investigate further.Carbon has to filter through soil microbes to create stabilized forms of carbon in soil. Compost provides not only carbon but also additional vital nutrients for those microbes to function effectively."One reason we keep losing organic matter from soils is that our focus is on feeding the plant, and we forget the needs of others who provide important services in soil like building organic carbon," said senior author Kate Scow, director of the UC Davis Russell Ranch Sustainable Agriculture Facility. "We need to feed the soil, too."Having a balanced diet can make the difference between how much carbon stays in the soil versus how much is released as carbon dioxide, Scow said.When their diet is out of balance, microbes seek out missing nutrients, mining them from existing soil organic matter. This results in the loss rather than gain of carbon. The authors think that deep in the soil, cover-crop roots provided carbon but not the other nutrients needed to stabilize it.The study was conducted in California's northern Central Valley at the Russell Ranch Sustainable Agriculture Facility, part of the Agricultural Sustainability Institute at UC Davis. The results indicate that semi-arid Mediterranean climates like the study site may be capable of storing far more carbon in the soil than once thought possible."This work coming out of Russell Ranch at UC Davis is very timely as the state invests in programs to sequester carbon in soils," said Secretary Karen Ross of the California Department of Food and Agriculture. "Carbon sequestration in soils through the addition of compost is a key practice in our Healthy Soils Program and we are delighted that the science and policy efforts are aligning and supporting each other."The results also indicate an opportunity for compost to provide multiple, interconnected benefits to farmers and the environment by improving soils, offsetting greenhouse gas emissions, and transforming animal and food wastes into a valuable product the soil needs.Additional study co-authors include Amé?lie Gaudin, Anthony O'Geen and Israel Herrera from UC Davis.The study was supported by funding from the USDA National Institute of Food and Agriculture and the UC Davis College of Agricultural and Environmental Sciences.
|
Agriculture & Food
| 2,019 |
August 12, 2019
|
https://www.sciencedaily.com/releases/2019/08/190812172326.htm
|
Asian longhorned beetle larvae eat plant tissues that their parents cannot
|
Despite the buzz in recent years about other invasive insects that pose an even larger threat to agriculture and trees -- such as the spotted lanternfly, the stink bug and the emerald ash borer -- Penn State researchers have continued to study another damaging pest, the Asian longhorned beetle.
|
Their most recent research revealed that the larval offspring of the wood-borer native to China can feed and thrive on tree species whose tissues would sicken their parents, perhaps explaining how the beetle expands its range, even when its preferred host trees -- maples, elms and willows -- are not nearby. cut log with insect tunnelingThe researchers' attention on Asian longhorned beetles remains well-placed because the U.S. Department of Agriculture's Animal and Plant Health Inspection Service has spent approximately $640 million to eradicate outbreaks of the wood-boring beetle in Illinois, New Jersey, New York and Massachusetts. And eradication efforts continue in New York, Massachusetts and Ohio.The Asian longhorned beetle most likely came to the United States inside wood packaging material from Asia in the early 1990s, according to Kelli Hoover, professor of entomology. Her research group in the College of Agricultural Sciences has been studying the pest for 19 years."In North America, the beetle attacks and can kill dozens of species from 15 plant families," she said. "Northern hardwood forests reaching from the Atlantic Ocean to the Great Lakes and beyond are made up of vulnerable species -- approximately 48 million acres in the United States, plus the majority of Canada's hardwood forests."This is not a new pest, but it still threatens billions of dollars in economic damage, Hoover pointed out, adding that if USDA had not undertaken its eradication efforts, Asian longhorned beetles would be causing a tremendous amount of damage over a much larger area."Those eradication efforts will have to continue," she said. poster showing an Asian longhorn beetle under a magnifying glassSome trees, such as poplar, have limited resistance to attacks by Asian longhorned beetles, noted lead researcher Charlie Mason, postdoctoral scholar in entomology. In trying to assess the difference in resistance between Chinese poplar and native poplar -- which consists of trees secreting compounds into their bark and wood tissues making them unpalatable to the wood-boring beetles -- the researchers made a startling discovery: Larval Asian longhorned beetles can consume tree tissues that the adults cannot.In their study, researchers realized that different plant species had strong effects on adult performance, but these patterns did not extend to effects on juveniles consuming the same hosts. They saw that female adult beetles were capable of producing eggs when feeding on red maple, but not when provided eastern cottonwood, also called necklace poplar, or Chinese white poplar.Yet females that produced eggs by feeding on red maple deposited eggs into all three plant species and the larvae that hatched from these eggs performed equally on the three hosts. The differences between adult and juvenile utilization of poplar was very different."That is because poplar has markedly higher salicinoid phenolic concentrations in bark, which discourage adult Asian longhorned beetles from feeding, while poplar wood had only trace amounts," said Mason. "The tree's resistance is due to compounds present in the bark that make it unpalatable for adults."But the adult female cuts a small notch in the bark and deposits her eggs, and the hatched larvae from there are able to tunnel into the wood tissues and be nourished by eating them, avoiding having to feed on bark.By feeding on the wood and burrowing through tree limbs, making them weak, unstable and liable at any time to collapse on people below, Asian longhorned beetle have wreaked havoc on trees in urban areas such as New York City, Worcester, Massachusetts, and Chicago. The damage they caused has resulted in the removal of thousands of infested trees.This research, recently published in the "Now we know that the host range is not equal between adults and larvae," she said. "The young ones appear to have a broader range of trees they can feed on because they can avoid the toxic chemicals in the bark."Also involved in the research were David Long, Penn State research technologist in entomology, and Richard Lindroth, professor of ecology in the Department of Entomology, University of Wisconsin-Madison.The U.S. Department of Agriculture's National Institute of Food and Agriculture and the Alphawood Foundation funded this research.
|
Agriculture & Food
| 2,019 |
August 12, 2019
|
https://www.sciencedaily.com/releases/2019/08/190812130827.htm
|
Artificial intelligence helps banana growers protect the world's most favorite fruit
|
Artificial intelligence-powered tools are rapidly becoming more accessible, including for people in the more remote corners of the globe. This is good news for smallholder farmers, who can use handheld technologies to run their farms more efficiently, linking them to markets, extension workers, satellite images, and climate information. The technology is also becoming a first line of defense against crop diseases and pests that can potentially destroy their harvests.
|
A new smartphone tool developed for banana farmers scans plants for signs of five major diseases and one common pest. In testing in Colombia, the Democratic Republic of the Congo, India, Benin, China, and Uganda, the tool provided a 90 percent successful detection rate. This work is a step towards creating a satellite-powered, globally connected network to control disease and pest outbreaks, say the researchers who developed the technology. The findings were published this week in the journal "Farmers around the world struggle to defend their crops from pests and diseases," said Michael Selvaraj, the lead author, who developed the tool with colleagues from Bioversity International in Africa. "There is very little data on banana pests and diseases for low-income countries, but an AI tool such as this one offers an opportunity to improve crop surveillance, fast-track control and mitigation efforts, and help farmers to prevent production losses."Co-authors included researchers from India's Imayam Institute of Agriculture and Technology (IIAT), and Texas A&M University.Bananas are the world's most popular fruit and with the global population set to reach 10 billion in 2050, pressure is mounting to produce sufficient food. Many countries will continue depending on international trade to ensure their food security. It is estimated that by 2050 developing countries' net imports of cereals will more than double from 135 million metric tonnes in 2008/09 to 300 million in 2050. An essential staple food for many families, bananas are a crucial source of nutrition and income. However, pests and diseases -- Xanthomanas wilt of banana, Fusarium wilt, black leaf streak (or Black sigatoka), to name a few -- threaten to damage the fruit. And when a disease outbreak hits, the effects to smallholder livelihoods can be detrimental.In the few instances in which losses to the Fusarium Tropical race 4 fungus have been estimated, they amounted to US$121 million in Indonesia, US$253.3 million in Taiwan, and US$14.1 million in Malaysia (Aquino, Bandoles and Lim, 2013). In Africa, where the fungus was first reported in 2013 in a plantation in northern Mozambique, the number of symptomatic plants rose to more than 570,000 in September 2015.The tool is built into an app called Tumaini -- which means "hope" in Swahili -- and is designed to help smallholder banana growers quickly detect a disease or pest and prevent a wide outbreak from happening. The app aims to link them to extension workers to quickly stem the outbreak. It can also upload data to a global system for large-scale monitoring and control. The app's goal is to facilitate a robust and easily deployable response to support banana farmers in need of crop disease control."The overall high accuracy rates obtained while testing the beta version of the app show that Tumaini has what it takes to become a very useful early disease and pest detection tool," said Guy Blomme, from Bioversity International. "It has great potential for eventual integration into a fully automated mobile app that integrates drone and satellite imagery to help millions of banana farmers in low-income countries have just-in-time access to information on crop diseases."Rapid improvements in image-recognition technology made the Tumaini app possible. To build it, researchers uploaded 20,000 images that depicted various visible banana disease and pest symptoms. With this information, the app scans photos of parts of the fruit, bunch, or plant to determine the nature of the disease or pest. It then provides the steps necessary to address the specific disease. In addition, the app also records the data, including geographic location, and feeds it into a larger database.Existing crop disease detection models focus primarily on leaf symptoms and can only accurately function when pictures contain detached leaves on a plain background. The novelty in this app is that it can detect symptoms on any part of the crop, and is trained to be capable of reading images of lower quality, inclusive of background noise, like other plants or leaves, to maximize accuracy."This is not just an app," said Selvaraj. "But a tool that contributes to an early warning system that supports farmers directly, enabling better crop protection and development and decision making to address food security."This study, implemented by the Alliance between Bioversity International and the International Center for Tropical Agriculture (CIAT), has shown the potential of cutting-edge technologies such as AI, IoT (Internet of Things), robotics, satellites, cloud computing, and machine learning for the transformation of agriculture and for helping farmers.
|
Agriculture & Food
| 2,019 |
August 12, 2019
|
https://www.sciencedaily.com/releases/2019/08/190812104757.htm
|
Scent brings all the songbirds to the yard
|
Chickadees can smell! That is the news from a study out of Lehigh University, the first to document naturally hybridizing songbirds' preference for the scent of their own species.
|
Amber Rice, an evolutionary biologist at Lehigh, studies natural hybridization-when separate species come into contact and mate-to better understand how species originate and how existing species are maintained. The two species that make up the hybridized population she studies are the black-capped chickadee and its relative the Carolina chickadee.Rice and Ph.D. student, Alex Van Huynh, set out to test the potential for scent to act as a mate choice cue, contributing to reproductive isolation between the black-capped and Carolina chickadees who live in the "hybrid zone" in the eastern Pennsylvania region where Lehigh is located.Huynh and Rice found that both black-capped and Carolina chickadees produce chemically distinct natural oils. Testing both males and females of both chickadee species, they found that males and females prefer the smell of their own species over the smell of the opposite species. These preferences could be impacting hybridization. Their results have been published in an article entitled: "Conspecific olfactory preferences and interspecific divergence in odor cues in a chickadee hybrid zone" in "The sense of smell has been very understudied in birds, particularly songbirds, because they frequently have such impressive plumage and song variation," says Rice. "Some other recent work has documented that species of songbird can smell and prefer their species' odors, but this is the first example in currently hybridizing species that we know of.""Our results show that not only can odor cues be used by songbirds, potentially as a mate choice cue, but that they can have ecological and evolutionary consequences for songbird species," adds Huynh.The black-capped and Carolina chickadees interbreed with one another, but their hybrid offspring suffer fitness costs. For example, the interbred chickadees are less likely to hatch from their eggs, and they have lower cognitive abilities than pure-species birds.Interestingly, the researchers found that the chickadees they studied do not actively avoid the smell of the other species."This fact may be coincident with the observation that hybridization still does indeed take place," says Huynh. "We know the hybrid zone is very small and its width is stable over time. In other words, the geographic area of hybridization is not growing or shrinking."Huynh and Rice caught wild birds from hybrid zone populations in Pennsylvania. They used gas-chromatography mass-spectrometry to analyze differences between the species in the natural oils the birds produce from their uropygial glands (also known as the preen glands). They tested for the species' odor preference using a Y-maze, measuring the amount of time a bird spends with a particular smell.The experiments indicated a clear preference for same-species whole-body odors in both species of chickadees. These preferences were present in both male and female birds. The results, the team says, are consistent with a possible role for olfactory signaling in premating reproductive isolation in chickadees."Within the hybrid zone, the two species show differences in their uropygial oil chemistry as well as significant preferences for their own species over those of the other species," says Rice.The team believes that researchers in the fields of animal behavior and chemical ecology will find their study particularly interesting. Investigating odor in future studies of songbird behavior such as mate choice, predation risk assessment, or competitive interactions, are some promising avenues for future inquiry.The research was supported by Lehigh University and the National Science Foundation, as well as research grants from the Society for the Study of Evolution (The Rosemary Grant Award) and the Animal Behavior Society.
|
Agriculture & Food
| 2,019 |
August 12, 2019
|
https://www.sciencedaily.com/releases/2019/08/190812102853.htm
|
Diet change needed to save vast areas of tropics
|
One quarter of the world's tropical land could disappear by the end of the century unless meat and dairy consumption falls, researchers have warned.
|
If the global demand for animal products continues to grow, large swathes of natural land will vanish potentially leading to widespread loss of species and their habitats.Some nine per cent of natural land -- 95 per cent of which is in the tropics -- could go within 80 years unless global dietary habits change, the scientists say.Researchers at the University of Edinburgh and Karlsruhe Institute of Technology studied the impact of consumption trends on biodiverse regions -- areas that have a wealth of mammals, birds, amphibians and plant life.They found that rapid increases in meat and milk production result in sharp rises in land clearing in tropical regions that harbour high levels of biodiversity.As incomes increase across the globe, consumption has shifted from staples such as starchy roots and pulses to meat, milk, and refined sugars.Meat and dairy production is associated with higher land and water use and higher greenhouse gas emissions than any other foods.By replacing animal products with plant-based alternatives, they predict that the global demand for agricultural land could be reduced by 11 per cent.Researchers also found that industrial feed systems reduce agricultural expansion but may increase environmental degradation due to agricultural pollutants such as fertiliser.The study comes after the Intergovernmental Panel on Climate Change last week published a special report that identified reducing meat consumption as an important focus for climate change mitigation.Lead author Dr Roslyn Henry, said, "Reducing meat and dairy consumption will have positive effects on greenhouse gas emissions and human health. It will also help biodiversity, which must be conserved to ensure the world's growing population is fed. Changing our diets will lead to a more sustainable future and complement food security goals while addressing global food inequalities."
|
Agriculture & Food
| 2,019 |
August 8, 2019
|
https://www.sciencedaily.com/releases/2019/08/190808123853.htm
|
Novel strategy uncovers potential to control widespread soilborne pathogens
|
Soilborne pathogens are a major issue worldwide as they can infect a broad range of agricultural plants, resulting in serious crop losses devastating to farmers. These persistent pathogens are often resistant toward chemical fungicides, making them difficult to control, and have a broad host range, enabling them to damage a variety of important crops.
|
Some of these pathogens have the ability to form survival bodies called sclerotia that can survive for many years in the soil before they cause infection and disease in new plant generations. Other microorganisms often form stable associations with these sclerotia, resulting in a complex system teeming with fungal pathogens and non-pathogenic bacteria.A team of scientists based in Austria and Germany analyzed the microorganisms within the sclerotia of soilborne fungal pathogens from genera Rhizoctonia and Sclerotinia in attempt to discover effective control methods. In these microorganisms, the team found specific bacterial communities different from both the surrounding soil and the host plants affected by the pathogens.They extracted samples from these communities and through additional analysis discovered that several of the bacteria can produce volatile compounds (small chemicals that easily disperse) with the potential to reduce the viability of the pathogens. The team also found that specific combinations of these bacteria can even more effectively counteract the pathogens.This study, published in the completely open access Also of note, this study "shows how a multi-phasic approach combining different disciplines (microbiology, molecular biology and analytical chemistry) can be implemented to find new solutions for plant protection," according to co-author Tomislav Cernava.
|
Agriculture & Food
| 2,019 |
August 8, 2019
|
https://www.sciencedaily.com/releases/2019/08/190808123845.htm
|
Where are the bees? Tracking down which flowers they pollinate
|
Bees are in vast decline in the UK and across Europe, as are the wildflowers on which they rely. Bees have an essential role in our ecosystems and a third of all our food is dependent on their pollination; just in economic worth, pollination by bees is annually estimated at £265 billion, worldwide.
|
The main risks to bees include wide-spread pesticide use in agriculture, parasites, disease and climate change, and crucially -- the loss of valuable biodiversity which poses a further threat to bees and other wild pollinators. One way to help boost their numbers is by planting the correct wildflowers, providing a better habitat for pollinators to disperse, nest and breed.However, it is unclear which plant species are the most preferred between different pollinators, including bees, and how this might change over time and in different environmental conditions. In agriculture, farmers want to know that the pollinators are actually visiting the plants they need them to. Historically, scientists used light microscopy to identify individual bee-collected pollen grains, which was a time-consuming and impractical method.To obtain a more accurate understanding without the need for laborious manual inspection of pollen, scientists have developed a rapid analysis method called 'Reverse Metagenomics' (RevMet) that can identify the plants that individual bees visit using the MinION, a portable DNA sequencer from Oxford Nanopore Technologies.The portability of the equipment involved means that this type of analysis could be performed on-site where bees are collected and sampled -- vastly increasing our understanding of where bees look for pollen on a national scale.Ned Peel, the PhD student who carried out the research in the Leggett Group at EI: "Importantly, from a mixed sample of pollen, as well as being able to work out what species of plant bees have visited, we can also measure the relative quantities of each type of pollen. This type of analysis can be applied not only to conserving pollinators but to helping us to sustainably improve crop production that relies on pollinators."Previous costly and inefficient manual methods to measure pollen and other genomics methods, such as metabarcoding, have been developed -- but these can't accurately measure how much of each different type of pollen is found in a sample.Ned goes on to explain the new genomics method further: "In standard metagenomics, short stretches of DNA from mixed samples are compared to whole genomes, which can be expensive to generate. In collaboration with UEA's School of Biological Sciences, who performed the ecological side of the research -- collecting bees and plant samples -- we discovered that we could conduct the analysis using 'reference skims' instead."To make a skim, we carry out really cheap sequencing that only partially covers the complete genome of the plants, but this is enough when compared with the long reads from the MinION to identify plants. In our work, we generated skims of 49 different wild UK plant species."This technique can reliably differentiate species in a mixed sample according to the amount of DNA present of each. The results showed that honeybees, and two species of bumblebee, demonstrate a high preference for one plant species per foraging trip."The reverse metagenomics pipeline can be applied to more questions than just what plants bees like to pollinate; we can also understand whether certain wildflowers compete with agricultural flowers for pollinators, or the behaviour of pollinators across large areas and land types.The method could also be used to study other mixed samples, such as herbivore dung, for diet analysis; and air, to identify airborne allergenic pollen and crop pathogens.
|
Agriculture & Food
| 2,019 |
August 8, 2019
|
https://www.sciencedaily.com/releases/2019/08/190808115111.htm
|
Tobacco plant 'stickiness' aids helpful insects, plant health
|
Researchers at North Carolina State University have shown that "sticky" hairlike structures on tobacco leaves can help attract beneficial insects that scavenge on other insects trapped on the leaves, increasing leaf yield and reducing pest damage to plant structures.
|
In a study examining pests of tobacco plants and opportunistic insects that eat the pests, researchers show that sticky glandular trichomes on tobacco leaves trap insects that aren't adapted to interacting with perilous plant surfaces. The trapped insects perish and then become food for the spined stilt bug (Tobacco plants provide a trapped-insect buffet that spined stilt bugs are more than happy to feast upon, which helps protect the plant from pest infestation and damage. Better still, the spined stilt bug -- which uses its long legs as leverage to navigate across the sticky parts of tobacco leaves to reach its bug banquet -- isn't harmful to tobacco plants, researchers say, although it drinks some sap from tobacco plants to stay hydrated between pest meals."A sticky plant isn't a dead end for all insects; some actually prefer sticky plants and take advantage of the difficult plant surface," said Peter Nelson, an NC State Ph.D. graduate and lead author of a paper describing the study."By taking a closer look at how insects interact with plants, we might be able to take advantage of unique interactions for pest management," Nelson added. "Our review of the literature found that over 25 economically important plants have sticky surfaces that trap insects and might benefit from the same type of interaction with predatory arthropods.""This is a mutualistic relationship previously unrecognized on domesticated tobacco plants," said Clyde Sorenson, Alumni Association Distinguished Undergraduate Professor of Entomology at NC State and corresponding author of the paper. "The academic literature shows a number of wild flowers with similar symbiotic relationships with predators to reduce damage to the plant, but tobacco is the first economically important plant to show this mutualistic relationship."In the study, the abundance of spined stilt bugs grew when researchers added dead fruit flies (Drosophila melanogaster) to the leaves of tobacco plants in greenhouse and field settings. Increased leaf yield -- the primary economic consideration for tobacco farmers -- and less damage to tobacco plant structures resulted when additional fruit flies were added to leaves.The study also showed that insecticide use did not affect pest entrapment by sticky glandular trichomes. Plants treated with imidacloprid, a common tobacco insecticide, had fewer spined stilt bugs than untreated plants, but that did not significantly affect pest densities or plant health.Surprisingly, the study showed that densities of pests like the tobacco budworm on tobacco leaves did not decrease, even though more spined stilt bugs were present."We're not completely sure about why this counterintuitive finding occurred, although one hypothesis is that the increased number of predator stilt bugs may trigger a behavioral response in the tobacco budworm and other pests to feed less on tobacco plants," Sorenson said.Sorenson said the results could lead to further improvement or manipulation of glandular trichomes."We don't expect farmers to throw dead fruit flies on 40 acres of a tobacco crop, but recognizing the effects of beneficial insects and how these mutually beneficial relationships work is important," he said. "Plus, these types of effects may occur in other economically important crops with glandular trichomes, like tomatoes."
|
Agriculture & Food
| 2,019 |
August 8, 2019
|
https://www.sciencedaily.com/releases/2019/08/190808111427.htm
|
When invasive plants take root, native animals pay the price
|
Imagine a new breed of pirate not only able to sail the high seas, but to exploit nearly any mode of transportation without detection. And these raiders' ambitions have little to do with amassing treasure and everything to do with hijacking ecosystems.
|
Today's invasive species are as tenacious and resilient as the pirates of yesteryear, and when these plunderers set foot in new locations around the world, they know how to make themselves at home. As a result, home will never be the same for many native residents.Virginia Tech researchers have discovered that when invasive plants take root, native animals pay the price.Jacob Barney, associate professor in the College of Agriculture and Life Sciences' School of Plant and Environmental Sciences, graduate researcher Becky Fletcher, and a team of five other doctoral students conducted the first-ever comprehensive meta-analytic review examining the ecological impacts of invasive plants by exploring how animals -- indigenous and exotic -- respond to these nonnative plants. Their study, which took place over a two-year period, is published in the journal "Individual studies are system-specific, but we wanted to look for commonalities about how animals respond to invasive species. Our findings suggest that the impacts of invasive plants are much worse than we thought," said Barney. "Exotic animals' ability to survive on invasive plants coupled with the reduction of native animals is almost a worst-case scenario."The team's findings underscore the negative impact of invasive plant species on native animal populations -- populations that include worms, birds, and a host of mammals and other vertebrates -- all of whom serve a multitude of important ecosystem functions across a range of trophic levels. Only mollusks and arthropods were unaffected."We had reason to believe that native and exotic animals may respond differently to invasive plants," said Fletcher, a Kansas City native who is completing her doctorate in invasive plant ecology, and the paper's lead author. "We hypothesized that exotic plants may increase the abundance of exotic animals while reducing the abundance of native animals."As it turns out, invasive plants had no impact on the abundance of exotic animals. The plants do not facilitate exotic animals, nor do they harm them. In essence, nonnative flora provides sufficient nourishment and other benefits to uphold, if not to enlarge, nonnative animal populations. On the other hand, native animals are diminishing as invasive plants gain a foothold in their habitats.Gourav Sharma, Ariel Heminger, and Cody Dickinson hold an array of beautiful, though invasive, plant species, including Queen Anne's lace, spotted knapweed, butterfly bush, tree-of-heaven, Amur honeysuckle, Amur maple, and Japanese barberry. Collectively, invasive species -- plants, animals, and diseases -- cause an estimated $120 billion in damages each year."Invasive species are one of the five drivers of global change. Just as human-induced phenomena, such as land use disturbance, climate change, and disease, are re-shaping our ecosystems, the same is true for invasive plants and animals," said Barney, who is also a fellow in the Fralin Life Sciences Institute and an affiliate of the Global Change Center. "Our world will witness even more invasions over time. So, we must understand the body of research because it will drive conservation efforts."As a result of human activity, invasive plant and animal species now encircle the planet, colonizing terrestrial, aquatic, and marine environments, and suffusing every ocean and continent. In addition to their ability to displace native plants and animals, invasive species reduce wildlife habitat and alter natural processes. These environmental damages are often amplified by cascading impacts on other associated species and systems, including deforestation, storm water runoff, reduced groundwater, increased risk of wildfires, and the introduction of pathogens. Such sweeping losses also reap severe economic repercussions. While invasive insects cost the agricultural industry $13 billion in crops annually, collectively, invasive species -- plants, animals, and diseases -- cause an estimated $120 billion in damages each year in the United States alone.A worst-case scenario feared by some researchers is invasion meltdown, which hypothesizes that once an exotic species -- plant or animal -- becomes abundant in an area, the ecosystem may change in such a way that facilitates the establishment of additional invaders. While Barney's study was not designed to test invasion meltdown, the scenario is not so far-fetched."In the context of biodiversity, we are worried about the impact invasive species are having on diversity and ecosystems," said Fletcher.The researchers cite studies showing that native cardinals nesting in invasive Lonicera maackii shrubs fledged 20 percent fewer offspring. The team also discovered that animals in wet ecosystems were more impacted than in dry ecosystems. Rivers, already more nutrient-rich than terrestrial systems, are subject to frequent and intense disruptions such as flooding that can flow debris, seeds, and vegetation to new locales."As a result of climate change and land-use disturbance, species homogenization is the new normal," said Barney, pointing out another challenge for researchers. "So, identifying nativity, the place a plant or animal has long existed, is becoming much harder. We need to document what is native versus exotic in every system as this will better inform our understanding of the effects of invasive plants."This information, coupled with better taxonomic identification of the animals impacted by invasive plants, could shed light on whether invasive species are the arbiters of global change or merely the victims."For 20 years, I've conducted experiments on individual species to learn about them," said Barney. "This was the first time I've been able to do a large-scale study looking at big picture consequences. This approach was refreshing and allowed us to ask questions that have larger implications and look at larger trends. Working with six Ph.D. students was also a nice team effort. We coordinated well and approached this as a team of equals."
|
Agriculture & Food
| 2,019 |
August 7, 2019
|
https://www.sciencedaily.com/releases/2019/08/190807092333.htm
|
Cover crops, compost and carbon
|
Soil organic matter has long been known to benefit farmers. The carbon in this organic matter acts as a food source for soil microbes, which then provide other nutrients to the crops grown. Microbes, insects and small soil critters produce materials that can improve soil structure and water retention. It's a healthy ecosystem every farmer wants to encourage.
|
Measuring changes in soil organic matter can be a challenge in intensively tilled soil that is used for vegetable production. Even in production systems with less soil disturbance, soil organic matter changes slowly. But, Eric Brennan and Veronica Acosta-Martinez are testing for soil enzymes as early indicators of improvements in soil health in a long-term systems study.Brennan manages the study in an area of California known as the "Salad Bowl of the World." The Salinas Valley has high-input, organic vegetable production systems. "Farms in Salinas usually need to produce two or more vegetable crops per field annually to be profitable," says Brennan. "This production intensity complicates the adoption of winter cover cropping. This is why many farmers in this region prefer to use compost to add large amounts of organic matter to the soil."Specifically, the team compared farming systems that received different amounts and types of organic matter. The sources were from compost and cover crops. They recently published their results in the "Our results on soil enzyme activity illustrate the importance of frequent cover-cropping in tillage-intensive, organic vegetable production," says Brennan. "This raises questions about the sustainability of organic and conventional vegetable systems if cover crops are seldom used. We need to find innovative strategies to help farmers increase cover cropping. The practice is shown to improve soil health. It also provides other benefits like reducing nitrogen leaching into ground water."It's not that organic or conventional farmers in this region are against cover cropping. It's that their use can complicate many aspects of vegetable production.Brennan's study showed that cover cropping annually -- no matter the type of plant grown -- greatly benefits the soil. The study found that annual inputs of compost have relatively small benefits. There was an increase in microbial activity with compost, but not as much as with annual cover crops.There are some caveats in the study. This research was conducted in a loamy sand soil in Salinas Valley. Organic farmers in different regions may have different results. Using different types of fertilizers could impact results, as well."The growing body of information from this long-term trial challenges the overly-simplistic notion that certified organic management improves soil health or quality," says Brennan. He adds that the USDA organic standards require that certified farms show that their tillage and cultivation practices maintain or improve soil conditions. This refers to physical, chemical and biological factors. It also refers to minimizing soil erosion, which can worsen with intensive tilling.The team hopes that future research will focus on different soil types, such a clay or loam soil. Evaluating changes over shorter increments would provide useful data, too. The soil enzyme data tells one part of the interesting story of this relatively long-term experiment.
|
Agriculture & Food
| 2,019 |
August 7, 2019
|
https://www.sciencedaily.com/releases/2019/08/190807092326.htm
|
Eating more plant-based foods may be linked to better heart health
|
Eating mostly plant-based foods and fewer animal-based foods may be linked to better heart health and a lower risk of dying from a heart attack, stroke or other cardiovascular disease according to new research published in the
|
"While you don't have to give up foods derived from animals completely, our study does suggest that eating a larger proportion of plant-based foods and a smaller proportion of animal-based foods may help reduce your risk of having a heart attack, stroke or other type of cardiovascular disease," said lead researcher, Casey M. Rebholz, Ph.D., assistant professor of epidemiology at Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.Researchers reviewed a database of food intake information from more than 10,000 middle-aged U.S. adults who were monitored from 1987 through 2016 and did not have cardiovascular disease at the start of the study. They then categorized the participants' eating patterns by the proportion of plant-based foods they ate versus animal-based foods.People who ate the most plant-based foods overall had a:"Our findings underscore the importance of focusing on your diet. There might be some variability in terms of individual foods, but to reduce cardiovascular disease risk people should eat more vegetables, nuts, whole grains, fruits, legumes and fewer animal-based foods. These findings are pretty consistent with previous findings about other dietary patterns, including the Dietary Approaches to Stop Hypertension, or DASH diet, which emphasize the same food items," Rebholz said.This is one of the first studies to examine the proportion of plant-based versus animal-based dietary patterns in the general population, noted Rebholz. Prior studies have shown heart-health benefits from plant-based diets but only in specific populations of people, such as vegetarians or Seventh Day Adventists who eat a mostly vegan diet. Future research on plant-based diets should examine whether the quality of plant foods -- healthy versus less healthy -- impacts cardiovascular disease and death risks, according to the study, said Rebholz."The American Heart Association recommends eating a mostly plant-based diet, provided the foods you choose are rich in nutrition and low in added sugars, sodium (salt), cholesterol and artery-clogging saturated and trans fats. For example, French fries or cauliflower pizza with cheese are plant based but are low in nutritional value and are loaded with sodium (salt). Unprocessed foods, like fresh fruit, vegetables and grains are good choices," said Mariell Jessup, M.D., the chief science and medical officer of the American Heart Association.The study was observational, which means did not prove cause and effect.
|
Agriculture & Food
| 2,019 |
August 6, 2019
|
https://www.sciencedaily.com/releases/2019/08/190806151554.htm
|
Knowing berry pests' varied diets may help control them
|
With New York state's $20 million berry industry entering peak season, an invasive fruit fly is thriving.
|
But little has been known about how the pests survive before and after the growing season.A Cornell University study, published in Female spotted-wing "They will lay eggs and successfully develop on less preferred resources and not the typical fruit that we think they prefer," said Greg Loeb, professor of entomology at Cornell AgriTech and a co-author of the paper. Dara Stockton, a postdoctoral associate in Loeb's lab, is the paper's first author.In lab experiments, the researchers found that out of 11 alternate dietary choices that included bird manure, the spotted-wing In the early spring, mushrooms are one of the only resources available. Similarly, in late fall, apples that fall to the ground and rot can provide a food source. And the experiments showed that more complex bird manures, such as from geese, proved more sustaining than simple chicken manure, for example.The results may help curb pest populations by encouraging growers to limit access to certain non-fruit food sources during times when "It's always important for us, when we're developing integrated pest management control strategies, to think about the landscape surrounding the crop and consider things happening in the periphery that we can control," Stockton said. For example, controlling geese in a pond next to a crop could help limit fruit fly populations at a time when their numbers are low before berries ripen, she said."The more we learn about the flies, the better we can control their populations," Stockton said.Other experiments revealed that if an individual was reared on a certain food, such as goose manure, that fly is more likely to accept it later in its life than a fly that had never encountered it.Another experiment looked at survival over eight weeks when flies were limited to a single diet."We found that complex diets, including mushroom and apple, were superior to simpler diets in terms of survival long term," Stockton said. Along with varying diets, tests included lowering temperatures to simulate spring and fall and understanding nutritional components.Based on numbers of flies captured in traps, spotted-wing Rachael Brown, a former undergraduate intern in Loeb's lab from Hobart and William Smith Colleges in Geneva, New York, is a co-author of the study, which was funded by the U.S. Department of Agriculture.Cornell University has dedicated television and audio studios available for media interviews supporting full HD, ISDN and web-based platforms.
|
Agriculture & Food
| 2,019 |
August 6, 2019
|
https://www.sciencedaily.com/releases/2019/08/190806151551.htm
|
Tariffs lead to creative supply chains
|
Where there's a will to peddle soybeans in the global marketplace, there's a way, even if a trade war creates roadblocks.
|
In the recent issue of the international open-access journal In 2017, China imported 95.5 million metric tons of soybeans, worth nearly $40 billion -- 67% of the world's soybean supply. That trade comes with cascading economic and environmental consequences as countries change the way they use their land and natural resources to meet the demand.Anna Herzberger, a PhD candidate and fourth-generation farmer from central Illinois, and her colleagues applied the integrated framework of metacoupling to understand the true extent of global soybean trade. The framework, which examines socioeconomic and environmental interactions within as well as between distant and adjacent places, allow researchers to consider input from a variety of disciplines, and then model interactions and reactions that can be compared to reality.In addition to being part of a farming family, Herzberger has studied soybean farming practices in China's primary agricultural region in the northeastern Heilongjiang Province. She comments on those two worlds in FromTheFarm . org, which includes a recent post putting today's farmer concerns over soybean trade in both a historical and pro boxing context."In a time when international trade is being targeted by increased tariffs, it's even more important to understand the true impact of these tariffs across the world," said Jianguo "Jack" Liu, Rachel Carson Chair in The results, reported in "Telecoupled Food Trade Affects Pericoupled Trade and Intracoupled Production," show that the perception that Chinese swelling demand for foreign soybeans plays out only in Brazil is a limited view. Brazil has displaced the United States as China's top soybean importer. With that distinction comes more conversion of forestland to cropland or shifts from planting other crops in favor of soybeans.But the MSU team shows the changes don't end there. A closer look at the policies and planting decisions of neighbors show that some soybeans exported from Brazil were not grown in Brazil. Neighboring South American countries like Paraguay and Argentina restrict trading with China, yet their soybeans flow into Brazil as Brazil is shipping record amounts of soybeans to China."We're masking the true extent of China's demands when we only consider Brazil," Herzberger said. "We need to consider that what Brazil export in fact in part comes from other countries, which in turn points us to greater impacts that extend to Brazil's neighbors, even though some of those neighbors put in policies to avoid their markets being driven by China's market."
|
Agriculture & Food
| 2,019 |
August 6, 2019
|
https://www.sciencedaily.com/releases/2019/08/190806142335.htm
|
A hog in wolf's clothing
|
Human and wildlife conflict has increased along with expanding human populations, particularly when wildlife endanger humans or their livelihoods. Most research on human-wildlife conflict has focused on the ways tigers, wolves, and other predators impact livestock even though noncarnivores also threaten livestock. New research by Dr. Shari Rodriguez and Dr. Christie Sampson, both from Clemson University, publishing on August 6 in the open-access journal
|
"Our study highlights the importance of including species not traditionally considered in the livestock protection conversation, and finding similarities in how the effects of non-Carnivora species can be addressed through the same methodologies as species such as wolves, tigers, or lions," says Dr. Rodriguez.Results show that these species can have significant effects on livelihood by killing young and small livestock and damaging livestock farming infrastructure. They may also affect local communities' perception of the species, which in the case of species of conservation concern such as elephants could potentially reduce people's willingness to support conservation initiatives."Sharing experiences across taxa and adopting methodology found to be successful for other [predatory] species may help us to improve the tools we use to promote co-existence and conservation efforts for elephants," reported Dr. Sampson.
|
Agriculture & Food
| 2,019 |
August 6, 2019
|
https://www.sciencedaily.com/releases/2019/08/190806131446.htm
|
Guacamole lovers, rejoice! The avocado genome has been sequenced
|
Scientists have sequenced the avocado genome, shedding light on the ancient origins of this buttery fruit and laying the groundwork for future improvements to farming.
|
With regard to modern affairs, the study reveals for the first time that the popular Hass avocado inherited about 61 percent of its DNA from Mexican varieties and about 39 percent from Guatemalan ones. (Avocados come in many types, but Hass -- first planted in the 1920s -- comprises the bulk of avocados grown around the world.)The research also provides vital reference material for learning about the function of individual avocado genes, and for using genetic engineering to boost productivity of avocado trees, improve disease resistance and create fruit with new tastes and textures.The study is important for agriculture. The growing global market for avocados was worth about $13 billion in 2017, with Mexico, the largest producer, exporting some $2.5 billion worth of the fruit that year, according to Statista, a provider of market and consumer data. Around the world, avocados are spread on tortillas, mashed up to flavor toast, rolled into sushi and blended into milkshakes (a popular treat in parts of Southeast Asia).Scientists sequenced not only the Hass avocado, but also avocados from Mexico, Guatemala and the West Indies, which are each home to genetically distinct, native cultivars of the fruit.The project was led by the National Laboratory of Genomics for Biodiversity (LANGEBIO) in Mexico, Texas Tech University, and the University at Buffalo. The research was published on Aug. 6 in the "Avocado is a crop of enormous importance globally, but particularly to Mexico. Although most people will have only tasted Hass or a couple of other types, there are a huge number of great avocado varieties in the species' Mexican center of diversity, but few people will have tried them unless they travel south of the U.S. border. These varieties are genetic resources for avocado's future. We needed to sequence the avocado genome to make the species accessible to modern genomic-assisted breeding efforts," says Luis Herrera-Estrella, PhD, President's Distinguished Professor of Plant Genomics at Texas Tech University, who conceived of the study and completed much of the work at LANGEBIO, where he is Emeritus Professor, prior to joining Texas Tech University."Our study sets the stage for understanding disease resistance for all avocados," says Victor Albert, PhD, Empire Innovation Professor of Biological Sciences in the UB College of Arts and Sciences and a Visiting Professor at Nanyang Technological University, Singapore (NTU Singapore). Albert was another leader of the study with Herrera-Estrella. "If you have an interesting tree that looks like it's good at resisting fungus, you can go in and look for genes that are particularly active in this avocado. If you can identify the genes that control resistance, and if you know where they are in the genome, you can try to change their regulation. There's major interest in developing disease-resistant rootstock on which elite cultivars are grafted."While the avocado rose to international popularity only in the 20th century, it has a storied history as a source of sustenance in Central America and South America, where it has long been a feature of local cuisines. Hundreds of years ago, for example, Aztecs mashed up avocados to make a sauce called ?huacamolli.Before that, in prehistoric times, avocados, with their megapits, may have been eaten by megafauna like giant sloths. (It's thought that these animals could have helped to disperse avocados by pooping out the seeds in distant locations, Albert says.)The new study peers even further back into time. It uses genomics to investigate the family history of the avocado, known to scientists as Persea americana. "We study the genomic past of avocado to design the future of this strategic crop for Mexico," Herrera-Estrella said. "The long life cycle of avocado makes breeding programs difficult, so genomic tools will make it possible to create faster and more effective breeding programs for the improvement of this increasingly popular fruit."The avocado belongs to a relatively small group of plants called magnoliids, which diverged from other flowering plant species about 150 million years ago. The new research supports -- but does not prove -- the hypothesis that magnoliids, as a group, predate the two dominant lineages of flowering plants alive today, the eudicots and monocots. (If this is right, it would not mean that avocados themselves are older than eudicots and monocots, but that avocados belong to a hereditary line that split off from other flowering plants before the eudicots and monocots did.)"One of the things that we did in the paper was try to solve the issue of what is the relationship of avocados to other major flowering plants? And this turned out to be a tough question," Albert says. "Because magnoliids diverged from other major flowering plant groups so rapidly and so early on, at a time when other major groups were also diverging, the whole thing is totally damn mysterious. We made contributions toward finding an answer by comparing the avocado genome to the genomes of other plant species, but we did not arrive at a firm conclusion."Magnoliids were estimated by a 2016 research paper to encompass about 11,000 known living species on Earth, including avocados, magnolias and cinnamon. In comparison, some 285,000 known species were counted as eudicots and monocots.Scientists don't know how old the avocado is, and the new study doesn't address this question. But the research does explore how the avocado has changed -- genetically -- since it became its own species, branching off from other magnoliids.The paper shows that the avocado experienced two ancient "polyploidy" events, in which the organism's entire genome got copied. Many of the duplicated genes were eventually deleted. But some went on to develop new and useful functions, and these genes are still found in the avocado today. Among them, genes involved in regulating DNA transcription, a process critical to regulating other genes, are overrepresented.The research also finds that avocados have leveraged a second class of copied genes -- tandem duplicates -- for purposes that may include manufacturing chemicals to ward off fungal attacks. (Tandem duplicates are the product of isolated events in which an individual gene gets replicated by mistake during reproduction.)"In the avocado, we see a common story: Two methods of gene duplication resulting in very different functional results over deep time," Albert says."In plants, genes retained from polyploidy events often have to do with big regulatory things. And genes kept from the more limited one-off duplication events often have to do with biosynthetic pathways where you're making these chemicals -- flavors, chemicals that attract insects, chemicals that fight off fungi. Plants are excellent chemists," Herrera-Estrella says.Having addressed some ancient mysteries of the avocado, the new study also moves forward in time to explore a modern chapter in the story of this beloved fruit: how humans have altered the species' DNA.Because commercial growers typically cultivate avocados by grafting branches of existing trees onto new rootstocks, today's Hass avocados are genetically the same as the first Hass avocado planted in the 1920s. These modern-day Hass avocados are grown on Hass branches grafted onto various rootstock that are well adapted for particular geographic regions.While the Hass avocado was long thought to be a hybrid, the details of its provenance -- 61 percent Mexican, 39 percent Guatemalan -- were not previously known. The scientists' new map of the Hass avocado genome reveals huge chunks of contiguous DNA from each parental type, reflecting the cultivar's recent origin."Immediately after hybridization, you get these giant blocks of DNA from the parent plants," Herrera-Estrella says. "These blocks break up over many generations as you have more reproductive events that scramble the chromosomes. But we don't see this scrambling in the Hass avocado. On chromosome 4, one whole arm appears to be Guatemalan, while the other is Mexican. We see big chunks of DNA in the Hass avocado that reflect its heritage.""We hope that the Mexican Government keeps supporting these types of ambitious projects that use state-of-the-art technology to provide a deep understanding of the genetics and genomics of native Mexican plants," Herrera-Estrella said.The research was funded by SAGARPA/CONACYT, the Governors University Research Initiative of the State of Texas, the U.S. National Science Foundation, Horticulture Innovation Australia Ltd. and the Australian Bureau of Agricultural and Resource Economics and Sciences.
|
Agriculture & Food
| 2,019 |
August 5, 2019
|
https://www.sciencedaily.com/releases/2019/08/190805195328.htm
|
Road verges provide refuge for pollinators
|
Roadside verges provide a vital refuge for pollinators -- but they must be managed better, new research shows.
|
With many pollinator species in decline, the University of Exeter study shows verges can provide food and a home for pollinators such as bees, butterflies and hoverflies.But the study emphasises that not all verges are equal. It found pollinators prefer less busy roads and areas deeper into verges.It also found that cutting verges in summer, which removes wildflowers, makes them useless for pollinators for weeks or even months."Road verges can provide a fantastic home for wildflowers and pollinators, which is often lacking in our vast agricultural landscapes," said lead author Ben Phillips, of the Environment and Sustainability Institute on Exeter's Penryn Campus in Cornwall."But management is key -- some road verges need to be cut for safety, but at the moment we cut far more than we need to."Most verges are cut in summer -- the peak of flowering -- but where possible they should be left until autumn, when pollinators are less active."Our results show that the part of the verge within two metres of the road contains the fewest pollinators."This is often the most important part to cut for road safety and visibility, so where possible only this part should be cut in summer."A campaign by conservation charity Plantlife to save wildlife on road verges includes a petition signed by more than 70,000 people.Plantlife's key message, strongly supported by the new study, is to "cut less, cut later."With 97% of wildflower meadows lost since the 1930s, the new study emphasises the vital role that road verges could play in conserving pollinators and other wildlife.The study, carried out in collaboration with the NERC Centre for Ecology and Hydrology, was funded by the Natural Environment Research Council and the Cornwall Area of Outstanding Natural Beauty unit.
|
Agriculture & Food
| 2,019 |
August 5, 2019
|
https://www.sciencedaily.com/releases/2019/08/190805162829.htm
|
Missing link in algal photosynthesis found, offers opportunity to improve crop yields
|
Photosynthesis is the natural process plants and algae utilize to capture sunlight and fix carbon dioxide into energy-rich sugars that fuel growth, development, and in the case of crops, yield. Algae evolved specialized carbon dioxide concentrating mechanisms (CCM) to photosynthesize much more efficiently than plants. This week, in the journal
|
"Most crops are plagued by photorespiration, which occurs when Rubisco -- the enzyme that drives photosynthesis -- cannot differentiate between life-sustaining carbon dioxide and oxygen molecules that waste large amounts of the plant's energy," said James Moroney, the Streva Alumni Professor at LSU and member of Realizing Increased Photosynthetic Efficiency (RIPE). "Ultimately, our goal is to engineer a CCM in crops to surround Rubisco with more carbon dioxide, making it more efficient and less likely to grab oxygen molecules -- a problem that is shown to worsen as temperatures rise."Led by the University of Illinois, RIPE is an international research project that is engineering crops to be more productive by improving photosynthesis with support from 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).Whereas carbon dioxide diffuses across cell membranes relatively easily, bicarbonate (HCO3-) diffuses about 50,000 times more slowly due to its negative charge. The green algae "Before now, we did not understand how bicarbonate crossed the third threshold to enter the pyrenoid," said Ananya Mukherjee, who led this work as a graduate student at LSU before joining the University of Nebraska-Lincoln as a postdoctoral researcher. "For years, we tried to find the missing component, but it turns out there are three transport proteins involved in this step -- which were the missing link in our understanding of the CCM of "While other transport proteins are known, we speculate that these could be shared with crops more easily because Chlamy is more closely related to plants than other photosynthetic algae, such as cyanobacteria or diatoms," said Luke Mackinder, a lecturer at York who collaborated with the RIPE team on this work with support from the Biotechnology and Biological Sciences Research Council (BBSRC) and the Leverhulme Trust.Creating a functional CCM in crops will require three things: a compartment to store Rubisco, transporters to bring bicarbonate to the compartment, and carbonic anhydrase to turn bicarbonate into carbon dioxide.In a 2018 study, RIPE colleagues at The Australian National University demonstrated that they could add a compartment called a carboxysome, which is similar to a pyrenoid, in crops. Now this study completes the list of possible transport proteins that could shuttle bicarbonate from outside the cell to this carboxysome structure in crops' leaf cells."Our research suggests that creating a functional CCM in crops could help crops conserve more water and could significantly reduce the energy-taxing process of photorespiration in crops -- that worsens as temperatures rise," Moroney said. "The development of climate-resilient crops that can photosynthesize more efficiently will be vital to protecting our food security."Realizing Increased Photosynthetic Efficiency (RIPE) is engineering staple food crops to more efficiently turn the sun's energy into food to sustainably increase worldwide food production, with support from the Bill & Melinda Gates Foundation, the U.S. Foundation for Food and Agriculture Research, and the U.K. Government's Department for International Development.
|
Agriculture & Food
| 2,019 |
August 5, 2019
|
https://www.sciencedaily.com/releases/2019/08/190805134039.htm
|
Pesticides deliver a one-two punch to honey bees
|
A new article reveals that adjuvants, chemicals commonly added to pesticides, amplify toxicity affecting mortality rates, flight intensity, colony intensity, and pupae development in honey bees.
|
Adjuvants are chemicals that are commonly added to plant protection products, such as pesticides, to help them spread, adhere to targets, disperse appropriately, or prevent drift, among other things. There was a widespread assumption that these additives would not cause a biological reaction after exposure, but a number of recent studies show that adjuvants can be toxic to ecosystems, and specific to this study, honey bees. Jinzhen Zhang and colleagues studied the effects on honey bees when adjuvants were co-applied at "normal concentration levels" with neonicotinoids. Their research, recently published in When applied alone, the three pesticide adjuvants caused no significant, immediate toxicity to honeybees. However, when the pesticide acetamiprid was mixed with adjuvants and applied to honeybees in the laboratory, the toxicity was quite significant and immediate. In groups treated with combined pesticide-adjuvant concentrates, the mortality was significantly higher than the control groups, which included a blank control (no pesticide, no adjuvant, only water) and a control with only pesticide (no adjuvant). Further, flight intensity, colony intensity and pupae development continued to deteriorate long after the application comparative to the control groups.Zhang noted that this study, "contributed to the understanding of the complex relationships between the composition of pesticide formulations and bee harm," and stressed that "further research is required on the environmental safety assessment of adjuvants and their interactions with active ingredients on non-target species."
|
Agriculture & Food
| 2,019 |
August 5, 2019
|
https://www.sciencedaily.com/releases/2019/08/190805134019.htm
|
Insects as livestock: Considering nutritional needs of insects
|
Given that they generate hardly any greenhouse gases, are undemanding, nutritious and fast growing, insects have generated a lot of hype in recent years. They are touted as the superfood of the future -- cheap suppliers of protein that can even decompose all kinds of residual products.
|
"This all sounds very promising, but has little to do with reality," says Wilhelm Windisch, Professor of Animal Nutrition at the Technical University of Munich. "Anyone who hopes to keep animals professionally and on a large scale needs to know exactly what kinds of nutrients they need and can consume. And for insects, this is yet to be determined."In collaboration with a German-Kenyan research team, the agricultural scientist has for the first time ever systematically investigated how various feed substrates influence the growth and development of crickets (In the wild, both species feed on leaves. "But supplying large insect farms with fresh greens year-round is virtually impossible to implement," says Windisch. "You need feed of verifiable quality and safety that can be dried, stored and transported."Commercial animal feed would fulfill these criteria. But, does it meet the nutritional needs of insects? At the Centre of Insect Physiology and Ecology (ICIPE) in Nairobi, the team investigated how the two species responded to different feed choices.They tested different dry feed variants containing cornstarch, protein and fiber-rich cowpea leaves, protein-rich soy extract and vitamin-enriched carrot powder.The researchers logged the amount of feed provided every day, weighed the excrements and finally determined the average weight of the adult insects. Two rounds of tests were carried out and evaluated over a three-month period."The result surprised us," recalls Windisch: "It was clear to us that the metabolism and digestion are rather different in insects than in conventional farm animals such as cattle, pigs and chickens. What we did not expect were immense species-specific differences."Locusts, for example, can process plant fibers that are indigestible by humans. Crickets, on the other hand, excrete fiber-rich food. Locusts grow quickly only when fed protein, while crickets need starch, above all.The source of the differences is still unclear. In their next project, the researchers hope to investigate which enzymes are active in the intestines of various insects and which of them can, for example, convert plant fiber into glucose."The research is still in its infancy, but with each result we understand the metabolism and nutrient needs of individual genera better and can use the outcomes in professional insect farms to process biomass that, for example, could not be used previously because it is inedible for humans and livestock can process it poorly, at best," sums up Windisch.
|
Agriculture & Food
| 2,019 |
August 5, 2019
|
https://www.sciencedaily.com/releases/2019/08/190805134015.htm
|
Scientists propose environmentally friendly control practices for harmful tomato disease
|
Tomato yellow leaf curl disease (TYLCD) caused by tomato yellow leaf curl virus-like viruses is the most destructive disease of tomato, causing severe damage to crops worldwide and resulting in high economic losses. To combat this disease, many farmers opt for intensive application of insecticides. However, this practice is frequently ineffective and has a negative impact on the environment and human health.
|
Alternatively, some farmers plant TYLCD-resistant tomato varieties, but these hybrid varieties are often tasteless and a poor comparison to the robust flavor of traditional tomatoes. As a result, there is a demand for effective and environmentally friendly control measures to prevent continuing widespread damage of TYLCD, as well as other plant viruses.To answer this demand, a team of scientists at the Spanish Council of Scientific Research (IHSM UMA-CSIC) conducted field and greenhouse trials for three consecutive years and found two environmentally friendly control alternatives to insecticides.First, they discovered that protecting tomato crops with UV-blocking plastics led to reduced TYLCD damage. Secondly, they found that the application of a salicylic acid analogue to strengthen tomato plant defenses was also effective in reducing TYLCD-associated losses.For the most effective results, the team recommends that farmers combine both control practices. These practices are proposed for commercial use in open field or on protected tomato crops. These findings also suggest the possibility for future discovery of environmentally friendly virus control strategies.
|
Agriculture & Food
| 2,019 |
August 2, 2019
|
https://www.sciencedaily.com/releases/2019/08/190802123536.htm
|
Greening devastates the citrus industry: New research offers a solution
|
Citrus Huanglongbing (HLB), also known as greening, is one of the most serious citrus plant diseases in the world. Infected trees produce bitter fruits that are green, misshapen, and unsuitable for sale. Once a tree is infected, there is no cure and it typically dies within a few years. Greening has already devastated the Florida citrus industry and poses a threat to California and Texas as well as Australia and the Mediterranean region.
|
Currently the most effective ways to prevent the spread of HLB are to stop the causal agent (Professor Nian Wang and his postdoctoral research associate Dr. Sheo Shanker Pandey, both from Citrus Research and Education Center, Department of Microbiology and Cell Science, at the Institute of Food and Agricultural Sciences of University of Florida, developed a strategy for early diagnosis of HLB before the appearance of blotchy mottle symptoms. They used a low-cost staining method to identify insect feeding sites and tested those identified sites for the causal agent using quantitative real-time PCR (polymerase chain reaction).Through this method, the pair were able to detect the HLB causal agent up to two days after transmission and long before the appearance of symptoms. This early detection will enable citrus growers to prevent the spread of HLB in their fields. This finding is especially crucial for California, Texas, Australia, and the Mediterranean region as those areas are currently plagued by HLB.
|
Agriculture & Food
| 2,019 |
August 2, 2019
|
https://www.sciencedaily.com/releases/2019/08/190802104537.htm
|
Finding new knowledge in history: Evaluating seven decades of ex situ seed regeneration
|
The Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) in Gatersleben has been promoting the transition of gene banks into bio-digital resource centres - the aim is the preparation and collation of the phenotypic and genetic information for all stored accessions. As an important step for the further development of the Federal Ex situ Gene Bank, which is being hosted by the IPK in Gatersleben, researchers have been evaluating the historical data which has been accrued by the gene bank over the last 70 years. Not only is the resulting published data an important new resource for researchers and plant breeders, the publications also provide blueprint strategies for the preparation of correlated datasets from which other gene banks and research facilities will be able to draw.
|
Gene banks have long outgrown their role as mere "storage facilities" of different plant accessions. With the increasing need for new and improved crop species due to climate change and the continuously growing world population, their importance as providers of novel phenotypic and genetic resources for plant breeders and researchers is becoming clearer. The steady progression of omics-technologies and the efforts of researchers worldwide have already started driving the evolution of the gene banks into the envisioned all-encompassing bio-digital resource centres. A group of scientists from the IPK in Gatersleben has been supporting the evolution of the Federal Ex situ Gene Bank by analysing the historical phenotypic data of different crops which was compiled over the last seven decades and making the data available to the public in a highly structured manner.Analysing large amounts of phenotypic data is no small feat, considering that the gene bank hosted by the IPK with its collection of roughly 151,000 accessions counts as one of the ten largest gene banks worldwide. In addition, about 5% of the collection need to be regrown annually to regenerate the seeds. Due to this, further questions arise such as how to deal with non-orthogonal experimental designs, changes in agronomic practices or in weather patterns? And how to assess the quality of data which has been collected over such long periods of time and with different methods? Over a series of papers, the IPK researchers led by Prof. Dr. Jochen Reif have been examining and finding solutions to these challenges.Focusing on the agronomic traits flowering time, plant height, and thousand grain weight, the scientists developed statistical models with which they were able to leverage maximal information from the available datasets. Employing innovative approaches for data analysis (for further reading see their 2018 Frontiers publication), they established an outlier corrected dataset as well as ready-to-use processed phenotypic data in the form of 'Best Linear Unbiased Estimations' (BLUEs). The BLUEs data now complement the passport information of a large number of accessions stored at the Gene Bank and allows the direct comparison of accessions across the different regeneration years.The scientists had previously processed the historical data of the majority of the barley accessions stored at the Ex situ Gene Bank. A new paper, published in Even though the historical data behind barley and wheat is now being prepared for further use by plant researchers and breeders, there is still plenty of phenotypic data for different accessions but also for different crops left - as well at the Federal Ex situ Gene Bank but also at the other gene banks worldwide. The data publications by the IPK researchers showcase methodologies which can be adapted for such further data evaluation-projects.And whilst their results may stimulate new avenues for barley and wheat research and breeding, they also show how much potential and knowledge can be hidden away in seemingly dusty records - once the correct methods to unlock the hidden data have been found.
|
Agriculture & Food
| 2,019 |
August 2, 2019
|
https://www.sciencedaily.com/releases/2019/08/190802104532.htm
|
Bittersweet truth of how bee-friendly limonoids are made
|
Limonoids are a class of plant natural products whose complex chemistry has been intensively investigated for over 50 years.
|
The best known limonoid, azadirachtin, is famous for being bee-friendly yet having a strong anti-insect effect; others are well known for contributing bitterness to citrus fruits, while further examples such as nimbolide, are being investigated for potential pharmaceutical anti-cancer uses.Yet, despite this wealth of research, how plants even begin to make these useful chemicals has remained a mystery -- until now.Researchers from the John Innes Centre and Stanford University have uncovered new genes that encode this high-value chemistry.The team used genome mining resources to identify three new enzymes which can make the limonoid precursor melianol and therefore represent the initial steps of limonoid biosynthesis.Due to the complex chemical structure of limonoids, it is difficult to chemically synthesise these natural products. As a result, their use is currently limited to what can be extracted from plant materials.Understanding how melianol is made opens the door to metabolic engineering of limonoids in which the newly discovered genes can be expressed in plants or microbial hosts. It is a step towards large-scale production of limonoid pharmaceuticals and possible development of insect-resistant crops."If this engineering could be achieved, then crops could be developed with an inherent resistance to insects, which could reduce reliance on chemical application for crop protection. Additionally, larger amounts of useful limonoids could be made available to pharmaceutical industries, which could accelerate research into potential medicinal uses of limonoids," explains lead author Hannah Hodgson."Our next step is to find and characterise the remaining enzymes required to convert melianol to limonoids. This will be a challenge, but we believe that identifying the enzymes required to produce melianol represents a strong starting point," she adds.Limonoids are made by plants belonging to the Mahogany (Here the John Innes Centre team characterised enzymes from
|
Agriculture & Food
| 2,019 |
August 1, 2019
|
https://www.sciencedaily.com/releases/2019/08/190801152701.htm
|
Three concepts from complexity could play a big role in social animal research
|
From bees to birds to humans, the animal kingdom is full of organisms that have evolved complex social structures to solve specific problems they encounter. Explaining why some species evolved more complex societies than others has been a fundamental challenge in the field of social animal research, and might be best approached with tools from complex systems, according to a team of researchers from the Santa Fe Institute.
|
Some complexity science concepts are already part of the lexicon of biology. For instance, evolution and adaptation are foundational to both fields. In a recent paper in "None of these three concepts are, by themselves, diagnostic of a complex system, but all three are often part of one," says Elizabeth Hobson (University of Cincinnati), a former SFI complexity postdoc and lead author on the paper. "These concepts could lead us in totally new directions and offer new insights into animal social complexity."The four authors on the paper come from wildly different perspectives, says mathematician Joshua Garland (Santa Fe Institute). Garland and Hobson, together with SFI Postdoctoral Fellow Artemy Kolchinsky and former SFI Omidyar Fellow Vanessa Ferdinand (University of Melbourne), span fields including information theory and neurology, cultural evolution, mathematics, and animal behavior. "The range of fields made it challenging to agree on just three concepts, but the diversity of perspectives is an asset to this paper," says Garland.The first concept -- social scales -- is important to consider when measuring complexity in animal societies, because the level of complexity may vary across scales. The interactions of two individual honeybees, for example, may be quite simple, while the organizational structure of the hive can be highly complex.The second concept, compression describes how systems encode information. Animal researchers could use compression to better compare different animal systems to one another or to describe the possible cognitive processes that allow social animals to remember relationships and group structures. "It could help us understand how animals reduce the overall cognitive load while functioning in their societies," says Hobson.The final concept, emergence, is when a new pattern appears, often at a higher level of social organization, from lower-level interactions. A classic example is the wave-like behavior of a large flock of birds -- something that can't exist at the individual level. Other social behaviors, like dominance hierarchies, culturally learned behaviors, or leadership within groups can also exhibit emergent properties.Hobson and her co-authors suggest researchers consider these tools when exploring animal social complexity measures. "Taken together, we hope these three concepts from complex systems can help us better tackle longstanding questions about animal social structure and help better compare sociality across species," says Hobson."These are three big concepts that are both important and immediately applicable," says Garland. "but they just scratch the surface of complex systems ideas that could be useful for animal sociality research."
|
Agriculture & Food
| 2,019 |
August 1, 2019
|
https://www.sciencedaily.com/releases/2019/08/190801142559.htm
|
New signaling component important for plant symbiosis
|
A proteomics-based protein-protein interaction study has led to the discovery of proteins that interact with a legume receptor that mediates signal transduction from the plasma membrane to the nucleus. This shows how symbiotic signals from symbiotic bacteria are transmitted upon perception, ultimately leading to their accommodation within the host plant.
|
Legumes are of significant agricultural importance mainly due to their abilities to establish symbiotic relationship with nitrogen-fixing bacteria known as rhizobia. A deeper understanding of biological nitrogen fixation (BNF) and subsequent transfer of this knowledge to crop plants would allow us to circumvent the use of fertilizers and grow crops sustainably. In addition, the successful transfer of BNF to non-legume crops would especially benefit smallholder farmers who can then increase crop yield without facing cash constraints associated with the purchase of inorganic fertilizers.To contribute to this goal, members of the Plant Molecular Biology group at Aarhus University directed by Professor Jens Stougaard have dedicated their research to understanding legume-rhizobial symbiosis. In 2003, the group identified the plasma-membrane localized Nodulation (Nod) factor receptors 1 and 5 (NFR1 and NFR5) responsible for the recognition of compatible symbionts; Nod factors are symbiotic signalling molecules that vary in structure depending on the rhizobium species. Using a stringent lock (Nod factor receptors) and key (Nod factor) mechanism, only compatible rhizobia are allowed to enter the plant while incompatible bacteria will not be able to infect and colonize the root nodules.For over 15 years, components involved in directly relaying Nod factor signals downstream of Nod factor receptors have remained elusive, limiting the researchers' understanding of how these Nod factor receptors ultimately lead to changes in root hair structure and formation of new organs (nodules) required for rhizobia entry and accommodation. A breakthrough was finally achieved using an elegant Proteomics approach and by taping on the expertise of colleagues from Cyril Zipfel's research group (The Sainsbury Laboratory, UK) who have constantly unravelled new players in plant defence signalling.The work published in the The Nod factor and Nod factor receptor triggered movement of NiCK4 from the plasma membrane to the nucleus is very exciting data as calcium oscillations in the nucleus is a hallmark of symbiosis signalling in legumes. Following this discovery, the research team hopes to assemble and connect more symbiosis signalling components. A thorough understanding of all components involved in the symbiosis signalling pathway is crucial for successful transfer of BNF to non-legume crops.
|
Agriculture & Food
| 2,019 |
August 1, 2019
|
https://www.sciencedaily.com/releases/2019/08/190801142546.htm
|
EU agriculture not viable for the future
|
The current reform proposals of the EU Commission on the Common Agricultural Policy (CAP) are unlikely to improve environmental protection, say researchers led by the German Centre for Integrative Biodiversity Research (iDiv), the Helmholtz Centre for Environmental Research (UFZ) and the University of Göttingen in the journal
|
Agricultural areas cover 174 million hectares, or 40 percent of the EU area (over 50 percent in Germany). Land use intensification, primarily by agriculture, is identified by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) as the number one cause of biodiversity loss, with risk to human wellbeing resulting from losses of biodiversity and ecosystem services.The European Union, and thus also Germany, has committed in various international agreements to shift toward sustainable agriculture, the protection of biodiversity, and combatting climate change. With approx. 40 percent of the total budget, the European Union's Common Agricultural Policy (CAP) is one of the most important policy areas for implementing these international commitments. "The proposal made by the European Commission for the CAP post-2020, published in June 2018, demonstrates very little of this intention," says a research team led by Dr Guy Pe'er (iDiv, UFZ) and Dr Sebastian Lakner (University of Göttingen).The researchers analysed the proposal for the CAP post-2020 with a focus on three questions: Is the reform proposal compatible with the UN's Sustainable Development Goals (SDGs), does it reflect public debate on agriculture, and, does it offer a clear improvement compared to the current CAP? The analysis was based on a comprehensive review of the literature with about 450 publications, addressing issues such as effectiveness, efficiency and relevance of the CAP. The scientists' conclusion: The proposed CAP represents a clear step backwards compared with the current one."Taking sustainability and the SDGs seriously requires a deep reflection on agricultural policy, its budgets and instruments, and developing good indicators for measuring success," says ecologist Guy Pe'er. "Beyond words, we found little of that." According to the researchers, the CAP has the potential to support at least nine of the seventeen SDGs, but currently it only contributes to achieving two of them.The researchers also criticize that the EU wants to maintain some of the CAP instruments that have been proven to be inefficient, harmful to the environment and socially unfair. One key example for an inefficient instrument are the Direct Payments under the so-called Pillar 1 of the CAP. Around 40 billion euros (about 70 percent of the CAP budget) are paid to farmers on the basis of the cultivated area alone. This leads to unequal funding distribution: 1.8 percent of recipients get 32 percent of the money."These compensatory payments, provisionally introduced in 1992 as an interim solution, are lacking a sound scientific justification," says agricultural economist Sebastian Lakner of the University of Göttingen. According to the researchers' analysis, Direct Payments contribute very little both to environmental or social goals.This criticism is not new, and was already reflected by the EU in 2010 with the so-called 'Greening' of Direct Payments -- but the Greening attempt was watered down by political pressure during the last reform process and ended up largely ineffective, say the researchers.The EU Commission proposes to maintain and even expand Direct Payments, but came up with a so-called new 'green architecture' in response to the widespread criticism. This includes an expansion of the Good Environmental Agricultural Criteria and new voluntary measures called 'eco-schemes' in Pillar 1. In addition, the EU commission states that 40 percent of the CAP shall be labelled as 'climate-friendly'. But according to the researchers, this calculus remains questionable. And while agricultural greenhouse gas emissions are currently rising rather than declining, the Commission offers no suitable specific instruments to address climate change.Pillar 2, called 'Rural Development Programme', offers much better tools to address biodiversity protection and climate change. While environmental instruments in Pillar 2 take merely one tenth of Pillar 1, the Commission suggests to considerably cut Pillar 2 by 28 percent in the coming years, risking both environment and rural societies, according to the researchers.The researchers believe the key reason for the environmental shortfalls lies in an unbalanced reform process which allows powerful lobby organisations far-reaching opportunities to influence the reform and promote own interests, excluding important players from science and society."The EU obviously lacks the will to meet public demand for sustainable agriculture and to implement the global environmental and development goals it had a share in adopting," says Pe'er. "Lobby interests have clearly outweighed both ample evidence and public interests." According to an EU survey, 92 percent of the citizens and 64 percent of farmers say that the CAP should improve its performance with respect to environmental and climate protection.The researchers see the termination of Direct Payments one key task for improving the CAP. In the short term, Pillar 2 should be strengthened, and measures that have been proven to be beneficial for biodiversity and sustainability should be supported in order to meet the SDGs.Pe'er and Lakner see the newly-elected European Parliament as an opportunity to reshape the reform process in order to still meet public will and the EU's commitments to international obligations: "There is sufficient scientific evidence on what works and what doesn't, especially with respect to the environment," says Pe'er. "It should be in the core interest of the EU Commission to use tax payers' money more efficiently to support societal objectives such as the maintenance of biodiversity or in general sustainable agriculture," adds Lakner. The scientists believe that a genuine reform process, which involves all relevant stakeholders and takes scientific findings seriously, can help rebuilding public support and acceptance of the CAP .The final round of CAP negotiations between the European Commission, the European Council and the European Parliament is expected to start in autumn.
|
Agriculture & Food
| 2,019 |
July 31, 2019
|
https://www.sciencedaily.com/releases/2019/07/190731153813.htm
|
Previously unknown mechanism causes increased forest water use
|
Researchers have discovered a previously unknown mechanism that causes increased forest water use, advances understanding of soil biogeochemical control of forest water cycles and highlights threats to plants from water stress under acid deposition, according to a new study.
|
In a study published in the journal Lixin Wang, an associate professor in the School of Science at IUPUI, is the senior author of this research, and his Ph.D. student Matthew Lanning is the first author.This research is funded by the National Science Foundation's Hydrological Sciences program. Other authors of the research team include Todd Scanlon and Howard Epstein at the University of Virginia, Matthew Vadeboncoeur at the University of New Hampshire, Mary Beth Adams at the United States Forest Service, and Daniel Druckenbrod at Rider University.Calcium plays a unique role in plant cells by regulating the minute pores, called stomata, in the plants' leaves or stems, Wang said. If plants don't have enough calcium, they can't close those pores, and their water use increases. Also, when plants suffer from calcium deficiency, they will pump up more water through transpiration, the process of water movement through a plant and its evaporation from leaves, to meet their calcium demand, he said."We hypothesized that the leaching of the soil calcium supply, induced by acid deposition, would increase large-scale vegetation water use," Lanning said. "We present evidence from a long-term whole watershed acidification experiment demonstrating that the alteration of the soil calcium supply by acid deposition can significantly intensify water use."The researchers found multiple lines of evidence showing that calcium leaching induced by acid deposition not only increased vegetation water use but markedly decreased the soil water pool on the treated watershed."When plants are always using a lot of water, it means there will be less water left for people," Wang said. "It also means that these plants are very sensitive to drought. If a drought comes, and they can't close their stomata, they are subject to high levels of mortality due to water stress."Traditionally, forest water use was considered a function of meteorological factors, species composition and soil water availability. The impacts of soil biogeochemistry on large-scale forest water use had not been investigated.Nitrate and sulfate deposition are the primary drivers of soil acidification in the northeastern United States and eastern Europe, where atmospheric inputs exceed soil-generated acidity. In the United States and most of Europe, emissions of nitrate and sulfate have been curbed by legislation, but the impacts of acid deposition are still of global concern, especially in areas downwind of major cities or high-production agricultural areas.
|
Agriculture & Food
| 2,019 |
July 31, 2019
|
https://www.sciencedaily.com/releases/2019/07/190731112959.htm
|
Poisonous grasses and livestock
|
Stories of mass poisoning incidents of livestock due to toxic grasses made headlines especially overseas. Animal ecologists have studied whether this hazard is also lurking on German pastures.
|
"Dangerous Pastures: Deadly Grass Puts Horses at Risk" -- Such dire warnings on the websites of horse owners and horse lovers may cause people to see their environment in a whole new light. Because what they once considered the epitome of pristine nature, green meadows of grass gently swaying in the wind, is actually home to numerous toxic substances that can be lethal for horses, cattle and sheep.Scientists from the Department of Animal Ecology and Tropical Biology of the University of Würzburg have teamed up with US researchers to find out whether this is also true for Germany. To accomplish this, PhD student Veronika Vikuk and Professor Jochen Krauß, her mentor, analysed the toxicity of 13 grass species in three German regions. Their results published in the journal Strictly speaking, it is not the grass itself that endangers the lives of horses and other grazing animals: "Grass species can form a symbiosis with fungal endophytes of the genus Epichloë. These fungi are capable of producing so-called alkaloids that can be poisonous to grazing livestock," Veronika Vikuk describes the problem. Endophytes are fungi that live within a plant and are usually not visible from the outside. Both partners benefit from the symbiotic relationship: The grass host provides nutrients for the endophyte and the endophyte helps protect the plant from drought stress and pests. When danger is imminent, the forage grass can encourage the fungus to step up toxin production to prevent animals from eating the plant."We have learned of this symbiosis mainly through poisoning incidents of grazing livestock such as sheep or cattle in New Zealand, Australia and North America," Jochen Krauß explains. Around 100,000 animals are believed to have died as a result of toxic grasses in Australia in 2002; the annual costs for the farmers are estimated at two billion dollars. But not everyone considers the fungus to be a threat. Turfgrass breeders welcome the symbiosis of certain turf varieties and special fungi because it increases stress tolerance and boosts yield. For this reason, some grass seeds are deliberately infected with special endophytes.In Europe, reports of such poisoning incidents of grazing livestock have been rare so far," Veronika Vikuk says and she adds that previously little had been known about the infection rates of different grass species in Germany and the type of toxins produced. The study published by an international team of researchers has changed that. For the first time, it provides a comprehensive overview of infection rates and alkaloid production in grasses infected with Epichloë fungi in Germany. The study found that five of the 13 grass species tested are infected with various Epichloë fungi. They produce substances that are poisonous to insects and vertebrates. The researchers are still figuring out how high the toxin concentrations are and whether they are already life-threatening for the animals.In its study, the international team of researchers determined the presence or absence of different genes required to produce the alkaloids. Subsequently, they analysed which toxins are actually produced in the laboratory to assess the potential toxicity. They believe that this method is well suited to evaluate the endophyte status on pastures and check it on a regular basis to avoid livestock poisoning in the future.In one aspect, however, Vikuk and Krauß give the all-clear: "We were able to show that the start gene for the production of ergovaline, a substance that is poisonous to vertebrates, is largely absent in perennial ryegrass in Germany and that the substance is actually not produced," Vikuk says. This piece of information should be of particular interest to seed developers seeking to harness the benefits of fungal infection while avoiding the negative impacts on grazing livestock. This does not apply to lolitrem B, another vertebrate poison found in perennial ryegrass, which is present in toxic concentrations.The scientists believe that the risk of poisoning for horses, cattle or sheep can be reduced with relatively little effort: "Farmers should increase the diversity on their pastures and avoid monocultures, especially of perennial ryegrass," Jochen Krauß says. Mass poisoning of livestock occurs mostly in areas where the animals are forced to feed on the toxic grass because there are no alternatives. On meadows which are home to a variety of different plant species, the animals can switch to other grasses and thereby avoid high toxin levels.More diversity is also recommended in view of global warming. After all, grasses that live in a symbiosis with fungal endophytes have an advantage over grass species not infected by the fungus as our climate becomes warmer and drier due to their higher stress tolerance. If no measures are taken, the scientists fear that the risk of poisoning for grazing animals will rise in Germany, too, as a result of climate change.
|
Agriculture & Food
| 2,019 |
July 31, 2019
|
https://www.sciencedaily.com/releases/2019/07/190731102228.htm
|
Overturning the truth on conservation tillage
|
Just as we blend, cut, and fold ingredients together to follow a recipe, farmers use equipment to stir together soil and crop residue (stalks and roots of previous crops) before planting. This mechanical action is called tillage.
|
Similar to our kitchen cupboard with a blender, mixer, and beater, farmers have access to a variety of tillage equipment. Farmers choose the "right" piece of tillage based on many factors, including location, soil type, crop, and landscape.Tillage has been around for thousands of years. "It is difficult for nearly anyone to grow a crop, or even a garden, without unconsciously going through the motions of tillage," says Aaron Daigh. "I see it as a near equivalent to muscle memory or a natural reflex." Daigh is a researcher and professor at North Dakota State University.Modern conservation tillage practices protect the soil and environment. For example, they can reduce erosion from water or wind and keep nutrients in the right place.Farmers are showing more and more interest in adapting conservation practices on their operations. But, adopting a new tillage system can be intimidating due to many real and perceived concerns. For example, some farmers presume conservation tillage will lead to lower yields and an increased risk for seedling diseases.Scientists are making it easier for farmers in the Midwest to make the right tillage decisions when considering modern conservation practices. Daigh and his team compared the effects of three common conservation tillage systems to the traditional method of a chisel plow with field cultivation:After four years, researchers observed that yields rarely, if ever, differed among the four tillage systems at any of the farms. Still, change is never easy. The study by Daigh and his team suggests that adapting conservation tillage practices will not cause yield losses. In fact, conservation tillage practices will lower on-farm costs while preserving long-term productivity."These results may ease farmers' concerns about switching to conservation tillage," says Daigh. "Perhaps more farmers will consider if conservation tillage practices are a good fit for their operations.""I encourage farmers who are interested, but hesitant, to try conservation tillage practices on one field to get more accustomed to the new system," he says. "Then, try it out on more fields until you get your farm designed to meet your needs and goals."As always, the whole picture should be evaluated before making on-farm decisions. "It's not just about yield," says Daigh. "Economics and crop-residue for erosion protection should also guide farmer decisions."The research team continues to investigate. "We are currently looking at the incorporation of cover crops into reduced tillage practices," says Daigh.This study focused on farms with one type of tillage used per field. However, newer equipment allows for variable tillage methods at once. For example, it may be capable of vertical tillage and strip tillage at the same time. In the future, Daigh and his colleagues would like to see researchers evaluate the effects of these new technologies.Read more about this work in
|
Agriculture & Food
| 2,019 |
July 29, 2019
|
https://www.sciencedaily.com/releases/2019/07/190729111212.htm
|
New, portable tech sniffs out plant disease in the field
|
Researchers at North Carolina State University have developed portable technology that allows farmers to identify plant diseases in the field. The handheld device, which is plugged into a smartphone, works by sampling the airborne volatile organic compounds (VOCs) that plants release through their leaves.
|
"All plants release VOCs as they 'breathe,' but the type and concentration of those VOCs changes when a plant is diseased," says Qingshan Wei, an assistant professor of chemical and biomolecular engineering and corresponding author of a paper on the work. "Each disease has its own signature profile of VOCs. So, by measuring the type and concentration of VOCs being released by the plant, you can determine whether a plant is diseased and -- if it is diseased -- which disease it has."Our contribution here is the creation of a device that can be plugged into a smartphone and used to make those VOC measurements quickly in the field," says Wei, who is also a faculty member in NC State's Emerging Plant Disease and Global Food Security cluster.Current disease identification techniques rely on molecular assays, which take hours to perform and -- most importantly -- have to be done in a lab. Getting a sample to the lab, where the sample may have to wait to be tested, can delay disease identification by days or weeks."Our technology will help farmers identify diseases more quickly, so they can limit the spread of the disease and related crop damage," says Jean Ristaino, William Neal Reynolds Distinguished Professor of Plant Pathology at NC State, co-author of the paper and director of the cluster. "We are now ready to scale up the technology."Here's how the technology works. If a farmer suspects that a plant may be diseased, he or she can take a leaf from the relevant plant and place it in a test tube. The test tube is then capped for at least 15 minutes to allow the relevant VOCs to accumulate. After this incubation period, the cap is removed and the farmer uses a narrow, plastic tube to pump the VOC-laden air into a "reader" device connected to a smartphone.The air is pumped into a chamber in the reader that contains a paper strip. The paper is embedded with an array of chemical reagents that change color when they come into contact with a specific chemical group. By evaluating the resulting color pattern on the strip, users can determine the nature of any plant disease that may be affecting the plant."For this technology to work, we had to develop reagents that could be embedded in the paper strips," says Zheng Li, a postdoctoral researcher at NC State and first author of the paper. "About half of the reagents were off-the-shelf organic dyes, but the other half were gold nanoparticles that we functionalized to respond to specific chemical groups. These functionalized nanoparticles allow us to be more precise in detecting various types of VOCs.""We also had to design and build the reader device, since there is nothing like it on the market," says Wei.In proof-of-concept testing, the researchers demonstrated the device's ability to detect and classify 10 plant VOCs down to the parts-per-million level. They were able to detect the late blight pathogen that caused the Irish famine two days after tomato plants were inoculated with the pathogen. Researchers could also distinguish tomato late blight from two other important fungal pathogens that produce similar symptoms on tomato leaves. In addition, the researchers showed they could detect the pathogen Phytophthora infestans in tomato leaves with greater than 95% accuracy."We've shown that the technology works," Wei says. "There are two areas where we could make it even better. First, we would like to automate the pattern analysis using software for the smartphone, which would make it easier for farmers to make disease determinations."Second, we envision the development of customized reader strips that are designed to measure the VOCs associated with other diseases specific to a given crop. Different crops in different regions face different threats, and we could develop paper strips that are tailored to address those specific concerns."This kind of innovation is an integral part of the goals of the NC State Plant Sciences Initiative, which aims to develop new technologies that will improve food production through interdisciplinary science," Wei says.
|
Agriculture & Food
| 2,019 |
July 26, 2019
|
https://www.sciencedaily.com/releases/2019/07/190726104519.htm
|
Soil pore structure is key to carbon storage
|
Alexandra Kravchenko, Michigan State University professor in the Department of Plant, Soil and Microbial Sciences, and several of her colleagues recently discovered a new mechanism determining how carbon is stored in soils that could improve the climate resilience of cropping systems and also reduce their carbon footprints.
|
The findings, published last week in the scientific journal "Understanding how carbon is stored in soils is important for thinking about solutions for climate change," said Phil Robertson, University Distinguished Professor of Plant, Soil and Microbial Sciences, and a co-author of the study. "It's also pretty important for ways to think about soil fertility and therefore, crop production."The study was conducted through the MSU Great Lakes Bioenergy Research Center, funded by the U.S. Department of Energy, and the Kellogg Biological Station Long-term Ecological Research program funded by the National Science Foundation, or NSF, and it was supported by NSF's Division of Earth Sciences.Over a period of nine years, researchers studied five different cropping systems in a replicated field experiment in southwest Michigan. Of the five cropping systems, only the two with high plant diversity resulted in higher levels of soil carbon. Kravchenko and her colleagues used X-ray micro-tomography and micro-scale enzyme mapping to show how pore structures affect microbial activity and carbon protection in these systems, and how plant diversity then impacts the development of soil pores conducive to greater carbon storage.John Schade, from the NSF Division of Environmental Biology, said the results may transform the understanding of how carbon and climate can interact in plant and soil microbial communities."This is a clear demonstration of a unique mechanism by which biological communities can alter the environment, with fundamental consequences for carbon cycling," Schade said."One thing that scientists always tend to assume is that the places where the new carbon enters the soil are also the places where it is processed by microbes and is subsequently stored and protected," Kravchenko said. "What we have found is that in order to be protected, the carbon has to move; it cannot be protected in the same place where it enters."Scientists have traditionally believed soil aggregates, clusters of soil particles, were the principal locations for stable carbon storage.Recent evidence, however, shows that most stable carbon appears to be the result of microbes producing organic compounds that are then adsorbed onto soil mineral particles. The research further reveals that soil pores created by root systems provide an ideal habitat where this can occur.Of particular importance are soils from ecosystems with higher plant diversity. Soils from restored prairie ecosystems, with many different plant species, had many more pores of the right size for stable carbon storage than did a pure stand of switchgrass."What we found in native prairie, probably because of all the interactions between the roots of diverse species, is that the entire soil matrix is covered with a network of pores," Kravchenko said. "Thus, the distance between the locations where the carbon input occurs, and the mineral surfaces on which it can be protected is very short."So, a lot of carbon is being gained by the soil. In monoculture switchgrass the pore network was much weaker, so the microbial metabolites had a much longer way to travel to the protective mineral surfaces," explained Kravchenko.Robertson said the research may prompt farmers to focus on plant diversity when attempting to increase soil carbon storage."We used to think the main way to put more carbon in soil is to have plants produce more biomass either as roots or as residue left on the soil surface to decompose," Robertson said."What this research points out is that there are smarter ways of storing carbon than such brute force approaches. If we can design or breed crops with rooting characteristics that favor this kind of soil porosity and therefore that favor soil carbon stabilization, that would be a pretty smart way to design systems that can build carbon faster."Nick Haddad, director of the Kellogg Biological Station Long-term Ecological Research program, said research that builds from these findings will continue to discover ways to improve the sustainability of agricultural ecosystems and landscapes."Long-term research shows surprising ways that a diversity of plants can benefit the microbes needed for a resilient agricultural system," Haddad added.
|
Agriculture & Food
| 2,019 |
July 25, 2019
|
https://www.sciencedaily.com/releases/2019/07/190725130820.htm
|
Worm pheromones protect major crops
|
Protecting crops from pests and pathogens without using toxic pesticides has been a longtime goal of farmers. Researchers at Boyce Thompson Institute have found that compounds from an unlikely source -- microscopic soil roundworms -- could achieve this aim.
|
As described in research published in the May 2019 issue of Led by BTI Senior Research Associate Murli Manohar, a team around Professors Daniel Klessig and Frank Schroeder investigated the effects of a roundworm metabolite called ascr#18 on plant health.Ascr#18 is a member of the ascaroside family of pheromones, which are produced by many soil-dwelling species of roundworms for chemical communication.The researchers treated soybean (When examined several days later, the ascr#18-treated plants were significantly more resistant to the pathogens compared with untreated plants."Plant roots are constantly exposed to roundworms in the soil, so it makes sense that plants have evolved to sense the pest and prime their immune systems in anticipation of being attacked," says Schroeder.Because they boost plants' immune systems instead of killing pests and pathogens, ascarosides are not pesticides. As a result, they are likely to be much safer than many current means of pest and pathogen control."Ascarosides are natural compounds that appear to be safe to plants, animals, humans and the environment," says Klessig. "I believe they could thus provide plants more environmentally friendly protection against pests and pathogens."In previous work, Klessig and Schroeder demonstrated that ascr#18 and other ascarosides increased resistance against pest and pathogens in tomato, potato, barley and "By expanding the work to major crops, and concentrating on their most significant pathogens, this study establishes the potential for ascarosides to enhance agriculture production worldwide," says Klessig.Indeed, rice is the world's most important staple food for nearly half of the global population. Ascr#18 provided protection against Wheat is close behind rice in importance as a food staple, and ascr#18 protected it against Maize is the most widely grown grain crop throughout the Americas with great importance for food, biofuel and animal feed. Ascr#18 provided protection against Soybean is a major high-protein, oil-rich seed crop used as a food source for humans and animals. Ascr#18 protected soybeans against Phytophthora sojae, an oomycete that can kill infected plants in days, as well as the bacterial pathogen Extremely small concentrations of ascarosides are sufficient to provide plants with resistance against pathogens. Interestingly, the optimal concentration appears to be dependent on the plant species and not the pathogen.The researchers believe the reason that different plant species have different optimal dosages is likely related to the plant cell's receptors for ascr#18. Different plant species may express different amounts of ascr#18 receptors, and receptors may have varying affinities for ascarosides. Such differences would affect the amount of ascr#18 needed to trigger the plant's immune systems.The group is now working to determine the molecular mechanisms of how ascarosides prime the plant's immune systems.These discoveries are being commercialized by a BTI and Cornell-based startup company, Ascribe Bioscience, as a family of crop protection products named PhytalixTM."This work is a great example of how the Institute is leveraging our technology through new start-up ventures, an important strategic initiative at BTI," says Paul Debbie, BTI's Director of New Business Development. "The Institute is proud of the opportunity to develop innovative technology in partnership with a new company that is having a positive economic impact here in our local community and for New York State."
|
Agriculture & Food
| 2,019 |
July 25, 2019
|
https://www.sciencedaily.com/releases/2019/07/190725100458.htm
|
Microbial manufacturing: Genetic engineering breakthrough for urban farming
|
Researchers at SMART, MIT's research enterprise in Singapore, and National University of Singapore (NUS) have developed a technology that greatly accelerates the genetic engineering of microbes that can be used to manufacture chemicals used for urban farming. The new technology will result in a faster, cheaper, more accurate, and near-scarless plasmid construction, using standard and reusable parts, that is compatible with most popular DNA assembly methods.
|
Explained in a paper titled "A standard for near-scarless plasmid construction using reusable DNA parts," which will be published this month in the academic journal, Kang Zhou, a DiSTAP Principal Investigator who is also an assistant professor at the NUS Department of Chemical and Biomolecular Engineering (ChBE) and Xiaoqiang Ma, a postdoctoral associate at SMART, led the development of the technology while working on ways to support their colleagues who were working on enhancing vegetable yield in the country's urban farms. They were exploring ways on microbial fermentation which create fertilizers, nutrients and non-synthetic pesticides for urban farms, in the form of small molecules."The objective of this study was to create a technology that can engineer microbes faster and at a lower cost," said Ma. "Current technology is expensive and time-consuming. Researchers have to order customised materials from suppliers which takes a while to arrive. They also often use only 1% of the material, leading to wastage. As each material is customised, researchers have to re-order each time, which further delays and add costs to the production."The new Guanine/Thymine (GT) DNA assembly technology significantly changes things by enabling genetic engineers to reuse genetic materials. It provides a simple method to define the biological parts as standard DNA parts. Further, unlike previous attempts at creating standardised materials which have an accuracy of up to 50%, the GT technology is able to reach an accuracy of close to 90%. As a near-scarless plasmid construction, the technology is substantially faster, being able to stitch up to 7 parts to a DNA as opposed to only 2 parts for other methods of similar accuracy."Being able to provide an accuracy of close to 90% for genetic materials while connecting up to 7 parts to a DNA is a game-changer in the creation of genetic materials by using standard parts," said Zhou. "We anticipate that the huge cost and time savings will enable the development of new fermentation processes that can manufacture green chemicals to make urban farming in Singapore more efficient and safer. This technology is also applicable to all genetic engineering fields outside of agriculture, and we are actively looking at ways we can deploy it for easy access."In addition to commercialisation plans, the researchers are also planning to set up an e-commerce platform which can quickly create and distribute these genetic materials to researchers around the world. It will be the first such platform for reusable genetic engineering materials in the world.
|
Agriculture & Food
| 2,019 |
July 24, 2019
|
https://www.sciencedaily.com/releases/2019/07/190724104028.htm
|
How climate change disrupts plant-animal relationships
|
Higher mean temperatures as associated with climate change can have a severe impact on plants and animals by disrupting their mutually beneficial relationship: The pasque flower (Pulsatilla vulgaris), for example, is very sensitive to rising temperatures by flowering earlier each year, whereas one of its major pollinators, a solitary bee species, does not quite keep pace by hatching earlier. In the worst case, this may cause the seed production of the plant to decrease and impair reproduction while requiring the bee to switch to other plants to forage on to compensate for the lack of food supply.
|
This is the key finding of a new study conducted by scientists from the University of Würzburg which has been published in the journal "We studied the impact of temperature on two solitary bee species that emerge in spring and on Pulsatilla vulgaris, one of the earliest flowering plants," Sandra Kehrberger describes their experiment. The scientists were particularly interested in how different temperatures in winter and spring affect the hatching time of the European orchard bee (Osmia cornuta) and of the red mason bee (Osmia bicornis) as well as the onset of flowering in the pasque flower.The phenological synchrony of the two events, hatching and flowering, is crucial in the life of both plant and bee: "For solitary bees, it is all about the correct timing of hatching in spring when the growing season starts since already a short period of time without flowering plants that provide food can have negative consequences for the bees' survival and the number of offspring," Andrea Holzschuh explains. But the timely onset of flowering is also essential for plant species that flower at the beginning of the growing season and rely on solitary pollinators. "A lack of pollinators can have serious consequences for the plants and their reproductive success," Sandra Kehrberger adds.For their study, the scientists placed bee cocoons on eleven grassland sites in the Würzburg area. On seven grasslands, they additionally studied the effect of temperature on the onset of flowering in the pasque flower. "Because the surface temperatures of the respective grasslands were different, we were able to investigate the impact of higher temperatures as an effect of climate change on the onset of flowering in Pulsatilla vulgaris and on the hatching of the mason bees," Kehrberger says.The result was clear: As the temperatures increased, the pasque flower started to flower earlier. The emergence of the two solitary bee species lagged somewhat behind. This poses the risk that the first flowers of the pasque flower bloom in the absence of suitable pollinators. As a result, reduced viability and reproductive success could negatively affect the population size and even push a species to extinction in the long run. Climate change thus presents another risk for the native red-list species Pulsatilla vulgaris. However, this temporal mismatch can also endanger the solitary bees due to the reduced availability of nectar and pollen."Our research shows that climate change also threatens domestic plants and solitary bee species which are already under great pressure from habitat loss and intensive agriculture," Sandra Kehrberger concludes. The two scientists want to use their research results to demonstrate the scope of the threat. They hope that their findings will help to better estimate the possible consequences of climate change on plant-pollinator interactions and highlight the importance of limiting global warming to a minimum.
|
Agriculture & Food
| 2,019 |
July 24, 2019
|
https://www.sciencedaily.com/releases/2019/07/190724084543.htm
|
Rising CO2 levels could boost wheat yield but slightly reduce nutritional quality
|
Levels of atmospheric carbon dioxide (CO
|
Wheat is one of the world's most important crops; its flour is used as a major ingredient in a large variety of foods such as bread, pasta and pastries. Previously, scientists have shown that elevated COThe researchers grew wheat in greenhouses at normal (400 parts per million; ppm) or elevated (700 ppm) CO
|
Agriculture & Food
| 2,019 |
July 23, 2019
|
https://www.sciencedaily.com/releases/2019/07/190723104055.htm
|
Keeping livestock in the yard just might help your baby's immune system
|
Getting up close -- and a little dirty -- with farm animals just might help us fend off illness, say researchers who've further demonstrated the benefits of early exposure to a wide variety of environmental bacteria.
|
Scientists from The Ohio State University found that bacteria and other microbes from rural Amish babies was far more diverse -- in a beneficial way -- than what was found in urban babies' intestines. And, in a first-of-its-kind experiment, they found evidence of how a healthier gut microbiome might lead to more robust development of the respiratory immune system.The study was published this month in the journal "Good hygiene is important, but from the perspective of our immune systems, a sanitized environment robs our immune systems of the opportunity to be educated by microbes. Too clean is not necessarily a good thing," said the study's co-lead author Zhongtang Yu, a professor of microbiology in Ohio State's Department of Animal Sciences and a member of the university's Food Innovation Center.The research team collected fecal samples from 10 Ohio babies who were around 6 months to a year old. The five Amish babies all lived in rural homes with farm animals. The other five babies lived in or near Wooster, a midsize Ohio city, and had no known contact with livestock.The samples revealed important differences -- particularly a wide variation in microbes and an abundance of beneficial bacteria in the Amish babies' guts that wasn't found in their city-dwelling counterparts. The researchers expected this, based on the infants' exposure to the livestock and the fact that the Amish tend to live a relatively less-sanitized lifestyle than most other Americans."The priming of the early immune system is much different in Amish babies, compared to city dwellers," said Renukaradhya Gourapura, co-lead author of the study and a professor in Ohio State's College of Food, Agricultural and Environmental Sciences and Food Animal Health Research Program.What they really wanted to know was how these differences might affect development of the immune system, setting the groundwork for a body's ability to identify and attack diseases and its resistance to allergies and other immune-system problems. Previous studies in the U.S. Amish population and to comparable populations throughout the world have drawn a clear connection between rural life and a decrease in allergies and asthma, Gourapura said.This connection has led to a theory called the "hygiene hypothesis," which is built on the idea that hyper-clean modern life -- think antibacterial soap, ubiquitous hand sanitizer and scrubbed-clean homes and workplaces -- has led to an increase in autoimmune and allergic diseases.Given that the trillions of microbes in the human gut are known to play an important role in health and disease progression, the Ohio State researchers wanted to explore how different gut microbiomes might contribute to immune system development. To do this, they used fecal transplants from the babies in the study to colonize the guts of newborn pigs."We wanted to see what happens in early immune system development when newborn pigs with 'germ-free' guts are given the gut microbes from human babies raised in different environments," Gourapura said. "From the day of their birth, these Amish babies were exposed to various microbial species inside and outside of their homes."The researchers saw a connection between the diverse Amish gut microbes and a more-robust development of immune cells, particularly lymphoid and myeloid cells in the intestines."Indeed, there was a big difference in the generation of critical immune cells," Gourapura said.Previous research into the connection between the microbiome and immunity has been conducted in mice, and this study showed that pigs -- which have anatomy, immune systems, genetics and physiology that is more similar to humans -- are a viable option for further study, Gourapura said. This is an important step because it opens the door to better exploring details about the microbial links between the gut and the respiratory tract immune system in infants, he said."Researchers know that the gut microbiome likely plays a significant role in development of the immune system and in the onset of various metabolic processes and infectious diseases, but we need better models to discover the details of that process so that we can use that information to improve human health," Gourapura said.For instance, it could be that certain probiotics could improve gut health and immune development, Yu said.Though the primary difference between the babies in the study was their exposure to a farming environment, the researchers also noted that two of the non-Amish babies were only formula-fed, while all of the Amish babies in this study were breast-fed. Another important difference that could contribute to gut microbiome differences between the groups is that the Amish families grew and routinely ate their own produce.
|
Agriculture & Food
| 2,019 |
July 23, 2019
|
https://www.sciencedaily.com/releases/2019/07/190723085955.htm
|
Garlic on broccoli: A smelly approach to repel a major pest
|
Agricultural insect pests seek out familiar scents to find their plant hosts. However, they can also be repelled by odors from other plant species.
|
A new study from the University of Vermont published in The team applied this conceptual framework to swede midge, a tiny fly that is becoming a major problem for Northeastern growers of broccoli, kale and other cabbage-family crops. They found that particular essential oils -- garlic, spearmint, thyme, eucalyptus lemon and cinnamon bark -- were most effective at repelling the midge. The findings come as good news to organic farmers who are without an effective solution for managing the pest.While essential oils have long been used in pest management, determining which oils are effective has followed a "trial by error" approach, said senior author Yolanda Chen, associate professor in UVM's Department of Plant and Soil Science."People often think more aromatic plant oils, like mint, basil and lavender will repel insects, but usually there is no rhyme or reason for choosing," said Chen, who is also a fellow of UVM's Gund Institute for the Environment. "It turns out that as we go along the family tree, plants that are more distantly related from the host plant are generally more repellent."Swede midge is a recent invader on vegetable farms in the Northeastern United States. Midge larvae must feed on the brassica plant family in order to survive, which includes many popular vegetables like broccoli, kale, cauliflower, cabbage, brussels sprouts, kohlrabi and collards. Making a mistake and laying eggs on the wrong plant would result in the death of the midge's offspring."Smell plays a major role in host location," said Chase Stratton, the study's lead author, who recently completed his PhD at UVM. "Just one landing of one fly is enough to cause marketable damage," he said.The larvae "hijack the plant's control system" resulting in distorted growth, such as headless broccoli and cauliflower, puckered leaves, and brown scarring. Unfortunately for farmers, the damage is not observable until it's too late and the midge have already dropped off the plant. In areas where the midge has become well established, including parts of Canada, New York, and Northern Vermont, the midge can cause 100 percent crop losses.To manage the midge, conventional growers have turned to neonicotinoid insecticides, which have been implicated in honeybee decline. With no methods for killing the pest, some organic farmers have simply stopped growing vulnerable brassica crops. This led Chen and Stratton to explore new control options for organic farmers."It's hard to get away from using insecticides because they're good at killing insects," said Stratton, who is now a postdoctoral researcher at the The Land Institute in Salina, Kansas. "But plants have been naturally defending against insect herbivores for millions of years. Why are we so arrogant to think we can do it better than plants?"Fascinated by the complexity of plant odors and species interactions, Stratton identified essential oils from 18 different plants that vary in their degree of relatedness to brassica host crops. He and Chen hypothesized that oils from plants that are more distantly related to brassicas would have more diverse odors and be more repellent. Comparing the chemical structures of the odors might hold clues for predicting repellency, they thought.To test the theory, the researchers observed how female midges behaved when presented with broccoli plants that had been sprayed with each of the essential oils. They found the midges were less likely to lay their eggs on broccoli plants that had been treated with essential oils, compared to the untreated plants, and avoided flying towards certain oils more than others. In general, oils from plants that were more distantly related from brassicas on the plant family tree were more likely to repel the midge. They also found that odors that were more chemically different were also more likely to be repellent. However, the oil that was most repellent -- spearmint -- actually had odors more similar to the brassica crop."Biologically, it makes sense that midges would be able to detect and avoid these plants because the similar odors would make it easier for them to misinterpret these plants as hosts, which would be deadly for their offspring," said Stratton. "For swede midge, garlic appears to be one of the most promising repellents, particularly because certified organic products using garlic are already available for growers."The study suggests a new sustainable solution for this new invasive pest and provides a novel framework for testing pest management strategies in other species.
|
Agriculture & Food
| 2,019 |
July 22, 2019
|
https://www.sciencedaily.com/releases/2019/07/190722182130.htm
|
Parasitic plants use stolen genes to make them better parasites
|
Some parasitic plants steal genetic material from their host plants and use the stolen genes to more effectively siphon off the host's nutrients. A new study led by researchers at Penn State and Virginia Tech reveals that the parasitic plant dodder has stolen a large amount of genetic material from its hosts, including over 100 functional genes. These stolen genes contribute to dodder's ability to latch onto and steal nutrients from the host and even to send genetic weapons back into the host. The new study appears July 22, 2019, in the journal
|
"Horizontal gene transfer, the movement of genetic material from one organism into the genome of another species, is very common in microbes and is a major way that bacteria can acquire antibiotic resistance," said Claude dePamphilis, professor of biology at Penn State and senior author of the study. "We don't see many examples of horizontal gene transfer in complex organisms like plants, and when we do see it, the transferred genetic material isn't generally used. In this study, we present the most dramatic case known of functional horizontal gene transfer ever found in complex organisms."Parasitic plants like dodder cannot live on their own by generating energy through photosynthesis. Instead, they use structures called haustoria to tap into a host plant's supply of water and nutrients. Dodder wraps itself around its host plant, growing into its vascular tissue, and often feeds on multiple plants at one time. It can parasitize many different species, wild plants as well as those of agricultural and horticultural importance."Parasitic plants live very intimately in connection with their host, extracting nutrients," said dePamphilis. "But they also get genetic material in the process, and sometimes they incorporate that material into their genome. Previous studies focused on single transferred genes. Here, we used genome-scale datasets about gene expression to determine whether the large amount of genetic material coming over through horizontal gene transfer is actually being used."The research team identified 108 genes that have been added to dodder's genome by horizontal gene transfer and now seem to be functional in the parasite, contributing to haustoria structure, defense responses, and amino acid metabolism. One stolen gene even produces small segments of RNA known as micro RNAs that are sent back into the host plant, acting as weapons that may play a role in silencing host defense genes.The team used rigorous criteria to determine whether the stolen genetic material was likely to be functional: The genes had to be full length, they had to contain all the necessary parts of a gene, they had to be transcribed into an RNA sequence that later builds proteins, and they had to be expressed in relevant structures. The team also explored the evolution of these transferred genes as additional support for functionality."We compare a gene's genetic sequence with closely related genes, and look for a special signature in how that sequence evolves to tell if it's likely to be functional," said dePamphilis. "Certain kinds of mutations in a gene do not affect the protein that the gene codes for and therefore do not impact the gene's function. When we see large amounts of these kinds of mutations, as opposed to mutations that might change or disrupt the gene's function, it is strong evidence that natural selection is acting to keep the proteins intact and useful."Eighteen of the 108 genes appear in all dodder species, suggesting that these genes were originally stolen by the ancestral form of dodder and are maintained in modern species."This is the first time any study has seen evidence that horizontal gene transfers occurred early in the evolution of a parasitic group," said dePamphilis. "In this case, 18 of these genes were present in the common ancestor of all the living dodder species, which may have contributed to successful spread of these parasites."The team also identified 42 regions in the dodder genome that appear to result from horizontal gene transfer, but do not have any functional genes."Because such a huge quantity of genetic material has come over through horizontal gene transfer, we suspect that the parasitic plants cannot filter what is coming in," said dePamphilis. "But natural selection is helping maintain the useful genes and filter out the less useful segments."The researchers are currently investigating how exactly genetic material is being transferred from host to parasite. They would also like to explore whether this transfer is a one-way street, or if the host can obtain genetic material from its parasite."We'd love to know how extensive horizontal gene transfer really is," said dePamphilis. "We looked at just one of species of dodder, which is just one of over 4000 species of parasitic plants. Does horizontal gene transfer of functional genes happen to the same extent in other species? Is it possible in non-parasitic plants? In other complex organisms? This may be the tip of the iceberg."In addition to dePamphilis the research team includes first author Zhenzhen Yang, a graduate student in the Plant Biology Graduate Program at Penn State at the time of the research, as well as Penn State researchers Eric Wafula, Saima Shahid, Paula Ralph, Prakash Timilsina, Wen-bin Yu, Elizabeth Kelley, Huiting Zhang, Thomas Nate Person, Naomi Altman, and Michal Axtell; Joel McNeal at Kennesaw State University; and Virginia Tech researchers Gunjune Kim and co-corresponding author James Westwood. This work was funded in part by the National Science Foundation and the United States and Department of Agriculture. Additional support was provided by the National Institute of Food and Agriculture, the Penn State Department of Biology, and the Penn State Huck Institutes of the Life Sciences.
|
Agriculture & Food
| 2,019 |
July 22, 2019
|
https://www.sciencedaily.com/releases/2019/07/190722182055.htm
|
How fat prawns can save lives
|
Before bite-sized crustaceans like crayfish, shrimp and prawns land on our dinner plates, they first have to get fat themselves -- and it turns out they relish the freshwater snails that transmit the parasite that causes schistosomiasis, the second most devastating parasitic disease worldwide, after malaria.
|
New research led by University of California, Berkeley, scientists provides a roadmap for how entrepreneurs can harness freshwater prawns' voracious appetite for snails to reduce the transmission of these parasites, also known as "blood flukes," while still making a profit selling the tasty animals as food.The study, which appears in the journal "River prawns are common aquaculture products in settings around the world, and we know these organisms are voracious predators of the snails that transmit schistosomiasis," said UC Berkeley's Christopher Hoover, a doctoral student in the School of Public Health's Division of Environmental Health Sciences who led the study. "What has not been clear is if we could marry the economic benefits of prawn aquaculture with the disease-control activity of the prawns."Aquaculture is growing rapidly in settings around the world and has the potential to alleviate mounting pressures on wild fisheries. Freshwater prawns are already being produced in aquaculture systems around the world, from Louisiana to Thailand to Senegal and beyond.In these aquaculture systems, juvenile prawns are first raised in hatchery facilities, then stocked in waterways where schistosomiasis is transmitted, and finally harvested once they reach a marketable size. As the prawns grow, they feed on the snails that carry the schistosome parasite.The parasite is incapable of infecting the prawns themselves, and schistosomiasis is not transmitted via ingestion, so raising, harvesting and consuming prawns cannot pass along the disease.The researchers used economic and epidemiologic modeling to pinpoint the optimal points at which to stock and harvest the prawns, with the joint goals of reducing schistosomiasis transmission and generating revenue from selling harvested prawns."Our results show that there are highly beneficial configurations of prawn aquaculture systems that minimize tradeoffs between generating revenue from harvesting prawns and reducing schistosomiasis transmission," Hoover said. "We can design systems to maximize profit while having a substantial impact on disease reduction, potentially helping to lift populations out of poverty in emerging and developing economies."Schistosomiasis, also known as "snail fever," affects around 250 million people a year and kills as many as 200,000. The disease is primarily spread when people come in contact with contaminated water. While drugs are available to treat the disease, they're not enough in some settings. Because drug treatments only address the human component of the parasite's transmission cycle, people are left vulnerable to reinfection, even soon after treatment.By acting on the environmental component of the transmission cycle -- the intermediate host snail population -- prawn-based interventions can complement drug treatment, yielding greater population benefits.The model showed that, to reduce parasite loads, introducing native prawns to infected waterways was comparable to the standard approach of widescale administration of schistosomiasis-fighting drugs, and that it could decrease the parasite burden to nearly zero after 10 years.Prawns may have environmental benefits, as well, including substituting for chemical pesticides to control snail populations and restoring native biodiversity in areas where native prawn species have been decimated by dams."Chris' research contributes a new tool to our global efforts to combat schistosomiasis," said Justin Remais, head of the Division of Environmental Health Sciences and co-senior author of the study. "Poverty and schistosomiasis are intrinsically linked, and transmission of the parasite is known to stunt growth and cognitive development in children and to prevent adults from working, reinforcing poverty. By targeting transmission of the parasite itself, while also supporting a locally-sourced production system where economic benefits accrue to the community, this approach has great potential to supplement ongoing disease control campaigns that generally rely on drug treatment alone."The research team also included scientists Susanne H. Sokolow, Jonas Kemp, Andrea J. Lund, Isabel J. Jones, Fiorenza Micheli and Giulio A. De Leo of Stanford University; James N. Sanchirico of the University of California, Davis; Tyler Higginson of the Middlebury Institute of International Studies at Monterey; Gilles Riveau of the Biomedical Research Center EPLS in Senegal; Amit Savaya and Amit Sagi of Ben Gurion University of the Negev; Shawn Coyle of Kentucky State University; Chelsea L. Wood of the University of Washington; Renato Casagrandi, Lorenza Mari, and Marino Gatto of the Polytechnic University of Milan; Andrea Rinaldo and Javier Perez-Saez of the Swiss Federal Institute of Technology in Lausanne and Jason R. Rohr of the University of Notre Dame.The study was supported by grants from the National Institute of Allergy and Infectious Diseases, the National Science Foundation and the National Institute of Health's Fogarty International Center.
|
Agriculture & Food
| 2,019 |
July 22, 2019
|
https://www.sciencedaily.com/releases/2019/07/190722111912.htm
|
Understanding the drivers of a shift to sustainable diets
|
One of the 21st century's greatest challenges is to develop diets that are both sustainable for the planet and good for our bodies. An IIASA-led study explored the major drivers of widespread shifts to sustainable diets using a newly developed computational model of population-wide behavioral dynamics.
|
High meat consumption -- especially of red and processed meat -- has been linked to poor health outcomes, including diabetes, heart disease, and various cancers. Livestock farming for meat production also has a massive environmental footprint. It contributes to deforestation to make room for livestock, leads to land and water degradation and biodiversity loss, and, considering the meat industry's considerable methane emissions, creates as much greenhouse gas (GHG) emissions as all the world's cars, trucks, and airplanes combined. It therefore seems logical that several studies have demonstrated that diet change, especially lowering red meat consumption, can significantly contribute to the mitigation of climate change and environmental degradation, while also being conducive to better public health.Previous studies on diet change scenarios involving lowered meat consumption, which were mostly based on stylized diets or average consumption values, showed promising results in terms of alleviating environmental degradation. If the world's average diet, for example, became flexitarian by 2050, in other words, people started to limit their red meat consumption to one serving per week and white meat to half a portion per day, the GHG emissions of the agriculture sector would be reduced by around 50%. This seems like an easy change to make, but research shows that due to the scale of behavioral change required, most of these scenarios will be difficult to achieve. In their study published in "The human behavior aspect of such large scale diet changes have to our knowledge not been studied before in relation to the food system, although we need this information to understand how such a global change can be achieved. Our study covers this gap based on a computational model of population-wide behavioral dynamics," explains Sibel Eker, a researcher in the IIASA Ecosystems Services and Management Program and lead author of the study.Eker and her colleagues adapted the land use module of an integrated assessment model to serve as a platform from where the population dynamics of dietary changes and their environmental impacts could be explored. They drew on environmental psychology to mimic population dynamics based on prominent psychological theories and included factors such as income, social norms, climate risk perception, health risk perception, and the self-efficacy of individuals, while considering the heterogeneity of their age, gender, and education levels. They then ran the model in an exploratory fashion to simulate the dynamics of dietary shifts between eating meat and a predominantly plant-based diet at the global scale. This computational analysis allowed them to identify the main drivers of widespread dietary shifts.The results indicate that social norms -- the unwritten rules of behavior that are considered acceptable in a group or society -- along with self-efficacy are the key drivers of population-wide dietary shifts, playing an even more important role than both climate and health risk perception. The team also found that diet changes are particularly influenced by how quickly social norms spread in the young population and the self-efficacy of specifically females. Focusing on the behavior influencing factors highlighted in this study could therefore be helpful in the design of policy interventions or communication campaigns where community-building activities or empowering messages could be employed in addition to communicating information around climate and health risks related to meat consumption.According to the researchers, to their knowledge, theirs is the first coupled model of climate, diet, and behavior. The modeling framework they developed is general and can be adapted to address new research questions, thus opening the door to many potential applications to explore connections between behavior, health, and sustainability. They plan to collect more data from sources like social media to quantify their model, as well as focus on specific cases where cultural values and traditions also play an important role in whether people are willing to adapt their behavior or not."We can use models to explore the social and behavioral aspects of climate change and sustainability problems in the same way as we explore the economic and environmental dimensions of our world. In this way, we get a better understanding of what works to steer the lifestyle changes required for sustainability and climate change mitigation. As lifestyle change is a key driver of climate change mitigation, this modeling exercise can be seen as an example of how we can integrate human behavior and lifestyle changes into integrated assessment models for a richer scenario exploration," concludes Eker.
|
Agriculture & Food
| 2,019 |
July 22, 2019
|
https://www.sciencedaily.com/releases/2019/07/190722105944.htm
|
Scientists make fundamental discovery to creating better crops
|
A team of scientists led by the Department of Energy's Oak Ridge National Laboratory have discovered the specific gene that controls an important symbiotic relationship between plants and soil fungi, and successfully facilitated the symbiosis in a plant that typically resists it.
|
The discovery could lead to the development of bioenergy and food crops that can withstand harsh growing conditions, resist pathogens and pests, require less chemical fertilizer and produce larger and more plentiful plants per acre.Scientists in recent years have developed a deeper understanding of the complex relationship plants have with mycorrhizal fungi. When they are united, the fungi form a sheath around plant roots with remarkable benefits. The fungal structure extends far from the plant host, increasing nutrient uptake and even communicating with other plants to "warn" of spreading pathogens and pests. In return, plants feed carbon to the fungus, which encourages its growth.These mycorrhizal symbioses are believed to have supported the ancient colonization of land by plants, enabling successful ecosystems such as vast forests and prairies. An estimated 80% of plant species have mycorrhizal fungi associated with their roots."If we can understand the molecular mechanism that controls the relationship between plants and beneficial fungi, then we can start using this symbiosis to acquire specific conditions in plants such as resistance to drought, pathogens, improving nitrogen and nutrition uptake and more," said ORNL molecular geneticist Jessy Labbe. "The resulting plants would grow larger and need less water and fertilizer, for instance."Finding the genetic triggers in a plant that allow the symbiosis to occur has been one of the most challenging topics in the plant field. The discovery, described in The scientists were studying the symbiosis formed by certain species of "Experimental validation is the key to this discovery as genetic mapping revealed statistical associations between the symbiosis and this gene, but experimental validations provided a definitive answer that it is this particular gene that controls the symbiosis," said ORNL plant molecular biologist Jay Chen.The researchers chose "We showed that we can convert a non-host into a host of this symbiont," said ORNL quantitative geneticist Wellington Muchero. "If we can make Scientists from the University of Wisconsin-Madison, the Universite de Lorraine in France, and the HudsonAlpha Institute for Biotechnology in Alabama also contributed to the project. The work was supported by DOE's Office of Science, DOE's Center for Bioenergy Innovation (CBI) and its predecessor the BioEnergy Science Center (BESC). One of CBI's key goals is to create sustainable biomass feedstock crops using plant genomics and engineering. Both BESC and CBI have developed experimental and computational approaches that accelerate the identification of gene function in plants."This is a remarkable achievement that could lead to the development of bioenergy crops with the ability to survive and thrive on marginal, non-agricultural lands," said CBI director Jerry Tuskan. "We could target as much as 20-40 million acres of marginal land with hardy bioenergy crops that need less water, boosting the prospects for successful rural, biobased economies supplying sustainable alternatives for gasoline and industrial feedstocks."
|
Agriculture & Food
| 2,019 |
July 18, 2019
|
https://www.sciencedaily.com/releases/2019/07/190718085308.htm
|
Rising CO2, climate change projected to reduce availability of nutrients worldwide
|
One of the biggest challenges to reducing hunger and undernutrition around the world is to produce foods that provide not only enough calories but also make enough necessary nutrients widely available. New research finds that, over the next 30 years, climate change and increasing carbon dioxide (CO
|
"We've made a lot of progress reducing undernutrition around the world recently but global population growth over the next 30 years will require increasing the production of foods that provide sufficient nutrients," explained Senior Scientist at the International Food Policy Research Institute (IFPRI) and study co-author Timothy Sulser. "These findings suggest that climate change could slow progress on improvements in global nutrition by simply making key nutrients less available than they would be without it."The study, "A modeling approach combining elevated atmospheric COUsing the IMPACT global agriculture sector model along with data from the Global Expanded Nutrient Supply (GENuS) model and two data sets on the effects of COImprovements in technology, and markets effects are projected to increase nutrient availability over current levels by 2050, but these gains are substantially diminished by the negative impacts of rising concentrations of carbon dioxide.While higher levels of COThe effects are not likely to be felt evenly around the world, however, and many countries currently experiencing high levels of nutrient deficiency are also projected to be more affected by lower nutrient availability in the future.Nutrient reductions are projected to be particularly severe in South Asia, the Middle East, Africa South of the Sahara, North Africa, and the former Soviet Union -- regions largely comprised of low- and middle-income countries where levels of undernutrition are generally higher and diets are more vulnerable to direct impacts of changes in temperature and precipitation triggered by climate change."In general, people in low- and middle-income countries receive a larger portion of their nutrients from plant-based sources, which tend to have lower bioavailability than animal-based sources," said Robert Beach, Senior Economist and Fellow at RTI International and lead author of the study.This means that many people with already relatively low nutrient intake will likely become more vulnerable to deficiencies in iron, zinc, and protein as crops lose their nutrients. Many of these regions are also the ones expected to fuel the largest growth in populations and thus requiring the most growth in nutrient availability.The impact on individual crops can also have disproportionate effects on diets and health. Significant nutrient losses in wheat have especially widespread implications. "Wheat accounts for a large proportion of diets in many parts of the world, so any changes in its nutrient concentrations can have substantial impact on the micronutrients many people receive," added Beach.Protein, iron, and zinc availability in wheat are projected to be reduced by up to 12% by 2050 in all regions. People will likely experience the largest decreases in protein availability from wheat in places where wheat consumption is particularly high, including the former Soviet Union, Middle East, North Africa, and eastern Europe.In South Asia, where the population's iron intake already sits well below the recommended level-India exhibits the highest prevalence of anemia in the world -- iron availability is projected to remain inadequate. What's more, elevated carbon levels push the average availability of zinc in the region below the threshold of recommended nutrient intake.Although the study's models were limited to 2050, Sulser added, "extending the analysis through the second half of this century, when climate change is expected to have even stronger impacts, would result in even greater reductions in nutrient availability."Researchers also emphasized the need for further work to build upon their findings, including additional study of climate impacts on animal sources, such as poultry, livestock, and fisheries, crops' nutritional composition, nutrient deficiencies resulting from short-term climate shocks, and technologies that could mitigate reductions in nutrient availability.Quantifying the potential health impacts for individuals also requires a consideration of the many factors beyond food consumption -- including access to clean water, sanitation, and education -- that influence nutrition and health outcomes."Diets and human health are incredibly complex and difficult to predict, and by reducing the availability of critical nutrients, climate change will further complicate efforts to eliminate undernutrition worldwide," Sulser noted.
|
Agriculture & Food
| 2,019 |
July 18, 2019
|
https://www.sciencedaily.com/releases/2019/07/190718112434.htm
|
Genetic control for major agricultural weeds?
|
Waterhemp and Palmer amaranth, two aggressive weeds that threaten the food supply in North America, are increasingly hard to kill with commercially available herbicides. A novel approach known as genetic control could one day reduce the need for these chemicals. Now, scientists are one step closer.
|
In a study published today in The researchers' goal is to one day introduce genetically modified male plants into a population to mate with wild females. Modified male plants would contain a gene drive, a segment of DNA coding for maleness, which would be passed on to all its offspring, and their offspring, and so on. Ultimately, all plants in a given population would become male, reproduction would cease, and populations would crash.It's a controversial strategy, but Pat Tranel, the U of I scientist leading the project, says they're still in the very early stages."It's important to emphasize that we are not at the point of releasing genetically modified waterhemp and Palmer. We are doing basic research that could inform how we could do that," says Tranel, professor and associate head of the Department of Crop Sciences in the College of Agricultural, Consumer and Environmental Sciences at U of I.He adds that the team hasn't found the specific gene or genes for maleness in either species. Instead, they identified small genetic sequences associated with a male region, presumably on a particular chromosome. They think the specific gene(s) for maleness lies somewhere within that region.In the study, the researchers grew 200 plants of each species and each sex, then extracted DNA and determined whether any sequences were unique to a given sex."We found sequences present in waterhemp and Palmer males that were not found in females, but no female-specific sequences. Then we took known males from other populations and looked for the sequences -- they were there," Tranel says. "Our sequences not only worked, they confirmed males are the heterogametic sex in these plants," Tranel says.In humans, males have an X and a Y chromosome, and male gametes, sperm, contribute either an X or a Y to the next generation. Females have two X chromosomes, and every egg carries an X. Males are heterogametic; females, homogametic. Similarly, male waterhemp and Palmer amaranth plants produce pollen with either the male-specific Y region or not."The fact that males are the heterogametic sex suggests that maleness is dominant. That's good in that it's easier to control the trait (maleness) if the gene for that trait is dominant," Tranel explains. "When we get to the point of identifying the specific genes for maleness, they would be an obvious target for a gene drive where you could spread that maleness gene in the population."In the meantime, however, having a set of genetic sequences that can accurately identify males before flowering could help the researchers better understand the biology of the plants and their response to the environment. For example, Tranel says the discovery could help determine if the weeds are able to switch sexes under certain conditions or if one sex is more sensitive to herbicides. Both concepts have been proposed by previous research or anecdotal reports.In addition to pursuing these basic questions, Tranel's team is now working to find the needle in the haystack: the maleness gene within the male region. When they find it, it will take time before genetic control of waterhemp and Palmer amaranth could become a reality. And even then, Tranel says it will still be important to use all the tools in the weed management toolbox."I'd never see this as replacing all our other strategies," he says. "But it's super cool to imagine this as part of the solution."
|
Agriculture & Food
| 2,019 |
July 17, 2019
|
https://www.sciencedaily.com/releases/2019/07/190717142707.htm
|
Protecting a forgotten treasure trove of biodiversity
|
The Cerrado is the largest savanna region in South America, but compared to the Amazon Forest to the North, it does not attract much attention. It is home to an incredible diversity of large mammal species including jaguar, the endangered maned wolf, the giant anteater, giant armadillo, and marsh deer, as well as more than 10,000 species of plants, almost half of which are found nowhere else on Earth. Despite its importance as a global biodiversity hotspot, it is one of the most threatened and over-exploited regions in Brazil. In fact, today, less than 20% of the Cerrado's original area remains undisturbed and this habitat is at risk of conversion to agriculture, especially for soybean cultivation.
|
The region has been at the center of the country's recent agricultural boom, with 48% of Brazil's soybean production harvested in the Cerrado in 2015. Unlike the Amazon, where almost half of the area is under some sort of conservation protection, only 13% of the Cerrado is protected. Under Brazil's Forest Code -- an environmental law designed to protect the country's native vegetation and regulate land use -- 80% of the native vegetation on private lands in the Amazon biome has to be protected, but only 20% is required in the majority of the Cerrado. Between 2000 and 2014, almost 30% of the soy expansion in the Cerrado occurred at the expense of native vegetation. A similar proportion of soy expansion in the Amazon between 2004 and 2005 led to the implementation of the Amazon Soy Moratorium, which constitutes a zero-deforestation agreement between civil society, industry, and government that forbids the buying of soy grown on recently deforested land.In their study, the team led by IIASA researcher Aline Soterroni and Fernando Ramos from Brazil's National Institute for Space Research (INPE), endeavored to quantify the direct and indirect impacts of expanding the Amazon Soy Moratorium to the Cerrado biome in terms of avoided native vegetation conversion and consequent soybean production loss. Their findings indicate that expanding the moratorium to the Cerrado would prevent the direct conversion of 3.6 million hectares of native vegetation to soybeans between 2020 and 2050. Accounting for leakage effects -- in other words, the increase of native vegetation loss to other agricultural activities due to the expansion of soybeans over already cleared areas -- the expanded moratorium would save 2.3 million hectares of the Cerrado. Nationally, this would require a reduction in soybean cultivation area of only around 2% (or 1 million hectares), as there are at least 25.4 million hectares of land that has already been cleared in the region (mainly for pasture areas with low productivity cattle ranching) that would be suitable for agricultural expansion. This suggests that both agricultural expansion and conservation of the remaining habitat may therefore be possible."According to our model, expanding the Amazon Soy Moratorium to the Cerrado can avoid the loss of a significant amount of native vegetation while simultaneously achieving soybean production goals. We also show that the Forest Code is not enough to protect the area given its low level of legal reserve requirements and its historical lack of enforcement," explains Soterroni. "Our study presents the first quantitative analysis of expanding the soy moratorium from the Amazon to the Cerrado and could be used by traders and consumer markets to adjust their supply chains."According to the researchers, a growing number of private sector actors are already voluntarily pledging to eliminate deforestation from their supply chains. Furthermore, consumer awareness of deforestation is increasing, providing companies with incentives to adhere to the responsible sourcing of commodities. Soterroni also points out that the close relative risks of future native vegetation conversion to soy estimated for China and the EU (37.52 and 37.06 hectares per 1,000 tons annually, respectively), shows that both of these entities can play an important role regarding the responsible sourcing of soy.To preserve the biodiversity and ecosystem services provided by the remaining parts of the Cerrado, urgent action is needed. Soterroni says that to this end, a public-private policy mix would be essential to preserve the last remnants of the region and in light of the recent absence of strong environmental governance in Brazil, the expansion of the Soy Moratorium beyond the Amazon to the Cerrado might be more urgent than previously thought. The researchers urge the EU and stakeholders from other regions to encourage the expansion of conservation measures to the Cerrado and to support the call for making soy trade with Brazil more sustainable.
|
Agriculture & Food
| 2,019 |
July 17, 2019
|
https://www.sciencedaily.com/releases/2019/07/190717142355.htm
|
New tuberculosis tests pave way for cow vaccination programs
|
Skin tests that can distinguish between cattle that are infected with tuberculosis (TB) and those that have been vaccinated against the disease have been created by an international team of scientists. The traditional TB tuberculin skin test shows a positive result for cows that have the disease as well as those that have been vaccinated against the disease. By distinguishing between these two groups, the new tests will facilitate the implementation of vaccination programs that could considerably reduce the transmission of this infectious bacterial disease from cattle to cattle and humans.
|
"TB kills more people globally than any other infectious disease. In fact, three people die every minute from the disease," said Vivek Kapur, professor of microbiology and infectious diseases and Huck Distinguished Chair in Global Health, Penn State. "What is less widely known is that cattle in many low- and middle-income countries are not only infected with and suffer horribly from tuberculosis, but also represent important reservoirs for transmission of the disease to humans through the consumption of unpasteurized milk or dairy products and co-habitation with infected animals."The team created its tests -- which are described in the July 17 issue of "Our diagnostic reagent is a simple cocktail of synthetic peptides representing antigens that are present in the naturally occurring TB bacteria but not recognized by the immune system following BCG vaccination," said Sreenidhi Srinivasan, graduate student in molecular, cellular and integrative biosciences at Penn State. "These antigens, when applied to the skin, cause an immune reaction in cows that have TB, whereas no reaction occurs in animals that have been vaccinated with BCG."The publication also highlights a promising alternative test format based on a recombinant fusion protein that is comparable in performance to the peptide cocktail. This protein has been developed for the United Kingdom government to be compatible with its potential cattle vaccination program, although the peptide-based test potentially obviates regulatory hurdles in countries that place greater restrictions on the use of products from genetically modified organisms.The team assessed the usefulness of its test in cattle in the United Kingdom, Ethiopia and India."It worked beautifully, exceeding the performance of the traditional test by clearly differentiating vaccinated from infected cattle," said Kapur.Kapur noted that the BCG vaccine, which was developed in the early 1900s from the bacterium that causes disease in cattle and is the world's most widely used vaccine in humans, has remained largely unused in cattle due to the potential to complicate diagnosis. In fact, the European Union, the United States and many other countries prohibit its use in cattle mainly for this reason."While BCG rarely provides sterilizing immunity for either humans or cattle, it has been shown to be effective at preventing a substantial number of infections and protecting against the more severe forms of human TB," he said. "However, the inability to tell whether a cow has the disease or has simply been vaccinated has prevented governments from implementing cow vaccination programs, leaving both animals and humans vulnerable to infection."Instead of vaccinating cattle, many countries have used a "test and slaughter" approach to control TB in these animals. The highly successful method effectively eliminated TB in the United States nearly 100 years ago and is still used in high-income countries around the world. Unfortunately, test-and-slaughter remains unfeasible in most low- and middle-income countries, where small and marginal cattle owners cannot afford to lose what often represents their primary source of income and nutrition. Additionally, in some countries, such as India, the slaughter of cattle is illegal due to the animal's cultural and spiritual importance.Treating TB-infected cows with antibiotics is not feasible either. While humans who contract TB often can be treated -- as long as they do not contract a strain that is resistant to antibiotics -- treating cows with antibiotics is expensive and can remove the animals from their service of providing milk, sometimes for years."The novel diagnostic test we have developed has the potential to replace the current standard test that has been in use for close to a century now," said Srinivasan. "Apart from being economical and easy to manufacture and to standardize quality control, the new tests enable reliable differentiation between infected and vaccinated animals, which is one of the most important limitations of the current method. Access to such tests pave the way for implementation of vaccination as an intervention strategy in settings where test-and-cull strategies are not affordable for socioeconomic reasons."Other authors on the paper include Laurel Easterling, graduate student in animal science, Penn State; Maroudam Veerasami, director, Cisgen Biotech Discoveries Private Limited; Gareth Jones, Sabine Steinbach, and Thomas Holder, research scientists, Animal and Plant Health Agency, United Kingdom; Martin Vordermeier, team leader, Animal and Plant Health Agency, United Kingdom, and professor of immunology, University of Aberystwyth, United Kingdom; Aboma Zewude, veterinary laboratory technologist, Adis Ababa University, Ethiopia; Abebe Fromsa, associate professor, and Gobena Ameni, professor, Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Ethiopia; Douwe Bakker, technical consultant, Lelystad, The Netherlands; Nicholas Juleff, senior program officer, Bill & Melinda Gates Foundation; Glen Gifford, Chargé de Mission, World Organisation for Animal Health (OIE), France; and R.G. Hewinson, Sêr Cymru Chair, University of Aberystwyth, United Kingdom.The Bill & Melinda Gates Foundation, along with the Department for Environment, Food and Rural Affairs (Defra) and Department for International Development in the United Kingdom, supported this research.
|
Agriculture & Food
| 2,019 |
July 17, 2019
|
https://www.sciencedaily.com/releases/2019/07/190717084347.htm
|
Plant probe could help estimate bee exposure to neonicotinoid insecticides
|
Bee populations are declining, and neonicotinoid pesticides continue to be investigated -- and in some cases banned -- because of their suspected role as a contributing factor. However, limitations in sampling and analytical techniques have prevented a full understanding of the connection. Now, researchers describe in the ACS journal
|
Neonicotinoids are water-soluble insecticides that are applied to seeds or foliage. But non-target organisms such as pollinating bees can also be exposed to the substances, mainly through residues in nectar and pollen of flowering plants, which bees use to make honey. Most studies to-date have relied on correlating the presence of neonicotinoid residues in plant samples with bee declines. A few studies have measured total neonicotinoids in plants but laborious methods were used. Jay Gan and colleagues wanted to develop a simpler, more direct way to monitor neonicotinoids in living plants that would capture spatial and temporal movement of the insecticides.The researchers developed a new type of solid-phase microextraction (SPME) probe, a device that can track concentration changes over time in biological systems. SPME probes use a fiber coated with a liquid or solid to quickly extract analytes from a sample. The team developed an SPME probe that they inserted into plants through a needle, allowing repeated sampling of seven neonicotinoids in plant sap. The method was demonstrated in lettuce and soybean plants, with each sampling taking only 20 minutes. The analytes were then recovered from the probe and analyzed. This procedure allowed the researchers to quantify neonicotinoids in plants and study their movement and distribution throughout the plants over time. This method could be used to monitor movement of pesticides into flowers, nectar and pollen to pinpoint where and when maximal pesticide exposure occurs for bees and other pollinators, the researchers note.
|
Agriculture & Food
| 2,019 |
July 17, 2019
|
https://www.sciencedaily.com/releases/2019/07/190717084246.htm
|
'Intensive' beekeeping not to blame for common bee diseases
|
More "intensive" beekeeping does not raise the risk of diseases that harm or kill the insects, new research suggests.
|
Intensive agriculture -- where animals or plants are kept crowded together in very high densities -- is thought to result in higher rates of disease spreading.But researchers from the University of Exeter and the University of California, Berkeley found this is not the case for honeybees.Their study modelled the spread of multiple honeybee diseases and found that crowding many colonies together was "unlikely to greatly increase disease prevalence."However, the research only applies to existing honeybee diseases -- and the findings suggest intensive beekeeping could accelerate the spread of new diseases."Crowding of animals or crops -- or people -- into minimal space usually increases rates of disease spread," said Lewis Bartlett, of the University of Exeter and Emory University."We carried out this study because beekeepers were worried about this -- especially given the many threats currently causing the decline of bees."To our surprise, our results show it's very unlikely that crowding of honeybees meaningfully aids the spread of diseases that significantly harm honeybees."Honeybees live in close proximity to each other naturally, and our models show that adding more bees does little to raise disease risk."So, beekeepers don't need to worry about how many bees they keep together as long as there is enough food for them."The key is not whether they encounter a disease -- it's whether they are fit and healthy enough to fight it off."Although the paper says intensification of beekeeping does not boost diseases among honeybees, Bartlett points out that intensive agriculture -- especially use of pesticides and destruction of habitats -- harms bee species including honeybees.The research was partly funded by the Biotechnology and Biological Sciences Research Council and the National Institutes of Health.
|
Agriculture & Food
| 2,019 |
July 16, 2019
|
https://www.sciencedaily.com/releases/2019/07/190716095541.htm
|
An AI technology to reveal the characteristics of animal behavior only from the trajectory
|
Recording the movements of people and animals (including birds and insects) has become very easy because of the development of small and inexpensive GPS devices and video cameras. However, it is still difficult to infer what triggers such movements (for example, external stimuli and/or their mental processes) from the behavioral records.
|
In this study, Shuhei Yamazaki and colleagues have developed an artificial intelligence (AI) technology, first, to estimate an animal's behavioral state, such as "resting," "feeding," or "traveling," without human classification, and, next, to explore the characteristics of each behavioral state by comparing responses under different conditions, such as before and after experiencing a certain stimulus.This method, termed STEFTR (state estimation and feature extraction of animal behavior), enabled the researchers to estimate the behavioral states of roundworms and penguins that move approximately 1 cm in 10 min in a petri dish and several kilometers in 1 day or more in the Antarctic Ocean, respectively, by analyzing them in exactly the same way. Notably, they achieved > 90% accuracy using only tens of animal trajectories, although traditionally researchers used prior knowledge of specialists about the animal's movement and/or millions of video images of animal behavior to train AI.In the feature extraction, Yamazaki et al. revealed experience-dependent (i.e., "learning"-dependent) changes in specific behavioral aspects in worms and bats, and sexual pheromone-dependent changes in fruit flies. Moreover, they revealed changes in nerve activity that is linked to behavioral change in worms.In conclusion, the STEFTR method may make it easy to infer "important places" for animal behavior, such as nests and feeding places that are usually difficult to find, using only trajectory data of wild animals. In addition, it may help discover important brain activities related to animal behavior, thereby contributing to the progress of basic brain science.
|
Agriculture & Food
| 2,019 |
July 15, 2019
|
https://www.sciencedaily.com/releases/2019/07/190715174312.htm
|
Effectiveness of using natural enemies to combat pests depends on surroundings
|
When cabbage looper moth larvae infest a field, sustainable growers will often try to control the pests by releasing large numbers of predators, such as ladybugs. That way they can avoid spraying expensive and environmentally harmful insecticides.
|
Still, farmers have mixed results when they supplement their fields with beetles or other predators.A new study of cabbage crops in New York -- a state industry worth close to $60 million in 2017, according to the USDA -- reports for the first time that the effectiveness of releasing natural enemies to combat pests depends on the landscape surrounding the field."The landscape context can inform how to better use this strategy in field conditions," said Ricardo Perez-Alvarez, the paper's first author and a graduate student in the lab of co-author Katja Poveda, associate professor of entomology. Brian Nault, an entomology professor at Cornell AgriTech, is also a co-author.The paper, "Effectiveness of Augmentative Biological Control Depends on Landscape Context," was published in the journal The reasons behind this phenomenon are complex, and depend on interactions between local predators and those that are added, which can vary on a case-by-case basis."Landscape composition influences how predator species interact with one another and thereby mediates the potential consequences for biological pest control," Perez-Alvarez said.The study focused on cabbage crops and three cabbage pests (the larvae of the cabbage white butterfly, the diamondback moth and the cabbage looper moth), and their natural enemies. In central New York, there are 156 native predator species and seven parasitoid wasps that prey on these pests. Among these, two generalist predators are commonly used to augment fields with additional pest enemies: the spined soldier bug and the convergent ladybird beetle. These two generally complement each other well because soldier bugs feed on larvae and ladybugs feed on eggs.In the study, the researchers set up experimental plots on 11 cabbage farms in central New York, which together represented a range of surrounding landscapes from agricultural lands to natural areas.Each farm had two cabbage plots: one that was left alone so it was exposed to the naturally occurring predators, and another where soldier bugs and ladybugs were added. The researchers then collected a wide range of data that included surveys of pest and predator abundances, plant damage and final crop yields. They also conducted lab experiments to better understand the relationships between predators and how those interactions impact pest control.Given how complex these predator-predator and predator-pest interactions and their relationships to pest control can be, more study is needed to make specific recommendations to growers. Still, the paper is a first step toward understanding how landscapes influence the effects of augmenting farms with predators for pest control.The study was funded by National Institute of Food and Agriculture at the United States Department of Agriculture.
|
Agriculture & Food
| 2,019 |
July 15, 2019
|
https://www.sciencedaily.com/releases/2019/07/190715114258.htm
|
Comprehensive review of the future of CRISPR technology in crops
|
CRISPR is often thought of as "molecular scissors" used for precision breeding to cut DNA so that a certain trait can be removed, replaced, or edited, but Yiping Qi, assistant professor in Plant Science & Landscape Architecture at the University of Maryland, is looking far beyond these traditional applications in his latest publication in
|
With this new paper, Qi highlights recent achievements in applying CRISPR to crop breeding and ways in which these tools have been combined with other breeding methods to achieve goals that may not have been possible in the past. He aims to give a glimpse of what CRISPR holds for the future, beyond the scope of basic gene editing."When people think of CRISPR, they think of genome editing, but in fact CRISPR is really a versatile system that allows you to home in on a lot of things to target, recruit, or promote certain aspects already in the DNA," says Qi. "You can regulate activation or suppression of certain genes by using CRISPR not as a cutting tool, but instead as a binding tool to attract activators or repressors to induce traits."Additionally, Qi discusses the prospect of recruiting proteins that can help to visualize DNA sequences, and the potential for grouping desirable traits together in the genome. "I call this gene shuffling," says Qi. "This is designed to move very important trait genes close to each other to physically and genetically link them so they always stick together in traditional crossbreeding, making it much easier to select for crops with all the traits you want."These are just some of the examples of future directions Qi hopes to cultivate and draw more attention to with this paper. "I hope this review [in This includes the process of taking CRISPR applications in animals and humans and applying them to crops in ways that haven't been done before. For example, CRISPR technology has already enhanced screenings for genes and traits in human health by using a library of tens of thousands of guide molecules that are tailored for targeting selected gene sets at the genome scale. This system could be potentially used in plants to screen for traits that contribute to disease and pest resistance, resiliency, and crop yield. "This not only helps with breeding, but also helps categorize gene functioning much more easily," says Qi. "Mostly, these studies have been done in human cells, and crops are lagging behind. I see that as one future aspect of where plant science can harness some of these different applications, and my lab has already been doing some of this work."Qi's lab has published multiple original research papers this year that highlight some of the differences for CRISPR applications in human and plant cells. Earlier this year in Molecular Plant, Qi, his graduate student, interns, and collaborators published findings testing the targeting scope and specificity of multiple CRISPR Cas9 variants. Qi's team sought to prove or disprove claims made in humans about the fidelity and specificity of these tools in rice. "Not all claims that are made for CRISPR functionality in humans and animals are going to be true or applicable in plants, so we are looking at what works and what we can do to optimize these tools for crops."Another recent paper in BMC Biology as part of a collaborative research effort investigated temperature as a method of improving efficiency of CRISPR Cas12a genome editing in rice, maize, and Arabidopsis, which was found to need higher than ambient temperatures to boost editing efficiency. "Human cells are always maintained at higher temperature which may be optimal for CRISPR to work, but is pretty hot for plants," says Qi. "We have to explore how that temperature plays a role for CRISPR applications in other species."Qi also published the first ever book dedicated entirely to Plant Genome Editing with CRISPR Systems, highlighting cutting-edge methods and protocols for working with CRISPR in a variety of crops."This book is really gathering together specific applications for many different plant systems, such as rice, maize, soybeans, tomatoes, potatoes, lettuce, carrots -- you name it -- so that people working in their own plant of interest may find some chapters quite relevant. It is designed as a protocol book for use in the lab, so that anybody new to the field should be able to figure out how to work with CRISPR in their particular plant." Qi was contacted by the publisher in the United Kingdom, Humana Press, to produce and edit the book. It was released earlier this year as part of the Methods in Molecular Biology book series, a prominent and respected series in the field."How to feed the world down the road -- that's what motivates me every day to come to work," says Qi. "We will have 10 billion people by 2050, and how can we sustain crop improvement to feed more people sustainably with climate change and less land? I really think that technology should play a big role in that."
|
Agriculture & Food
| 2,019 |
July 15, 2019
|
https://www.sciencedaily.com/releases/2019/07/190715105817.htm
|
A legal framework for vector-borne diseases and land use
|
Vector-borne diseases cause more than 700,000 deaths and affect hundreds of millions of people per year. These illnesses -- caused by parasites, viruses, and bacteria transmitted by insects and animals -- account for more than 17% of all infectious diseases on Earth.
|
While many emerging infectious diseases (EIDs) are preventable through informed protective measures, the way that humans alter our landscape -- such as for farming and urban growth -- is making this task more difficult.Human-induced land use change is the primary driver of EIDs, including those carried by mosquitoes such as malaria, dengue, Zika, EEE, and West Nile. Why, then, does land-use planning often fail to recognize the effects these changes have on the risk of spreading disease?Patricia Farnese, an associate professor of law at the University of Saskatchewan, will offer a legal perspective on infectious disease management with specific reference to vector-borne diseases at the Ecological Society of America's Annual Meeting in August."My goal is both to educate and to discuss how land-use planning can be different," says Farnese, who teaches property, agriculture, and wildlife law and researches ethical questions that arise when conservation and human rights collide.When humans use more land for agriculture like farming, new pathways are introduced for EIDs to spread. Farnese says providing farm animals with sanitary, appropriate living conditions that are not overcrowded is extremely important. "You also want to make sure that farm animals are separated from wild animals," she says. "The spread of chronic wasting disease (CWD), for instance, is directly tied to the contact between wild animals and with captive animals that have CWD. It's not transferable to humans, although there are fears that it will mutate and infect humans or animals in agriculture."People who are the poorest often suffer the most. The growth of urban slums is another land use change largely driving the spread of EIDs. Unsafe water, poor housing conditions and poor sanitation are standard conditions for those living in urban slums that contribute to the spread of EIDs. Inadequate waste management allows mosquitoes to easily breed and spread disease to large populations.Farnese says there are many reasons that land-use planning often fails take human health into consideration and to recognize the risk of spreading disease, including the fact that the legal jurisdictions for health and land-use are often not held by the same level of government. Most land-use planning occurs at the local level, while action to prevent and mitigate infectious diseases often needs to be taken at a broader scale to be effective.The biggest failing, according to Farnese, is that there are no legal mechanisms requiring land-use planning to do so. "Current frameworks for land-use planning are very good at protecting current uses, especially in urban areas," she explains. "But what of the rest of the environment? Rarely do places other than extraordinary places, such as national parks, get land-use planning attention."In the face of increasing EIDs as land-uses change in response to a changing climate, Farnese calls for improved models and legal guidelines for land-use planning that are adaptive to future uses and that address natural landscapes outside of urban areas. Specifically, she calls for legal frameworks that mandate both planning at the landscape scale and consideration of not just desired human land-uses, but also how they impact disease risk.
|
Agriculture & Food
| 2,019 |
July 15, 2019
|
https://www.sciencedaily.com/releases/2019/07/190715105224.htm
|
More farmers, more problems: How smallholder agriculture is threatening the western Amazon
|
A verdant, nearly roadless place, the Western Amazon in South America may be the most biologically diverse place in the world. There, many people live in near isolation, with goods coming in either by river or air. Turning to crops for profit or sustenance, farmers operate small family plots to make a living.
|
Unfortunately, these farmers and their smallholder agriculture operations pose serious threats to biodiversity in northeastern Peru, according to a team of researchers led by Princeton University.After conducting a large-scale study of birds and trees, the researchers found that human activities are destroying this tropical forest wilderness -- and the problem will likely only get worse. Their findings were recently published in the journal Many scientists have assumed the impacts of small-scale farming are not too harmful to wildlife, at least not compared with the wholesale clearing of forests for pastures and soybean fields, which is happening in the Eastern Amazon. But this study shows how the far less intrusive actions of small-scale farmers are nonetheless deadly to biodiversity."Smallholder agriculture turns out to be a very serious threat to biodiversity, closer in impact to clearing the forests for cattle pastures than we had imagined." said David Wilcove, a professor of ecology and evolutionary biology, public affairs, and the Princeton Environmental Institute. "What's worse is that smallholder agriculture is the dominant form of land-use change in Western Amazonia, and it is likely to get more widespread in the coming decades.""We wanted to know how tropical biodiversity responds to smallholder agriculture across the wide range of different forest habitats that typify tropical forest landscapes, and the Western Amazon is a good place to ask these questions," said lead author Jacob Socolar, a 2016 graduate alumnus who conducted the work as a Ph.D. student in Wilcove's lab. He is now a postdoctoral researcher with the Norwegian University of Life Sciences and the University of Sheffield."We called the paper, 'overlooked biodiversity loss' because the situation at the landscape scale is worse than we would've guessed by studying one habitat at a time," he said. Socolar and Wilcove teamed up with botanist Elvis Valderrama Sandoval from the Universidad Nacional de la Amazonía Peruana.The team conducted their fieldwork in the Amazonian lowlands of Loreto Department in Peru. There, they focused on four habitats -- upland forests, floodplain forests, white-sand forests and river islands -- where slash-and-burn agriculture is taking place. They also looked at relatively untouched areas of forest as a basis for comparison.They sampled birds and trees, two groups they felt would be complementary in how they would respond to changes across the land. Likewise, birds are Socolar's expertise, and Sandoval is a skilled botanist.Sampling birds can be difficult, Socolar said, especially in this region of Peru, which harbors the greatest number of bird species per acre of anywhere on earth. In 10-minute increments, Socolar recorded all of the bird species in the area based on sight or sound. His final count was 455 bird species, making it among the richest single-observer point-count datasets ever assembled.Trees are just as tricky, given there are well over 1,000 species in the Peruvian landscape. In their field experiment, the team was able to identify 751 tree species on their study sites.Different patterns emerged for the birds and trees, creating a seeming contradiction that became a feature of the study, Socolar explained.In the slashed-and-burned areas, the team found many species of birds. In fact, the farmed sites sometimes had more species than the comparable intact sites. When all sites were tallied, however, the intact sites turned out to have significantly more bird species than the disturbed ones, because all disturbed sites shared a limited pool of species, while intact sites varied in their species composition across different forest habitats.Trees, on the other hand, exhibited a far less subtle pattern: there were simply far fewer tree species persisting on the cleared land than in the intact forests, and this held even after the scientists used statistical tests to account for the fact that disturbed sites have fewer individual trees than intact forests. With the reduction in the number of tree species in the disturbed sites, the scientists predict there will be fewer insects and other small animals as well, which could have major impacts to the ecosystem.The results have significant conservation policy implications. First, this area of the Amazon will probably not remain relatively roadless forever, Socolar said, and with more roads will come more farmers. This means it's important to carefully manage remote, protected areas to ensure that ongoing infrastructure development does not cause them to be overrun by smallholders. Given the majority of these farmers are poor, there could also be opportunities to link conservation with efforts to improve rural development and decrease poverty."Even though smallholder agriculture supports high biodiversity at small spatial scales, we cannot lose vigilance regarding the overall threat posed by smallholder expansion," Socolar said. "If we do, we pay a price in extinctions. We want this study to serve as a larger warning. It's probably not just a fluke of the Amazon -- these findings could extend to other habitats. We're lucky to work in a place where there is still plenty of land to go around for both farming and conservation. Being proactive is possible, moral and reasonable."
|
Agriculture & Food
| 2,019 |
July 12, 2019
|
https://www.sciencedaily.com/releases/2019/07/190712120230.htm
|
Early arrival of spring disrupts the mutualism between plants and pollinators
|
Gaku Kudo of Hokkaido University and Elisabeth J. Cooper of the Arctic University of Norway have demonstrated that early snowmelt results in the spring ephemeral Corydalis ambigua flowering ahead of the emergence of its pollinator, the bumblebee.
|
Global warming has affected the phenology of diverse organisms, such as the timing of plant flowering and leafing, animal hibernation and migration. This is particularly so in cold ecosystems, increasing the risk of disturbing mutual relationships between living organisms. It could also affect the relationship between plants and insects that carry pollen, but few studies have been conducted and the subject remains largely unknown.The researchers examined Corydailis ambigua growing in cold-temperature forests in Hokkaido in northern Japan, and bumblebees, which collect nectar from the flowers. Usually the bloom of the flowers and emergence of the bumblebees are in sync.They monitored the plant and insect for 19 years in a natural forest of Hokkaido, recording the timing of snowmelt, flowering and emergence of bumblebees as well as the seed-set rate. In this way, they were able to observe how the snowmelt timing and ambient temperatures affect the local phenology.Long-term monitoring revealed that snowmelt timing dictates when Corydailis ambigua flowers. The earlier the snowmelt, the earlier the flowering. The researchers also found that bumblebees, which hibernate underground during winter, become active when soil temperatures reach 6 C. When the snowmelt is early, flowering tends to occur before the bees emerge, creating a mismatch. The wider the mismatch, the lower the seed-set rate due to insufficient pollination.A snow-removal experiment also showed similar trends backing up the finding that the phenological mismatch affects the seed production of spring ephemerals."Our study suggests the early arrival of spring increases the risk of disruption to the mutualism between plants and pollinators," says Gaku Kudo. "Studying how this phenological mismatch will affect the reproduction and survival of plants and insects could give us clues to the larger question of how global warming is affecting the overall ecosystem."
|
Agriculture & Food
| 2,019 |
July 11, 2019
|
https://www.sciencedaily.com/releases/2019/07/190711200607.htm
|
Wildfires disrupt important pollination processes by moths and increase extinction risks
|
Publishing their findings today (12 July) in the journal
|
Previous studies have shown the flush of pollen-producing wildflowers after a fire can benefit the day-time pollinators such as bees and butterflies. In contrast, the team found that night-time moths, which are important but often overlooked pollinators, were much less abundant and with fewer species found after the fire.The team found that 70% of the moths caught in Portugal were transporting pollen, but in spring over 95% of moths were found to be involved in this important ecological process. In total, moths carried the pollen of over 80% of flowering plant species in the study area.However, the total amount of pollen transported by moths was five times lower at burned sites, suggesting that more frequent wildfires may disrupt night-time pollination and increase the risk of extinction of these key species.The researchers, from Newcastle University, the University of York, A Rocha Portugal and Universidade de Évora, Portugal, working with collaborators from the Centre for Ecology & Hydrology and Butterfly Conservation, also found that the moth community changed significantly at burned sites, likely due to the moths' inability to breed in burned areas if host plants are destroyed by fire.Lead author Dr Callum Macgregor from the Department of Biology, University of York, said: "Day-time pollinators, such as bees, have previously been shown to respond positively to the post-fire increase in resources of pollen and nectar, but it was not known whether night-flying pollinators, such as moths, benefit in the same way."By comparing sites within the burned area to unburned sites nearby, we found that after the fire, flowers were more abundant and represented more species, which was mainly due to increases of flowers in winter and spring. By contrast, we found that moths were much less abundant and less species rich after the fire, across all seasons."Co-lead author Paula Banza, from A Rocha Portugal and Universidade de Évora, said: "By analysing the networks of interactions between moths and plants, we showed that plant-insect communities at burned sites were less able to resist the effects of any further disturbances without suffering species extinctions."Dr Darren Evans, Reader in Ecology and Conservation at the School of Natural and Environmental Sciences at Newcastle University co-supervised the study.He said: "Given the increasing frequency of devastating wildfires we are witnessing in places such as Portugal, the United States and even British moorlands, this is a cause for concern as ecosystems may be becoming less resilient and unable to return to a functioning state."A study from 2018, led by Dr Macgregor, Dr Evans and other members of the team, has shown that moths may play a much broader role as plant pollinators than previously suspected. The research revealed that moths visit many of the same plants as bees and other pollinating insects, suggesting that plants with the capacity to be pollinated by both moths and bees may be at an advantage.
|
Agriculture & Food
| 2,019 |
July 11, 2019
|
https://www.sciencedaily.com/releases/2019/07/190711141431.htm
|
Yield-boosting stay-green gene identified from 118-year-old experiment in corn
|
A corn gene identified from a 118-year-old experiment at the University of Illinois could boost yields of today's elite hybrids with no added inputs. The gene, identified in a recent
|
Dating back to 1896, the Illinois experiment was designed to test whether corn grain composition could be changed through artificial selection, a relatively new concept introduced by Charles Darwin just 37 years earlier. Repeated selection of high- and low-protein corn lines had the intended effect within about 10 generations. As selection for the traits continued, however, additional changes were noticeable."One of the things that was noted as early as the 1930s was that the low-protein line stays greener longer than the high-protein line. It's really obvious," says Stephen Moose, professor in the Department of Crop Sciences at Illinois and co-author of the study.Staying green longer into the season can mean more yield. The plant continues photosynthesizing and putting energy toward developing grain. But, until now, no one knew the specific gene responsible for the stay-green trait in corn."The stay-green trait is like a 'fountain of youth' for plants because it prolongs photosynthesis and improves yield," says Anne Sylvester, a program director at the National Science Foundation, which funded this research. "This is a great basic discovery with practical impact."The discovery of the gene was made possible through a decade-long public-private partnership between Illinois and Corteva Agriscience. Moose and Illinois collaborators initially gave Corteva scientists access to a population derived from the long-term corn protein experiment with differences in the stay-green trait. Corteva scientists mapped the stay-green trait to a particular gene, NAC7, and developed corn plants with low expression for the trait. Like the low-protein parent, these plants stayed green longer. They tested these plants in greenhouses and fields across the country over two field seasons.Not only did corn grow just fine without NAC7, yield increased by almost 5 bushels per acre compared to conventional hybrids. Notably, the field results came without added nitrogen fertilizer beyond what farmers typically use."Collaborating with the University of Illinois gives us the opportunity to apply leading-edge technology to one of the longest running studies in plant genetics," says Jun Zhang, research scientist at Corteva Agriscience and co-author of the study. "The insights we derive from this relationship can result in more bushels without an increase in input costs, potentially increasing both profitability and productivity for farmers."Moose's team then sequenced the NAC7 gene in the high- and low-protein corn lines and were able to figure out just how the gene facilitates senescence and why it stopped working in the low-protein corn."We could see exactly what the mutation was. It seems to have happened sometime in the last 100 years of this experiment, and fortunately has been preserved so that we can benefit from it now," Moose says.He can't say for sure when the mutation occurred, because in the 1920s crop sciences faculty threw out the original seed from 1896."They had no way of knowing then that we could one day identify genes controlling these unique traits. But we have looked in other corn and we don't find this mutation," Moose says.Future potential for this innovation could include commercialized seed with no or reduced expression of NAC7, giving farmers the option for more yield without additional fertilizer inputs.Moose emphasizes the advancement couldn't have happened without both partners coming to the table."There's value to the seed industry and society in doing these long-term experiments. People ask me why university scientists bother doing corn research when companies are doing it," he says. "Well, yeah they are, and they can do things on a larger and faster scale, but they don't often invest in studies where the payoffs may take decades."
|
Agriculture & Food
| 2,019 |
July 11, 2019
|
https://www.sciencedaily.com/releases/2019/07/190711141405.htm
|
Gene identified that will help develop plants to fight climate change
|
Hidden underground networks of plant roots snake through the earth foraging for nutrients and water, similar to a worm searching for food. Yet, the genetic and molecular mechanisms that govern which parts of the soil roots explore remain largely unknown. Now, Salk Institute researchers have discovered a gene that determines whether roots grow deep or shallow in the soil.
|
In addition, the findings, published in "We are incredibly excited about this first discovery on the road to realizing the goals of the Harnessing Plants Initiative," says Associate Professor Wolfgang Busch, senior author on the paper and a member of Salk's Plant Molecular and Cellular Biology Laboratory as well as its Integrative Biology Laboratory. "Reducing atmospheric COIn the new work, the researchers used the model plant thale cress ("In order to better view the root growth, I developed and optimized a novel method for studying plant root systems in soil," says first author Takehiko Ogura, a postdoctoral fellow in the Busch lab. "The roots of The team found that one gene, called EXOCYST70A3, directly regulates root system architecture by controlling the auxin pathway without disrupting other pathways. EXOCYST70A3 does this by affecting the distribution of PIN4, a protein known to influence auxin transport. When the researchers altered the EXOCYST70A3 gene, they found that the orientation of the root system shifted and more roots grew deeper into the soil."Biological systems are incredibly complex, so it can be difficult to connect plants' molecular mechanisms to an environmental response," says Ogura. "By linking how this gene influences root behavior, we have revealed an important step in how plants adapt to changing environments through the auxin pathway."In addition to enabling the team to develop plants that can grow deeper root systems to ultimately store more carbon, this discovery could help scientists understand how plants address seasonal variance in rainfall and how to help plants adapt to changing climates."We hope to use this knowledge of the auxin pathway as a way to uncover more components that are related to these genes and their effect on root system architecture," adds Busch. "This will help us create better, more adaptable crop plants, such as soybean and corn, that farmers can grow to produce more food for a growing world population."Other authors included Santosh B. Satbhai of Salk along with Christian Goeschl, Daniele Filiault, Madalina Mirea, Radka Slovak and Bonnie Wolhrab of the Gregor Mendel Institute in Austria.
|
Agriculture & Food
| 2,019 |
July 11, 2019
|
https://www.sciencedaily.com/releases/2019/07/190711114837.htm
|
Mustering a milder mustard, broccoli, cabbage
|
The mustards, broccolis and cabbages of the world share a distinct and bitter taste. Some consider the flavor of cruciferous plants their strongest attribute. But even in India and China, where Brassicas have been cultivated for more than 4,000 years, scientists have sought to tone down the chemical compounds responsible for their pungent flavor. Turns out the same compounds that make them bitter also make them toxic at some levels.
|
Now researchers from three continents -- including biologists from Washington University in St. Louis -- have mapped the crystal structure of a key protein that makes the metabolites responsible for the bitter taste in Brassicas. A study published this month in the journal The results could be used along with ongoing breeding strategies to manipulate crop plants for nutritional and taste benefits.The new work is born of a longtime collaboration initiated by Naveen C. Bisht, staff scientist at the National Institute of Plant Genome Research, in New Delhi, India, with Joseph Jez, professor of biology in Arts & Sciences at Washington University, and Jonathan Gershenzon, of the Max Planck Institute for Chemical Ecology, in Jena, Germany."All of the Brassicas -- be it Indian mustard, Arabidopsis, broccoli or brussel sprouts -- they all make these pungent, sulphur-smelling compounds, the glucosinolates," Jez said. The compounds have long been recognized as a natural defense against pests."Plants need to fight back," Jez said. "They can't really do anything, but they can make stuff.""There's different profiles of glucosinolates in different plants," he said. "The question has always been if you could modify their patterns to make something new. If insects are eating your plants, could you change the profile and get something that could prevent crop loss?"But there are a daunting number of glucosinolates: almost 130 different kinds recognized within the Brassicas. Each plant species within the genus makes a "collection" of several different kinds of glucosinolates -- its own flavor mix -- all of which are secondary metabolites of a particular protein.Researchers have known about the central role of this protein for decades. But prior to this study, no one had ever been able to complete the x-ray crystallography necessary to map it in detail.The new work, co-led by Roshan Kumar, now a postdoctoral fellow in the Jez laboratory at Washington University, uses genetics, biochemistry and structural biology to help unravel the molecular basis for the evolution and diversification of glucosinolates."Glucosinolates are derived from amino acids," Kumar said. "Gene elongation is one of the important steps that provides most of the diversity in the glucosinolate profiles across all of the Brassicas. It decides which type of glucosinolates (the plant) is going to form."The insight gained in the new study is important step toward mustering a milder mustard, or building a bitter-free broccoli.Maybe. Mostly researchers are interested in the potential for modifying glucosinolates in seeds, not in the stems or leafy parts of Brassica plants, Kumar said.The major oilseed crop "If you decrease glucosinolates from all over the plant, it becomes susceptible to pests and pathogens," Kumar said. "That is why there is a need for smart engineering of glucosinolates."
|
Agriculture & Food
| 2,019 |
July 11, 2019
|
https://www.sciencedaily.com/releases/2019/07/190711105647.htm
|
Global farming trends threaten food security
|
Citrus fruits, coffee and avocados: The food on our tables has become more diverse in recent decades. However, global agriculture does not reflect this trend. Monocultures are increasing worldwide, taking up more land than ever. At the same time, many of the crops being grown rely on pollination by insects and other animals. This puts food security at increased risk, as a team of researchers with help from Martin Luther University Halle-Wittenberg (MLU) writes in the journal
|
The researchers analysed data from the United Nations' Food and Agriculture Organization (FAO) on the cultivation of field crops between 1961 and 2016. Their evaluation has shown that not only is more and more land being used for agriculture worldwide, the diversity of the crops being grown has declined. Meanwhile, 16 of the 20 fastest growing crops require pollination by insects or other animals. "Just a few months ago, the World Biodiversity Council IPBES revealed to the world that up to one million animal and plant species are being threatened with extinction, including many pollinators," says Professor Robert Paxton, a biologist at MLU and one of the authors of the new study. This particularly affects bees: honeybees are increasingly under threat by pathogens and pesticides, and populations of wild bees have been on the decline around the world for decades.Fewer pollinators could mean that yields are much lower or even that harvests fail completely. However, risks are not spread equally across the world. The researchers used the FAO data to create a map showing the geographical risk of crop failure. "Emerging and developing countries in South America, Africa and Asia are most affected," says Professor Marcelo Aizen of the National Council for Scientific and Technological Research CONICET in Argentina, who led the study. This is not surprising, he says, since it is precisely in these regions where vast monocultures are grown for the global market. Soy is produced in many South American countries and then exported to Europe as cattle feed. "Soy production has risen by around 30 percent per decade globally. This is problematic because numerous natural and semi-natural habitats, including tropical and subtropical forests and meadows, have been destroyed for soy fields," explains Aizen.According to the authors, current developments have little to do with sustainable agriculture, which focuses on the food security of a growing world population. And, although poorer regions of the world are at the greatest risk, the consequences of crop failure would be felt worldwide: "The affected regions primarily produce crops for the rich industrial nations. If, for example, the avocado harvest in South America fails, people in Germany and other industrial nations may no longer be able to buy them," concludes Robert Paxton, who is also a member of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig.The researchers advocate for a trend reversal: Care should be taken to diversify agriculture worldwide and make it more ecological. This means, for example, that farms in particularly susceptible countries should grow a diversity of crops. In addition, farmers all over the world would need to make the areas under cultivation more natural, for example by planting strips of flowers or hedgerows next to their fields and by providing nesting habitats on field margins. This would ensure that there are adequate habitats for insects, which are essential for sustainable and productive farming.
|
Agriculture & Food
| 2,019 |
July 10, 2019
|
https://www.sciencedaily.com/releases/2019/07/190710160843.htm
|
Food may have been scarce in ancient Chaco Canyon
|
Chaco Canyon, a site that was once central to the lives of pre-colonial peoples called Anasazi, may not have been able to produce enough food to sustain thousands of residents, according to new research. The results could shed doubt on estimates of how many people were able to live in the region year-round.
|
Located in Chaco Culture National Historic Park in New Mexico, Chaco Canyon hosts numerous small dwellings and a handful of multi-story buildings known as great houses. Based on these structures, researchers think that it was once a bustling metropolis that was home to as many as 2,300 people during its height from 1050 to 1130 AD.But Chaco also sits in an unforgiving environment, complete with cold winters, blazing-hot summers and little rainfall falling in either season."You have this place in the middle of the San Juan Basin, which is not very habitable," said Larry Benson, an adjoint curator at the CU Museum of Natural History.Benson and his colleagues recently discovered one more wrinkle in the question of the region's suitability. The team conducted a detailed analysis of the Chaco Canyon's climate and hydrology and found that its soil could not have supported the farming necessary to feed such a booming population.The findings, Benson said, may change how researchers view the economy and culture of this important area."You can't do any dryland farming there," Benson said. "There's just not enough rain."Today, Chaco Canyon receives only about nine inches of rain every year and historical data from tree rings suggest that the climate wasn't much wetter in the past.Benson, a retired geochemist and paleoclimatologist who spent most of his career working for the U.S. Geological Survey, set out to better understand if such conditions might have limited how many people could live in the canyon. In the recent study, he and Ohio State University archaeologist Deanna Grimstead pulled together a wide range of data to explore where Chaco Canyon residents might, conceivably, have grown maize, a staple food for most ancestral Pueblo peoples.They found that these pre-colonial farmers not only contended with scarce rain, but also destructive flash floods that swept down the canyon's valley floor."If you're lucky enough to have a spring flow that wets the ground ahead of planting, about three-quarters of the time you'd get a summer flow that destroys your crops," Benson said.The team calculated that Chacoans could have, at most, farmed just 100 acres of the Chaco Canyon floor. Even if they farmed all of the surrounding side valleys -- a monumental feat -- they would still have only produced enough corn to feed just over 1,000 people.The researchers also went one step further, assessing whether past Chaco residents could have supplemented this nutritional shortfall with wild game like deer and rabbits. They calculated that supplying the 185,000 pounds of protein needed by 2,300 people would have quickly cleared all small mammals from the area.In short, there would have been a lot of hungry mouths in Chaco Canyon. Benson and Grimstead published their results this summer in the For Benson, that leaves two possibilities. Chaco Canyon residents either imported most of their food from surrounding regions 60 to 100 miles away, or the dwellings in the canyon were never permanently occupied, instead serving as temporary shelters for people making regular pilgrimages.Either scenario would entail a massive movement of people and goods. Benson estimates that importing enough maize and meat to feed 2,300 people would have required porters to make as many as 18,000 trips in and out of Chaco Canyon, all on foot."Whether people are bringing in maize to feed 2,300 residents, or if several thousand visitors are bringing in their own maize to eat, they're not obtaining it from Chaco Canyon," Benson said.
|
Agriculture & Food
| 2,019 |
July 10, 2019
|
https://www.sciencedaily.com/releases/2019/07/190710151812.htm
|
Genetic breakthrough in cereal crops could help improve yields worldwide
|
A team of Clemson University scientists has achieved a breakthrough in the genetics of senescence in cereal crops with the potential to dramatically impact the future of food security in the era of climate change.
|
The collaborative research, which explores the genetic architecture of the little understood process of senescence in maize (a.k.a. corn) and other cereal crops, was published in "Senescence means 'death of a cell or an organ in the hands of the very organisms it is a part of,' " Sekhon said. "It happens pretty much everywhere, even in animals. We kill the cells we don't need. When the weather changes in fall, we have those nice fall colors in trees. At the onset of fall, when the plants realize that they cannot sustain the leaves, they kill their leaves. It is all about the economy of energy."As a result, the leaves die off after their show of color. The energy scavenged from the leaves is stored in the trunk or roots of the plant and used to quickly reproduce leaves next spring. This makes perfect sense for trees. But the story is quite different for some other edible plants, specifically cereal crops like maize, rice and wheat."These crops are tended very carefully and supplied excess nutrients in the form of fertilizers by the farmers," Sekhon said. "Instead of dying prematurely, the leaves can keep on making food via photosynthesis. Understanding the triggers for senescence in crops like maize means scientists can alter the plant in a way that can benefit a hungry world."Sekhon, whose research career spans molecular genetics, genomics, epigenetics and plant breeding, established his lab in 2014 as an assistant professor. He has played a key role in the development of a "gene atlas" widely used by the maize research community. He has published several papers in top peer-reviewed journals investigating the regulation of complex plant traits."If we can slow senescence down, this can allow the plant to stay green -- or not senesce -- for a longer period of time," Sekhon said. "Plant breeders have been selecting for plants that senesce late without fully understanding how senescence works at the molecular level."These plants, called "stay-green," live up to their name. They stay green longer, produce greater yields and are more resilient in the face of environmental factors that stress plants, including drought and heat.But even with the existence of stay-green plants, there has been little understanding about the molecular, physiological and biochemical underpinnings of senescence. Senescence is a complex trait affected by several internal and external factors and regulated by a number of genes working together. Therefore, off-the-shelf genetic approaches are not effective in fully unraveling this enigmatic process. The breakthrough by Sekhon and his colleagues was the result of a systems genetics approach.Sekhon and the other researchers studied natural genetic variation for the stay-green trait in maize. The process involved growing 400 different maize types, each genetically distinct from each other based on the DNA fingerprint (i.e., genotype), and then measuring their senescence (i.e., phenotype). The team then associated the "genotype" of each inbred line with its "phenotype" to identify 64 candidate genes that could be orchestrating senescence."The other part of the experiment was to take a stay-green plant and a non-stay-green plant and look at the expression of about 40,000 genes during senescence," Sekhon said. "Our researchers looked at samples every few days and asked which genes were gaining expression during the particular time period. This identified over 600 genes that appear to determine whether a plant will be stay-green or not."One of the big issues with each of these approaches is the occurrence of false positives, which means some of the detected genes are flukes, and instances of false negatives, which means that we miss out on some of the causal genes."Therefore, Sekhon and his colleagues had to painstakingly combine the results from the two large experiments using a "steams genetics" approach to identify some high-confidence target genes that can be further tested to confirm their role in senescence. They combined datasets to narrow the field to 14 candidate genes and, ultimately, examined two genes in detail."One of the most remarkable discoveries was that sugars appear to dictate senescence," Sekhon said. "When the sugars are not moved away from the leaves where these are being made via photosynthesis, these sugar molecules start sending signals to initiate senescence."However, not all forms of sugar found in the plants are capable of signaling. One of the genes that Sekhon and colleagues discovered in the study appears to break complex sugars in the leaf cells into smaller sugar molecules -- six-carbon sugars like glucose and fructose -- that are capable of relaying the senescence signals."This is a double whammy," Sekhon said. "We are not only losing these extra sugars made by plants that can feed more hungry mouths. These unused sugars in the leaves start senescence and stop the sugars synthesis process all together."The implications are enormous for food security. The sugars made by these plants should be diverted to various plant organs that can be used for food."We found that the plant is carefully monitoring the filling of the seeds. That partitioning of sugar is a key factor in senescence. What we found is there is a lot of genetic variation even in the maize cultivars that are grown in the U.S."Some plants fill seeds and then can start filling other parts of the plant."At least some of the stay-green plants are able to do this by storing extra energy in the stems," Sekhon said. "When the seed is harvested, whatever is left in the field is called stover."Stover can be used as animal feed or as a source of biofuels. With food and energy demand increasing, there is a growing interest in developing dual-purpose crops which provide both grain and stover. As farmland becomes scarce, plants that senesce later rise in importance because they produce more overall energy per plant.The genes identified in this study are likely performing the same function in other cereal crops, such as rice, wheat and sorghum. Sekhon said that the next step is to examine the function of these genes using mutants and transgenics."The ultimate goal is to help the planet and feed the growing world. With ever-worsening climate, shrinking land and water, and increasing population, food security is the major challenge faced by mankind," Sekhon said.
|
Agriculture & Food
| 2,019 |
July 10, 2019
|
https://www.sciencedaily.com/releases/2019/07/190710151759.htm
|
Caterpillars turn anti-predator defense against sticky toxic plants
|
A moth caterpillar has evolved to use acids, usually sprayed at predators as a deterrent, to disarm the defenses of their food plants, according to a study publishing July 10 in the open-access journal
|
Some plants such as poinsettia (Euphorbia pulcherrima) produce and store latex in specialized canals within their leaves, which can gum up and poison herbivorous insects that try to eat them. To get around this defense, larvae of the notodontid moth Theroa zethus bathe the leaf stem in an acidic secretion produced from a gland on the underside of their head, which prevents the flow of latex. To investigate this unusual strategy, the researchers filmed the caterpillar feeding, analyzed the creatures' acidic secretions, and investigated the effect of the acid at the cellular level.They found that the caterpillar's secretion is a mixture of formic and butyric acids. Histological analysis showed that the secretion physically deforms plant cell walls. Video recordings documented that before applying the acid, the caterpillars use their mandibles to scrape at and compress the leaf stem. Artificially replicating these behaviors in the laboratory, using sandpaper and binder clips, also prevented latex flow from the leaves, confirming that the caterpillars' behaviors play a part in disarming the plant's defenses.The team observed compression behaviors in six other species of notodontid moth which eat plants lacking latex canals, but only Theroa zethus used acid. The authors suggest that as the species evolved to feed on toxic plants, the caterpillars co-opted a pre-evolved anti-predator deterrent to help reduce the flow of latex and make their meal more palatable and less dangerous.Dussourd adds: "To understand if a plant is vulnerable to insect feeding, one needs to consider not just the defenses of the plant, but also the capabilities of the insect. In this study, a caterpillar deactivates the latex defense of poinsettia by secreting acid from its anti-predator gland. The caterpillar facilitates acid penetration by scraping the plant surface, then compresses the plant to rupture the latex canals internally. The combination of behavioral manipulation and acid secretion allows the caterpillar to disarm the plant often without contacting any latex exudate."
|
Agriculture & Food
| 2,019 |
July 10, 2019
|
https://www.sciencedaily.com/releases/2019/07/190710121545.htm
|
Heat, salt, drought: This barley can withstand the challenges of climate change
|
Research for the benefit of food security: A new line of barley achieves good crop yields even under poor environmental conditions. It has been bred by a research team from Martin Luther University Halle-Wittenberg (MLU), which crossed a common variety with various types of wild barley. The researchers then planted the new lines of barley in five very different locations around the world, observed the growth of the plants and analysed their genetic make-up. As the team reports in "
|
Barley, along with wheat and rice, is one of the most important cereals for human nutrition. "The demand for food is increasing worldwide, which is why the cultivation of these cereals must generate reliable crop yields. However, climate change is taking its toll on cultivation conditions worldwide and plants have to be fertilized and irrigated more frequently," says plant scientist Professor Klaus Pillen from MLU. His research team is studying how to improve common cereal varieties for years. Their approach is to cross certain industrially used barley varieties with wild barley. "Wild barley has adapted to adverse environmental conditions over millions of years. It still has a rich biodiversity today," explains Pillen. The idea is to combine the advantageous properties of both cereals.For the study, the research team crossed a typical barley variety with 25 types of wild barley. This resulted in 48 genetically different plant lines, which the research team planted at five very different locations around the world: Dundee (UK), Halle (Germany), Al Karak (Jordan), Dubai (United Arab Emirates) and Adelaide (Australia). Each of these places has its own environmental conditions: Australia and Dubai suffer from very salty, dry soils, Al Karak and Dubai from heat and drought. In Germany and UK, fields always receive additional nitrogen fertilizer in order to increase crop yields. During the cultivation period, the scientists observed the growth of the plants under environmental stress and compared the results to native varieties from a control group. "We then selected plants from our cultivation that grew particularly well on site and examined their genetic material more closely," continues Pillen. The researchers wanted to draw conclusions about the interaction between genes, the environment and crop yields."Our study also shows that the timing of plant development is extremely important. This ensures maximum crop yields even under unfavourable environmental conditions," says Pillen. By this he means, for example, the length of daylight, which varies according to latitude: the closer a place is to the equator, the shorter the duration of daily sunshine during spring and summer. This has a big impact on the development of the plants. "In northern Europe, it is more advantageous for plants to flower later. The closer you get to the equator, it's better for plants to develop much faster," explains Pillen. Based on genetic analyses of the plants, the team was also able to draw conclusions about the gene variants that cause this acceleration or delay in development.Knowing which gene variants are advantageous for which geographical regions allows plants that are particularly well adapted to the local conditions to be crossed, bred and cultivated according to the modular principle. And this is all well worth the effort: even under adverse conditions, Halle's best barley produced up to 20 percent higher yields than native plants.In follow-up projects, the research team would like to further investigate the genetic material in order to gain more detailed insights into the stress tolerance of plants. The findings from the new study can, in principle, also be applied to other cereal varieties, such as wheat and rice.
|
Agriculture & Food
| 2,019 |
July 9, 2019
|
https://www.sciencedaily.com/releases/2019/07/190709110224.htm
|
Improved model could help scientists better predict crop yield, climate change effects
|
A new computer model incorporates how microscopic pores on leaves may open in response to light -- an advance that could help scientists create virtual plants to predict how higher temperatures and rising levels of carbon dioxide will affect food crops, according to a study published in a special July 2019 issue of the journal
|
"This is an exciting new computer model that could help us make much more accurate predictions across a wide range of conditions," said Johannes Kromdijk, who led the work as part of an international research project called Realizing Increased Photosynthetic Efficiency (RIPE).RIPE, which is led by the University of Illinois, is engineering crops to be more productive without using more water by improving photosynthesis, the natural process all plants utilize to convert sunlight into energy to fuel growth and crop 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).The current work focused on simulating the behavior of what are known as stomata -- microscopic pores in leaves that, in response to light, open to allow water, carbon dioxide, and oxygen to enter and exit the plant. In 2018, the RIPE team published a paper in "We've known for decades that photosynthesis and stomatal opening are closely coordinated, but just how this works has remained uncertain," said Stephen Long, Ikenberry Endowed University Chair of Crop Sciences and Plant Biology at the University of Illinois. "With this new computer model, we have a much better tool for calculating stomatal movements in response to light."The ultimate goal, Long said, is to identify opportunities to control these stomatal gatekeepers to make drought-tolerant crops. "Now we're closing in on the missing link: How photosynthesis tells stomates when to open."Computer modeling has been a major advance in crop breeding. The father of modern genetics, Gregor Mendel, made his breakthrough discovery that pea plants inherit traits from their parents by growing and breeding more than 10,000 pea plants over eight years. Today, plant scientists can virtually grow thousands of crops in a matter of seconds using these complex computer models that simulate plant growth.Stomatal models are used together with models for photosynthesis to make wide-ranging predictions from future crop yields to crop management, such as how crops respond when there is a water deficit. In addition, these models can give scientists a preview of how crops like wheat, maize, or rice could be affected by rising carbon dioxide levels and higher temperatures."The previous version of the stomatal model used a relationship that wasn't consistent with our current understanding of stomatal movements," said Kromdijk, now a University Lecturer at the University of Cambridge. "We found that our new version needs far less tuning to make highly accurate predictions."Still, there's a lot of work to be done to show that this modified model functions in a wide variety of applications and to underpin the relationship between stomata and photosynthesis further."We have to show that this model works for a diverse range of species and locations," said former RIPE member Katarzyna Glowacka, now an assistant professor at the University of Nebraska-Lincoln. "Large-scale simulation models string together models for atmospheric turbulence, light interception, soil water availability, and others -- so we have to convince several research communities that this is an improvement that is worth making."
|
Agriculture & Food
| 2,019 |
July 8, 2019
|
https://www.sciencedaily.com/releases/2019/07/190708154106.htm
|
Tracing the roots: Mapping a vegetable family tree for better food
|
Human genetic testing has evolved over the recent decades, allowing people to find their ancestors and even determine specific percentages of their heritage. Much like the advances in human genetic testing recently popularized by commercial organizations have allowed people to gain a better understanding of their ancestry, scientists are now a step closer to determining a genetic family tree for vegetables by linking biology with computer science.
|
"Domestication of plants -- the process of adapting wild plants for human use -- happened a long time ago before we knew about genetics," said Makenzie Mabry, a doctoral student of biological sciences. "Initially in wild plants there is a big pool of genes, and domestication only uses a few of those genes. Therefore, we often miss out on other possible genes that may be better than the current ones. By identifying the ancestors of our domesticated plants, we can take the evolutionary jump and go back in time to determine the genes that weren't initially selected in domestication -- genes that could lead to more healthy or more nutritious plants or plants adapted to different climates -- and add those back into our current domesticated plants."In the new study, a team of multi-institution scientists led by the University of Missouri challenged prior theories of the origins of three vegetables -- canola, rutabaga and Siberian kale -- by mapping the genetic family tree of these leafy greens.The scientists ground up leaves from each plant, added a liquid chemical and placed the mixture in test tubes. Next, they analyzed the RNA and DNA in each plant with the help of computer science. In addition, they grew one of the plants, and independently verified the origin discovered in the test tubes."Using an analogy, some of our human genetic history comes from both our mom and dad, but other parts only come from our mom," said J. Chris Pires, a professor of biological sciences in the College of Arts and Science and investigator in the Christopher S. Bond Life Sciences Center. "Here we are trying to determine the parents of these plants, and we found that it's not the previously hypothesized mom nor dad, it's some yet to be identified species."With a recent grant from National Geographic, the team of scientists hopes to continue collecting data throughout the world to broaden their knowledge of this family tree to confidently identify the relatives of the parental species."Many people focus solely on the history of animals and people," said Hong An, a postdoctoral fellow of biological sciences. "But it's equally, if not more important, to also know the history of our food."
|
Agriculture & Food
| 2,019 |
July 8, 2019
|
https://www.sciencedaily.com/releases/2019/07/190708112514.htm
|
Potential for reduced methane from cows
|
An international team of scientists has shown it is possible to breed cattle to reduce their methane emissions.
|
Published in the journal "What we showed is that the level and type of methane-producing microbes in the cow is to a large extent controlled by the cow's genetic makeup," says one of the project's leaders and co-author Professor John Williams, from the University of Adelaide's School of Animal and Veterinary Sciences. "That means we could select for cattle which are less likely to have high levels of methane-producing bacteria in their rumen."Cattle and other ruminants are significant producers of the greenhouse gas methane -- contributing 37 per cent of the methane emissions resulting from human activity. A single cow on average produces between 70 and 120 kg of methane per year and, worldwide, there are about 1.5 billion cattle.The study comes out of a project called RuminOmics, led by the Rowett Institute at the University of Aberdeen and involving the Parco Tecnologico Padano in Italy (where Professor Williams used to work), the Ben-Gurion University of the Negev in Israel, and a number of other institutions in Europe and the US.The researchers analysed the microbiomes from ruminal fluid samples of 1000 cows, along with measuring the cows' feed intake, milk production, methane production and other biochemical characteristics. Although this study was carried out on dairy cows, the heritability of the types of microbes in the rumen should also apply to beef cattle."Previously we knew it was possible to reduce methane emissions by changing the diet," says Professor Williams. "But changing the genetics is much more significant -- in this way we can select for cows that permanently produce less methane."Professor Williams says breeding for low-methane cattle will, however, depend on selection priorities and how much it compromises selection for other desired characteristics such as meat quality, milk production or disease resistance."We now know it's possible to select for low methane production," he says. "But it depends on what else we are selecting for, and the weighting that is placed on methane -- that's something that will be determined by industry or society pressures."The researchers also found a correlation, although not as high, between the cows' microbiomes and the efficiency of milk production."We don't yet know, but if it turned out that low-methane production equated to greater efficiencies of production -- which could turn out to be true given that energy is required to produce the methane -- then that would be a win, win situation," Professor Williams says.This research, from the Davies Research Centre at the University of Adelaide's Roseworthy campus, aligns with the University's industry engagement priority in agrifood and wine, and in tackling the grand challenge of environmental sustainability.
|
Agriculture & Food
| 2,019 |
July 8, 2019
|
https://www.sciencedaily.com/releases/2019/07/190708112429.htm
|
Researchers can finally modify plant mitochondrial DNA
|
Researchers in Japan have edited plant mitochondrial DNA for the first time, which could lead to a more secure food supply.
|
Nuclear DNA was first edited in the early 1970s, chloroplast DNA was first edited in 1988, and animal mitochondrial DNA was edited in 2008. However, no tool previously successfully edited plant mitochondrial DNA.Researchers used their technique to create four new lines of rice and three new lines of rapeseed (canola)."We knew we were successful when we saw that the rice plant was more polite -- it had a deep bow," said Associate Professor Shin-ichi Arimura, joking about how a fertile rice plant bends under the weight of heavy seeds.Arimura is an expert in plant molecular genetics at the University of Tokyo and led the research team, whose results were published in Nature Plants. Collaborators at Tohoku University and Tamagawa University also contributed to the research.Researchers hope to use the technique to address the current lack of mitochondrial genetic diversity in crops, a potentially devastating weak point in our food supply.In 1970, a fungal infection arrived on Texas corn farms and was exacerbated by a gene in the corn's mitochondria. All corn on the farms had the same gene, so none were resistant to the infection. Fifteen percent of the entire American corn crop was killed that year. Corn with that specific mitochondrial gene has not been planted since."We still have a big risk now because there are so few plant mitochondrial genomes used in the world. I would like to use our ability to manipulate plant mitochondrial DNA to add diversity," said Arimura.Most farmers do not save seeds from their harvest to replant next year. Hybrid plants, the first-generation offspring of two genetically different parent subspecies, are usually hardier and more productive.To ensure farmers have fresh, first-generation hybrid seeds each season, agricultural supply companies produce seeds through a separate breeding process using two different parent subspecies. One of those parents is male infertile -- it cannot make pollen.Researchers refer to a common type of plant male infertility as cytoplasmic male sterility (CMS). CMS is a rare but naturally occurring phenomenon caused primarily by genes not in the nucleus of the cells, but rather the mitochondria.Green beans, beets, carrots, corn, onions, petunia, rapeseed (canola) oil, rice, rye, sorghum, and sunflowers can be grown commercially using parent subspecies with CMS-type male infertility.Plants use sunlight to produce most of their energy, through photosynthesis in green-pigmented chloroplasts. However, chloroplasts' fame is overrated, according to Arimura."Most of a plant isn't green, only the leaves above the ground. And many plants don't have leaves for half the year," said Arimura.Plants get a significant portion of their energy through the same "powerhouse of the cell" that produces energy in animal cells: the mitochondria."No plant mitochondria, no life," said Arimura.Mitochondria contain DNA completely separate from the cell's main DNA, which is stored in the nucleus. Nuclear DNA is the long double-helix genetic material inherited from both parents. The mitochondrial genome is circular, contains far fewer genes, and is primarily inherited only from mothers.The animal mitochondrial genome is a relatively small molecule contained in a single circular structure with remarkable conservation between species."Even a fish's mitochondrial genome is similar to a human's," said Arimura.Plant mitochondrial genomes are a different story."The plant mitochondrial genome is huge in comparison, the structure is much more complicated, the genes are sometimes duplicated, the gene expression mechanisms are not well-understood, and some mitochondria have no genomes at all -- in our previous studies, we observed that they fuse with other mitochondria to exchange protein products and then separate again," said Arimura.To find a way to manipulate the complex plant mitochondrial genome, Arimura turned to collaborators familiar with the CMS systems in rice and rapeseed (canola). Prior research strongly suggested that in both plants, the cause of CMS was a single, evolutionarily unrelated mitochondrial gene in rice and in rapeseed (canola): clear targets in the perplexing maze of plant mitochondrial genomes.Arimura's team adapted a technique that had previously edited mitochondrial genomes of animal cells growing in a dish. The technique, called mitoTALENs, uses a single protein to locate the mitochondrial genome, cut the DNA at the desired gene, and delete it."While deleting most genes creates problems, deleting a CMS gene solves a problem for plants. Without the CMS gene, plants are fertile again," said Arimura.The fully fertile four new lines of rice and three new lines of rapeseed (canola) that researchers created are a proof of concept that the mitoTALENs system can successfully manipulate even the complex plant mitochondrial genome."This is an important first step for plant mitochondrial research," said Arimura.Researchers will study the mitochondrial genes responsible for plant male infertility in more detail and identify potential mutations that could add much-needed diversity.
|
Agriculture & Food
| 2,019 |
July 8, 2019
|
https://www.sciencedaily.com/releases/2019/07/190708112427.htm
|
Grazing animals drove domestication of grain crops
|
Many familiar grains today, like quinoa, amaranth, and the millets, hemp, and buckwheat, all have traits that indicate that they coevolved to be dispersed by large grazing mammals. During the Pleistocene, massive herds directed the ecology across much of the globe and caused evolutionary changes in plants. Studies of the ecology and growing habits of certain ancient crop relatives indicate that megafaunal herds were necessary for the dispersal of their seeds prior to human intervention. Understanding this process is providing scientists with insights into the early domestication of these plants.
|
The domestication of small-seeded annuals involved an evolutionary switch from dispersal through animal ingestion to human dispersal. Those are the findings of a new study by Robert Spengler, director of the Paleoethnobotany Laboratories at the Max Planck Institute for the Science of Human History, and Natalie Mueller, a National Science Foundation fellow at Cornell University, published in During the mid-Holocene (7,000-5,000 years ago), in ecologically rich river valleys and grasslands all around the world, people started to cultivate small plants for their seed or grain. Wheat, barley, and rice are some of the earliest plants to show signs of domestication and scientists have extensively studied the domestication process in these large-seeded cereal crops. Researchers know significantly less about the domestication of small-seeded grain crops, such as quinoa, amaranth, buckwheat, the millets, and several now-lost crops domesticated in North America. The wild ancestors of these crops have small seeds with indigestible shells or seed coats. Today, these wild plants exist in small fragmentary patches dispersed across huge areas -- the fact that they do not grow in dense clusters, like the ancestors of wheat and rice, would seem to have made these crop ancestors unappealing targets for foragers. The small seed sizes and hard seed shells, combined with the lack of dense wild populations, led many researchers to argue that they must have been a famine food.Foraging enough wild seeds from these varieties to grind into flour to bake a loaf of bread would take weeks, especially for rarer or endangered crop ancestors. So why did early foragers focus so heavily on these plants and eventually adopt them as crops?Spengler and Mueller present a new model, suggesting that when humans first encountered these plants, they would have grown in dense stands created by grazing megafauna, making them easy to harvest. As humans began to cultivate these plants, they took on the functional role of seed dispersers, and eventually the plants evolved new traits to favor farming and lost the old traits that favored being spread by herd animals. The earliest traits of domestication, thinning or loss of indigestible seed protections, loss of dormancy, and increased seed size, can all be explained by to the loss of the ruminant dispersal process and concomitant human management of wild stands.Spengler and Mueller have been interested in plant domestication since graduate school, when they studied under Dr. Gayle Fritz, one of the first scholars to recognize the importance of the American Midwest as a center of crop domestication. Despite decades of research into the nature of plant domestication in North America, no one recognized that the true key was the massive bison herds. The plants that were domesticated, what Mueller calls the "Lost Crops," would have been dispersed by bison in large swaths, making them easy to collect by ancient people and perhaps encouraging these communities to actively plant them themselves. When Europeans exterminated the herds, the plants that relied on these animals to disperse their seeds began to diminish as well. Because the wild ancestors of these lost crops are rare today and the bison herds are effectively extinct, researchers have overlooked this important coevolutionary feature in the domestication process.However, this process is not unique to the American Midwest and the researchers suggest that there may be links between buckwheat domestication and yak herding in the Himalaya and amaranth domestication and llama herding in the Andes. The authors have identified parallel patterns in rangeland ecology studies, noting that heavy herd animal herbivory can homogenize vegetation communities. For example, heavy pastoralist grazing in the mountains of Central Asia causes many plants to die, but certain plants with adaptations for dispersal by animals thrive. The depositing of plant seeds in nutrient rich dung leads to ecological patches, often called hot spots, that foragers can easily target for seed collecting.For over a century, scholars have debated why early foragers targeted small-seeded annuals as a major food source (eventually resulting in their domestication). Today, the progenitors of many of these crops have highly fragmentary populations and several are endangered or extinct. Likewise, without large dense homogenous stands of these plants in the wild, such as what exists in the wild for the progenitors of large-seeded cereal crops, it would have been impossible to harvest their seeds. The conclusions that Spengler and Mueller draw help explain why people targeted these plants and were able to domesticate them. "Small-seeded annuals were domesticated in most areas of the world," explains Spengler. "So the ramifications of this study are global-scale. Scholars all over the world will need to grapple with these ideas if they want to pursue questions of domestication."Spengler and Mueller are continuing their research into the role that grazing animals played in plant domestication. "Currently, we're studying the ecology of fields where modern herd animals graze as proxies to what the ecology would have looked like during the last Ice Age, when large herds of bison, mammoths, and wooly horses dictated what kinds of plants could grow across the American Midwest and Europe," explains Spengler. "We hope these observations will provide even greater insight into the process of domestication all over the world."
|
Agriculture & Food
| 2,019 |
July 7, 2019
|
https://www.sciencedaily.com/releases/2019/07/190707215819.htm
|
Robot uses machine learning to harvest lettuce
|
A vegetable-picking robot that uses machine learning to identify and harvest a commonplace, but challenging, agricultural crop has been developed by engineers.
|
The 'Vegebot', developed by a team at the University of Cambridge, was initially trained to recognise and harvest iceberg lettuce in a lab setting. It has now been successfully tested in a variety of field conditions in cooperation with G's Growers, a local fruit and vegetable co-operative.Although the prototype is nowhere near as fast or efficient as a human worker, it demonstrates how the use of robotics in agriculture might be expanded, even for crops like iceberg lettuce which are particularly challenging to harvest mechanically. The results are published in Crops such as potatoes and wheat have been harvested mechanically at scale for decades, but many other crops have to date resisted automation. Iceberg lettuce is one such crop. Although it is the most common type of lettuce grown in the UK, iceberg is easily damaged and grows relatively flat to the ground, presenting a challenge for robotic harvesters."Every field is different, every lettuce is different," said co-author Simon Birrell from Cambridge's Department of Engineering. "But if we can make a robotic harvester work with iceberg lettuce, we could also make it work with many other crops.""At the moment, harvesting is the only part of the lettuce life cycle that is done manually, and it's very physically demanding," said co-author Julia Cai, who worked on the computer vision components of the Vegebot while she was an undergraduate student in the lab of Dr Fumiya Iida.The Vegebot first identifies the 'target' crop within its field of vision, then determines whether a particular lettuce is healthy and ready to be harvested, and finally cuts the lettuce from the rest of the plant without crushing it so that it is 'supermarket ready'. "For a human, the entire process takes a couple of seconds, but it's a really challenging problem for a robot," said co-author Josie Hughes.The Vegebot has two main components: a computer vision system and a cutting system. The overhead camera on the Vegebot takes an image of the lettuce field and first identifies all the lettuces in the image, and then for each lettuce, classifies whether it should be harvested or not. A lettuce might be rejected because it's not yet mature, or it might have a disease that could spread to other lettuces in the harvest.The researchers developed and trained a machine learning algorithm on example images of lettuces. Once the Vegebot could recognise healthy lettuces in the lab, it was then trained in the field, in a variety of weather conditions, on thousands of real lettuces.A second camera on the Vegebot is positioned near the cutting blade, and helps ensure a smooth cut. The researchers were also able to adjust the pressure in the robot's gripping arm so that it held the lettuce firmly enough not to drop it, but not so firm as to crush it. The force of the grip can be adjusted for other crops."We wanted to develop approaches that weren't necessarily specific to iceberg lettuce, so that they can be used for other types of above-ground crops," said Iida, who leads the team behind the research.In future, robotic harvesters could help address problems with labour shortages in agriculture, and could also help reduce food waste. At the moment, each field is typically harvested once, and any unripe vegetables or fruits are discarded. However, a robotic harvester could be trained to pick only ripe vegetables, and since it could harvest around the clock, it could perform multiple passes on the same field, returning at a later date to harvest the vegetables that were unripe during previous passes."We're also collecting lots of data about lettuce, which could be used to improve efficiency, such as which fields have the highest yields," said Hughes. "We've still got to speed our Vegebot up to the point where it could compete with a human, but we think robots have lots of potential in agri-tech."
|
Agriculture & Food
| 2,019 |
July 8, 2019
|
https://www.sciencedaily.com/releases/2019/07/190708131155.htm
|
Plant nutrient detector breakthrough
|
Findings from La Trobe University-led research could lead to less fertiliser wastage, saving millions of dollars for Australian farmers.
|
The international research team has uncovered a protein that can sense vital phosphorus levels -- the 'fuel in the tank' -- in plants and then adjust growth and flowering in response.Published in the journal Lead author Dr Ricarda Jost, from the Department of Plant, Animal and Soil Sciences at La Trobe University said the environmental and economic benefits to farmers could be significant."In countries like Australia where soils are phosphorus poor, farmers are using large amounts of expensive, non-renewable phosphorus fertiliser, such as superphosphate or diammonium phosphate (DAP), much of which is not being taken up effectively by crops at the right time for growth," Dr Jost said."Our findings have shown that a protein called SPX4 senses the nutrient status -- the 'amount of fuel in the tank' of a crop -- and alters gene regulation to either switch off or turn on phosphorus acquisition, and to alter growth and flowering time."Using For the first time, the SPX4 protein was observed to have both a negative and a positive regulatory effect on phosphorus take-up and resulting plant growth."The protein senses when the plant has taken in enough phosphorus and tells the roots to stop taking it up," Dr Jost said. "If the fuel pump is turned off too early, this can limit plant growth."On the other hand, SPX4 seems to have a 'moonlighting' activity and can activate beneficial processes of crop development such as initiation of flowering and seed production."This greater understanding of how SPX4 operates could lead to a more precise identification of the genes it regulates, and an opportunity to control the protein's activity using genetic intervention -- switching on the positive and switching off the negative responses.La Trobe agronomist Dr James Hunt said the research findings sit well with the necessity for Australian farmers' to be as efficient as possible with costly fertiliser inputs."In our no-till cropping systems, phosphorus gets stratified in the top layers of soil. When this layer gets dry, crops cannot access these reserves and enter what we a call a phosphorus drought," Dr Hunt said."The phosphorus is there, but crops can't access it in the dry soil. If we could manipulate crop species to take up more phosphorus when the top soil is wet, we'd be putting more fuel in the tank for later crop growth when the top soil dries out."The research team will now be investigating in more detail how SPX4 interacts with gene regulators around plant development and controlling flowering time.The research was published in
|
Agriculture & Food
| 2,019 |
July 3, 2019
|
https://www.sciencedaily.com/releases/2019/07/190703121356.htm
|
How to sell labriculture: Less lab, more culture
|
In the near future, we will be able to mass-produce meat directly from animal cells.
|
This cultured meat could change the world -- or it could falter like GM 'frankenfoods'.Writing in "Cultured meat has the potential to reduce the ethical, environmental, and public health burdens associated with conventional livestock farming," says lead author Christopher Bryant of the University of Bath.In a free market, this potential can only be realized through consumer demand."Surveys show hesitancy towards cultured meat centers around its perceived 'unnaturalness', which can lead to concerns about food safety," explains Bryant.These echo consumer concerns about the last food technology breakthrough of this scale: GM crops."Extensive research has shown that media coverage of GM foods had a significant negative impact on public perceptions of, and behaviour towards, the technology."Just as 'climate change' took the heat off global warming, GMOs were reanimated as 'frankenfoods'. In the public imagination, will cultured meat ever truly leave the lab?"As most people have so far heard little or nothing of cultured meat," argues Bryant, "this is a crucial time to assess how the framing of this innovation can impact consumer perceptions."With co-author Dr. Courtney Dillard of Portland State University, Bryant assessed how framing cultured meat as (a) an innovation which benefits society, (b) a high-tech development, or (c) as very similar to conventional meat affected attitudes and behavioral intentions.Their sample of 480 US adults was broadly representative of the country as a whole in terms of age, gender, geographic distribution and diet (88% were meat eaters)."We found that those who encounter cultured meat through the 'high tech' frame have significantly more negative attitudes towards the concept, and are much less willing to consume it," reports Bryant.For example, the 'high-tech' framing group were the least likely to consider cultured meat safe, healthy or environmentally friendly. They rated themselves on average 14% less likely to try cultured meat, compared to the 'societal benefits' or 'same as meat' groups.Even before the frames were presented, the most common word associations to cultured meat across all 480 participants were "artificial" and "science.""Worryingly, cultured meat as a 'high-tech' development has been a very dominant frame in early media coverage, which frequently features 'science themed' photos such as meat in a petri dish in a lab. This may be causing consumers to develop more negative attitudes towards cultured meat than they otherwise might."The results sit well with findings from other cultured meat researchers."We'd love to get away from the 'lab-grown' label," says Tufts University researcher Natalie Rubio, who recently introduced an astounded world to cultured insect meat. "When cultured meat is ready to go, it won't be produced in a lab at all but in a food processing plant just like existing meat alternatives and other foods."The Good Food Institute in particular has demonstrated that consumers are much more likely to find 'clean meat' appealing than more technical terms like 'cultured meat' and 'cell-based meat'."Our suggestion to news media and startups is to normalize not only the name but the whole concept of clean meat -- which as the same taste, nutrition and basic building blocks as conventionally farmed meat. Hopefully, the texture and price will soon match too."Journalists can look down under for inspiration, says Bryant."This 'naturalness' has already been identified as a key focus in Australian media coverage of clean meat, in contrast with US and European counterparts."
|
Agriculture & Food
| 2,019 |
July 3, 2019
|
https://www.sciencedaily.com/releases/2019/07/190703121405.htm
|
Maize-centric diet may have contributed to ancient Maya collapse
|
The question of how to best adapt to extreme climate is a critical issue facing modern societies worldwide. In "The Role of Diet in Resilience and Vulnerability to Climate Change among Early Agricultural Communities in the Maya Lowlands," published in
|
"Population expansion and anthropogenic environment degradation from agricultural intensification, coupled with socially conditioned food preferences, resulted in a less flexible and less resilient system," Ebert writes. "Understanding the factors promoting resilience in the past can help mitigate the potential for similar sudden and dramatic shifts in our increasingly interconnected modern world."The study was conducted using the remains of 50 human burials from the ancient Maya community of Cahal Pech, Belize. Using AMS radiocarbon dating, Ebert and collaborators determined the age of the human burials found at Cahal Pech, both from the site core and surrounding settlements. These burials dated as early as the Middle Preclassic Period, between 735-400 B.C., and as late as the Terminal Classic, between approximately 800-850 A.D.At the Human Paleoecology and Isotope Geochemistry Laboratory at Penn State University, Ebert measured stable carbon and nitrogen isotope values of the bone collagen in the burials to determine characteristics of individual diets and how they changed through time. Of particular interest was the increasing proportion of C4 plants in the diet, which includes the Maya staple crop maize.For the burials dating to the Preclassic and Early Classic periods, representing the early inhabitants of the Cahal Pech, Ebert's results suggest that both elites and commoners had a diverse diet that, in addition to maize, included wild plants and animals procured through hunting. Ebert suggests that this diversity of food provided a buffer when a multi-century drought impacted the May lowlands between 300-100 B.C. "The resilience of complex social systems at Cahal Pech from the Preclassic through Early Classic was dependent in part upon a broad subsistence strategy that helped to absorb shocks to maize-based food production in the context of drought," Ebert writes.Things took a turn at during the Terminal Classic period, between 750 and 900 A.D., when growing social hierarchies and population expansion led to the intensifying of agricultural production and increasing reliance on maize. During this time frame, Ebert found that humans from surrounding settlements at Cahal Pech had different carbon values than the site's center, where the elite class lived. "Our results show a pattern of highly restricted stable nitrogen and carbon isotopes for elite individuals in the Late and Terminal Classic, which corresponds to a hyper-specialized maize-based diet that persisted through the final abandonment of the site," Ebert writes. Elite demands on the local population for increased maize production, and a preference for this drought-intolerant crop, was likely a factor that contributed to the failure of the Cahal Pech socio-political system in the face of another severe drought at the end of the Terminal Classic Period."The study speaks to the importance of diet in the resilience and decline of ancient societies and contributes to our understanding of vulnerability to climate change among modern traditional farming communities as well as industrialized nations," Ebert writes.
|
Agriculture & Food
| 2,019 |
July 2, 2019
|
https://www.sciencedaily.com/releases/2019/07/190702184601.htm
|
Can we feed 11 billion people while preventing the spread of infectious disease?
|
Within the next 80 years, the world's population is expected to top 11 billion, creating a rise in global food demand -- and presenting an unavoidable challenge to food production and distribution.
|
But a new article published in The article, "Emerging human infectious disease and the links to global food production," is the first to draw connections between future population growth, agricultural development and infectious disease."If we start exploring how increasing population and agriculture will affect human diseases, we can prepare for and mitigate these effects," said Jason Rohr, the Ludmilla F., Stephen J. and Robert T. Galla College Professor of Biological Sciences at the University of Notre Dame. "We need to anticipate some of the problems that may arise from an explosion of human population in the developing world."According to the article, the fastest area of population growth expected by the year 2100 will occur in the developing world where disease control, surveillance and access to health care already face significant challenges. Currently, some estimates suggest that infectious disease accounts for 75 percent of deaths in developing countries in tropical regions. Each year in the United States, an estimated 48 million people suffer from foodborne infections, and foodborne illnesses have been linked to imported food from developing countries -- where sanitation and food safety is lacking or poorly enforced. Of that number, 128,000 are hospitalized and approximately 3,000 people each year die from foodborne infection.As the world's population grows, the state of rural economies, use of agrochemicals and exploitation of natural resources, among other factors, are poised to further contribute to infectious disease outbreaks. "There are many modern examples where high human contact with farm animals or wild game is a likely cause of new human diseases that have become global pandemics," such as avian and swine flu, and mad cow disease, Rohr said.Rohr, who also works as part of Notre Dame's Environmental Change Initiative and the Eck Institute for Global Health, studies human schistosomiasis, a worm infection transmitted from snails to humans in many tropical and subtropical parts of the world.Through that research, he has seen firsthand how farming practices can affect disease because the snails thrive in waters with algae that grow prolifically in areas of agricultural runoff containing fertilizer. The primary predators of snails are prawns that migrate to estuaries to breed, but these estuaries often become unreachable because of dams installed to facilitate the irrigation of cropland."There is the perfect storm with schistosomiasis: Agriculture has decimated snail predators, irrigation ditches provide more snail habitat, and fertilizer use causes the proliferation of snail food," he noted. "Agriculture is important for nutrition that can be crucial for combating disease, but the right balance needs to be struck."Rohr and collaborators offer several potential solutions to various challenges, such as improving hygiene to combat the overuse of antibiotics to promote the growth of farm animals. They also suggest that farmers add genetic variability to their crops and animals to reduce epidemics caused in part by monocultures and too many closely related animals living in close quarters.Other solutions include enhancing education and health literacy, which has been documented as a major factor in reducing infections. The researchers also suggest investing in predictive mathematical models that integrate associations between agricultural practices and infectious diseases. These models could forecast risk across spatial scales to facilitate targeting preventive and mitigating measures.Rohr conducted a portion of his research as a member of the faculty at University of South Florida. Coauthors include Christopher B. Barrett of Cornell University; David J. Civitello of Emory University; Meggan E. Craft and David Tilman of the University of Minnesota; Bryan Delius and Karena H. Nguyen of the University of South Florida; Giulio A. DeLeo and Susanne H. Sokolow of Stanford University; Peter J. Hudson of Pennsylvania State University; Nicolas Jouanard and Gilles Riveau of Espoir pou la Santé, Senegal; Richard S. Ostfeld of the Cary Institute of Ecosystem Studies; and Justin V. Remais of the University of California, Berkeley.The research was funded by the National Science Foundation, National Institutes of Health, the U.S. Department of Agriculture, U.S. Environmental Protection Agency and the Bill and Melinda Gates Foundation, as well as grants from the University of California, University of Minnesota and the Stanford Global Development and Poverty Initiative.
|
Agriculture & Food
| 2,019 |
July 2, 2019
|
https://www.sciencedaily.com/releases/2019/07/190702112724.htm
|
Scientists discover processes to lower methane emissions from animals
|
University of Otago scientists are part of an international research collaboration which has made an important discovery in the quest to lower global agricultural methane emissions.
|
Professor Greg Cook, Dr Sergio Morales, Dr Xochitl Morgan, Rowena Rushton-Green and PhD student Cecilia Wang, all from the Department of Microbiology and Immunology, are members of the Global Research Alliance on Agricultural Greenhouse Gases that has identified new processes that control methane production in the stomach of sheep and similar animals like cattle and deer.Specifically, they determined the microbes and enzymes that control supply of hydrogen, the main energy source for methane producing microbes (methanogens).Professor Cook explains the discovery is important because methane emissions from animals account for about a third of New Zealand's emissions."Much of our work to date has focused on the development of small molecule inhibitors and vaccines to specifically target the production of methane by methanogens."This new work provides an alternative strategy where we can now begin to target the supply of hydrogen to methanogens as a new way of reducing animal methane emissions."While the breakthrough research was recently published in scientific journal International Society for Microbial Ecology Journal, Professor Cook says both he and Dr Morales have been working since 2012 with the Ministry for Primary Industries in support of the Global Research Alliance on a number of programmes to control greenhouse gas emissions.The international collaboration also involved researchers from AgResearch (New Zealand) and the Universities of Monash (Australia), Illinois (USA) and Hokkaido (Japan). Former Otago PhD student, now Associate Professor of Monash University's School of Biological Sciences, Chris Greening, led the study.Dr Morales says previous research had already shown that microbes play an important part in controlling methane levels. Now for the first time researchers understand why.The researchers studied two types of sheep -- those producing high amounts of methane and those producing less. They found the most active hydrogen-consuming microbes differed between the sheep. Importantly, in the low methane emitting sheep hydrogen consuming bacteria dominated, which did not produce methane.Their findings lay the foundation for strategies to reduce methane emissions by controlling hydrogen supply. One strategy is to introduce feed supplements that encourage non-methane producers to outcompete methanogens."Controlling the supply of hydrogen to the methanogens will lead to reduced methane emissions and allow us to divert the hydrogen towards other microbes that we know do not make methane," Dr Morales explains.
|
Agriculture & Food
| 2,019 |
July 1, 2019
|
https://www.sciencedaily.com/releases/2019/07/190701163835.htm
|
'Planting green' cover-crop strategy may help farmers deal with wet springs
|
Allowing cover crops to grow two weeks longer in the spring and planting corn and soybean crops into them before termination is a strategy that may help no-till farmers deal with wet springs, according to Penn State researchers.
|
The approach -- known as planting green -- could help no-till farmers counter a range of problems they must deal with during wet springs like the ones that have occurred this year and last year. These problems include soil erosion, nutrient losses, soils holding too much moisture and causing a delay in the planting of main crops, and main-crop damage from slugs."With climate change bringing the Northeast more extreme precipitation events and an increase in total precipitation, no-till farmers especially need a way of dealing with wet springs," said Heather Karsten, associate professor of crop production ecology, whose research group in the College of Agricultural Sciences conducted a three-year study of planting green. "We wanted to see if farmers could get more out of their cover crops by letting them grow longer in the spring."As cover crops continue to grow, they draw moisture from the soil, creating desired drier conditions in wet springs for planting corn and soybeans. With planting green, after those main crops are planted into the cover crops, the cover crops are typically terminated by farmers with an herbicide. The decomposing cover crop residues then preserve soil moisture for the corn and soybean crops through the growing season.The study took place at five sites over three years -- on three cooperating Pennsylvania farms that plant no-till in Centre, Clinton and Lancaster counties; at Penn State's Russell E. Larson Agricultural Research Center in Centre County; and at the University's Southeast Agricultural Research and Extension Center in Lancaster County.At each location, researchers compared the results of planting green to the traditional practice of terminating cover crops 10 days to two weeks before planting the main crops of corn and soybeans.Cover crops included in the study were primarily rye and triticale, as well as a mixture of triticale, Austrian winter pea, hairy vetch and radish in one location.Findings of the research, recently published online today in Reed noted that planting green appeared to benefit soybean crops more than corn.Planting green increased cover crop biomass by 94 percent in corn and by 94 to 181 percent in soybean.However, because planting green results in more cover crop residues acting as mulch on the surface, it also cooled soils from 1.3 to 4.3 degrees Fahrenheit at planting.At several of the sites during the study years, main-crop plant populations were reduced when planted green, possibly due to the cooler temperatures slowing crop emergence and nutrient cycling, and/or from cover crop residue interference with the planter. In corn, in a few cases, crop damage by slugs was also increased when corn was planted green.No-till farmers struggle with slugs damaging corn and soybean seeds and seedlings because no-till doesn't disturb the soil and kill slugs or bury their eggs the way tillage does."No-till with cover crop residues also provides habitat for some crop pests and keeps the soil moist -- so no-till cover crop systems tend to be great slug habitat," Karsten said."We had hoped that letting cover crops grow longer in the spring would supply alternative forage for the slugs, as well as habitat for slug predators such as beetles -- and these factors would reduce slug damage of the main crop seedlings. But we did not see a consistent reduction in slug damage on main crops as we expected."When researchers compared crop-yield stability between the two cover crop termination times across the multiple locations and years, corn yield was less stable and reduced by planting green in high-yielding environments; however, soybean yield was not influenced by planting green."We concluded that corn was more vulnerable to yield losses from conditions created by planting green than soybeans, " Reed said. "Since soybean yield was stable across study locations, and not affected by cover crop termination date, we suggest that growers who want to extend cover crop benefits and avoid the risk of crop-yield reduction from planting green should consider trying it first with soybean."
|
Agriculture & Food
| 2,019 |
July 1, 2019
|
https://www.sciencedaily.com/releases/2019/07/190701144511.htm
|
Environmentally friendly control of common disease infecting fish and amphibians
|
Aquatic organisms in marine systems and freshwaters are threatened by fungal and fungal-like diseases globally. These pathogens are especially dreaded in aquaculture. But they also pose a threat to biodiversity of amphibians. There are few approved chemical means for combating these pathogens, and many have unwanted side-effects. Scientists at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) now propose alternative biological concepts to control fungal disease in a more environmentally friendly way.
|
Some fungal and fungal-like diseases produce small infectious stages -- zoospores -- that swim in water to look for new hosts. They can infest fish, amphibians but also algae and seaweeds that are produced for human consumption. "The damage caused by these diseases is considerable. Few chemicals are approved for prophylaxis, but are expensive, harmful to the environment and often ineffective on the long run -- which makes proper application very difficult, especially when used in species protection," says Dr. Thijs Frenken, lead author of the study, describing the problem.80 million tons of global fish productions come from aquaculture, and its share in human protein diet is expected to increase. Diseases are the largest cause of economic losses in aquaculture. At least ten percent of all hatched salmon in the aquaculture industry succumb to zoosporic diseases. On Scottish salmon farms alone, for example, infections with this fungal disease lead to production losses of at least 6.5 million US dollars per year. Efficient and sustainable ways of controlling fish diseases are therefore paramount to the future success (and economic viability) of the aquaculture industry. "We have to go back to the basics and start applying our ecological understanding of these organisms to limit spread of infections," specifies Frenken.The researchers propose 7 biological concepts for the protection of aquatic organisms against zoosporic diseases, which may be less harmful and more sustainable than chemical methods:2. Increase the diversity of host species: The so-called monoculture effect applies -- genetically homogeneous populations are more susceptible to infectious agents. Making host populations/communities more diverse can limit spread of infections.3. Vaccination and immunisation: Vaccinating fish against viral or bacterial diseases is a common practice in aquaculture. No vaccines against fungal-like diseases currently exist, but this could be a promising avenue.4. Stimulate defense and production of anti-fungal peptides by the host: When parasitic pathogens enter the host, host cells die and peptides are released. These signalling substances induce an increased immune defence in the neighbouring cells.5. Probiotics: They can inhibit growth of parasitic zoospores, and also can prevent attachment of zoospores to the host by forming surface-active substances. Probiotics have already been successfully tested in fish as a treatment for zoosporic infections.6. Hyperparasitism: Introduce another parasite that infects (and eliminates) the target parasite.7. Use "parasite eaters": Eating parasites is very common practice in nature. Other microscopic organisms in the water (zooplankton), for example, can "graze" on parasitic fungi."The constantly changing environmental conditions have a great influence on the parasite-host interaction. These dynamics must also be incorporated into the planning of protection and therapy concepts. We hope that our work will stimulate the further development of alternative biological control strategies. Much more work is needed before we can safely implement these methods into natural habitats without incurring unforeseen risks," emphasizes IGB researcher and head of the study, Prof. Dr. Justyna Wolinska.
|
Agriculture & Food
| 2,019 |
July 1, 2019
|
https://www.sciencedaily.com/releases/2019/07/190701144338.htm
|
Building up an appetite for a new kind of grub
|
Edible insects could be a key ingredient to avoiding a global food crisis, according to a new report, but there are significant barriers to overcome before they are part of the mainstream.
|
The rapidly changing climate and an expanding global population are serious risks for worldwide food security. Edible insects have a high nutritional value and significantly lower carbon footprint compared to meat production and are a viable option as a sustainable source of protein. Despite this, edible insect cultivation remains rare in Western countries, where eating insects is still considered unusual.In a new study, researchers from the University of Leeds and University of Veracruz in Mexico have reviewed current insect farming methods, processing technologies and commercialisation techniques, as well as current perceptions towards entomophagy -- the practice of eating insects.Their report is published in the journal Study author Dr Alan-Javier Hernández-Álvarez from the School of Food Science and Nutrition at Leeds said: "Edible insects are fascinating. Although humans have eaten insects throughout history, and approximately two billion people around the globe regularly eat them today, research on the subject is relatively new."Edible insects could be the solution to the problem of how to meet the growing global demand for food in a sustainable way."The 'ick factor' remains one of the biggest barriers to edible insects becoming the norm. Eating behaviour is shaped largely during early childhood and in Western countries, eating insects, especially in whole and recognisable forms, remains something seen mostly on TV shows."In some European countries consumers, particularly young adults, have shown interest in new food products that use insects in un-recognisable form, such as flour or powder used in cookies or energy drinks. Developing efficient large-scale processing technologies that can develop insects powders could go a long way to helping introduce insects as a common source of protein and nutrients."Study author Dr Guiomar Melgar-Lalanne from the University of Veracruz said: "In Western countries it is the younger generation that show more willingness to try new food products, including edible insects. The 'foodies boom' and the rise of veganism and flexitarians have opened the door to alternative food sources."However, in some countries where insects have been part of a culinary tradition, such as Mexico, Nigeria and Botswana, negative perceptions of eating insects have taken root. In these countries the younger population is rejecting insects as a food source, associating it with poverty and a provincial mind set."In Mexico for example, where insect markets are increasingly popular among tourists, self-consumption, harvesting and farming are declining in rural areas. Despite the growing demand for edible insects in urban areas, harvesting and indoor farming is limited because farmers associate insects with poverty and do not see it as a potential source of income."Promoting insects as an environmentally sustainable protein source appeals to the current attitudes in the younger generation. Another successful strategy involves serving insects as snacks between meals, which would increase inclusion of insects in daily diets. These types of snacks are increasing in popularity in the global market."But if edible insects are to become a common food source current farming techniques and technologies could struggle with the demand and need to be expanded."Compared to meat production, insect farming uses much smaller amounts of land, water and feed, and it is possible to cultivate them in urban areas. Insect farming also produces far fewer greenhouse gases.However, more development is needed in large-scale insect farming. Increasing demand could create a bottleneck in the production of more edible insects in an economically efficient, safe and sustainable matter. The lack of availability creates accessibility issues and therefore reduces opportunities for increasing trade. There is significant need for a technological leap from wild harvesting to indoor farming.Improvements to edible insect farming and processing techniques could also open the door for increasing the use of insects for other purposes. Chitin extracted from certain insect exoskeletons has the potential for use in food preservation. It also has a number of industrial applications such as surgical thread and as a binder used in glue.Dr Hernández-Álvarez added: "Food is only the tip of the iceberg for insects' sustainable potential."Refining extraction technologies could make insects a feasible and sustainable option for replacing some currently available functional ingredients. These aspects should be a focus of future research and technological development."
|
Agriculture & Food
| 2,019 |
June 28, 2019
|
https://www.sciencedaily.com/releases/2019/06/190628120521.htm
|
Embracing bioinformatics in gene banks
|
The preservation of plant biodiversity is the task of the roughly 1,750 gene banks which are distributed around the world. So far, they store plant samples, and sometimes additional phenotypic or genetic information, of around 7,4 million accessions of plant species in total. It is expected that with the facilitated access to improved, quicker and cheaper sequencing and other omics technologies, the number of well-characterised accessions and the amount of detailed information that needs to be stored along with the biological material will be growing rapidly and continuously. A team of scientists from the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) in Gatersleben has now looked ahead into the upcoming challenges and possibilities of the future of gene banks by publishing a perspective paper in
|
In the early-to-mid twentieth century, it became increasingly apparent that crop landraces were slowly being replaced by modern crop varieties and were in danger of disappearing. In order to prevent loss of genetic diversity and biodiversity, the first gene banks were established, with the mission to preserve these plant genetic resources. Nowadays, gene banks function as biorepositories and safeguards of plant biodiversity but most importantly as libraries which turn the genetic plant information and plant material into a freely accessible but nonetheless valuable resource. As such, scientists, plant breeders or even anybody from around the world can request and use the data stored within more than 1,750 gene banks around the world for research or plant breeding purposes.The Gene Bank of the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) in Gatersleben currently holds one of the world's most comprehensive collections of crop plants and their wild relatives, collating a total of 151,002 accessions from 2,933 species and 776 genera. The majority of the plant germplasm samples are stored as dry seed at -18°C, whilst accessions which are propagated vegetatively are permanently cultivated in the field (ex situ) or preserved in liquid Nitrogen at -196°C. The online portal of the IPK gene bank allows users to view and sift through the stored plant accessions and their corresponding "passport data," as well as to request plant material on a non-commercial scale. A new perspective paper authored by Dr. Martin Mascher and colleagues of the IPK now examines the current and upcoming challenges for gene banks but also the opportunities for their further advancement.The scientists identified three major challenges for gene banks which will need attention. Two are caused by the basic demands of managing tens of thousands of seed lots, namely the tracking of the identity of accessions, and the need to avoid unnecessary duplications within and between gene banks. The third challenge is that of maintaining the genetic integrity of accessions, due to the inherent drawbacks of using ex situ conservation, such as differential survival, drift and genetic erosion in storage and regeneration.However, the authors suggest that a stronger genomic-driven approach towards gene banks might help when taking on these challenges. For example, traditionally, the "passport data" of the gene bank material describe the taxonomy and provenance of accessions. By adding single-nucleotide polymorphisms (SNPs) as defining characteristics of an accession, this genotypic information could serve as molecular passport data to complement and correct traditional passport records, as well as assist with the cleansing and prevention of duplicates and improve the quality and integrity of the collections.By implementing the shift towards bioinformatics and big data analytics in plant sciences, traditional gene banks, which focus on the preservation of germplasm collections, will be able to transform into bio-digital resource centres, which combine the storage and valorisation of plant materials with their genomic and molecular characterisation.Current funding scenarios of gene banks do not yet allow for the systematic generating of molecular passport data for each submitted plant sample at gene banks. However, first steps into the direction of high-throughput genotyping of entire collections have already been taken. This was previously showcased by an international research consortium led by the IPK, which characterised a world collection of more than 22,000 barley varieties on a molecular level through genotyping-by-sequencing. Some of the authors of the perspective paper had also been involved in this case-study and had contributed to the creation of the web-information-portal BRIDGE as a result. BRIDGE, short for "Biodiversity informatics to bridge the gap from genome information to educated utilization of genetic diversity hosted in gene banks," is a data storage for the attained genomic barley information which links to the phenotypic information collated at the IPK hosted Federal Ex situ Gene Bank for Agricultural and Horticultural Crop Species.Whilst BRIDGE is already paving the way towards evolving the Gaterslebener Gene Bank into a "one stop shop for facilitated and informed utilisation of crop plant biodiversity," international collaborations, such as the organisation DivSeek, are building the international framework for enabling gene banks, plant breeders and researchers globally to more efficiently process and mobilise plant genetic diversity, thus starting to bridge the gaps between bioinformaticians, geneticists and gene bank curators. Hence, a worldwide network of bio-digital resource centres, sharing data freely and thus help fostering research progress in plant science and plant breeding may become a reality in the near future.
|
Agriculture & Food
| 2,019 |
June 28, 2019
|
https://www.sciencedaily.com/releases/2019/06/190628120453.htm
|
Global agriculture: Impending threats to biodiversity
|
A new study compares the effects of expansion vs. intensification of cropland use on global agricultural markets and biodiversity, and finds that the expansion strategy poses a particularly serious threat to biodiversity in the tropics.
|
Global agricultural production must be further increased in the coming years in order to meet rising demand and changing patterns of consumption. This will require either intensification of cropland use or an expansion of farmland. Researchers based at Ludwig-Maximiians-Universitaet (LMU) in Munich, at the Kiel Institute for the World Economy, at the Helmholtz Center for Environmental Research (Leipzig) and at Palacký University in Olomouc (Czech Republic) have now evaluated the trade-offs between food security and the preservation of biodiversity associated with both strategies in the context of global agricultural markets. The study appears in the journal "Agriculture is one of the major drivers of biodiversity loss worldwide, and increases in production are almost always achieved at the expense of biodiversity. But whether and where production rises due to intensification or expansion of cropland does make a difference," says Dr. Florian Zabel of the Department of Geography and Remote Sensing at LMU.The researchers involved in the interdisciplinary collaboration set out to identify those areas in which it would be profitable, under projected climatic and socioeconomic conditions for the next decade, to increase agricultural production by intensifying or expanding the use of land for farming. They then asked what effects each of these strategies would have on biodiversity and global agricultural markets."Our results show that, for a given rise in food production, the impact of cropland expansion on biodiversity is many times greater than that of the intensification scenario. This is because expansion can be expected to occur in those regions with the highest existing levels of biodiversity, mainly in Central and South America," says Dr. Tomáš Václavík, who is in the Department of Ecology and Environmental Sciences at Palacký University in Olomouc. Near-term intensification of agriculture on existing cropland, on the other hand, primarily presents a threat to biodiversity in Sub-Saharan Africa.However, while biodiversity is set at risk in those regions in which more food is produced, the study suggests that all parts of the world -- including those in which the local rise is modest -- will profit from the fall in food prices that ensues as a result of the overall growth in global production. "This result has potentially critical implications, because it suggests that, while all regions -- including North America and the EU -- will profit from sinking food prices, the threat to biodiversity is greatest in developing countries in the tropical regions," says Dr. Ruth Delzeit of the Kiel Institute for the World Economy. The effects of intensification and expansion are also predicted to play out differently within these regions. Intensification promises the highest gains in food security in some regions of the tropics, principally India and Sub-Saharan Africa. In contrast, the study sees inhabitants of Latin American countries such as Brazil as the primary beneficiaries of lower food prices brought about by cropland expansion. However, in this region, the expansion strategy presents an especially serious threat to biodiversity.In addition, the study shows that most existing nature reserves are not located in those regions of high species diversity that were identified as likely targets of cropland expansion. "Most of the areas with high levels of biodiversity that are suitable for agricultural expansion and intensification in the coming years are not currently protected. We therefore recommend to develop global mechanisms which recognize land as a limited resource. Measures should be implemented to protect biodiversity in landscapes that are in use rather than focusing solely on protection sites," says Professor Ralf Seppelt of the Helmholtz Center for Environmental Research in Leipzig. This is the only practicable way to achieve a balance between the conservation of existing biodiversity and the need to increase global agricultural production.
|
Agriculture & Food
| 2,019 |
June 27, 2019
|
https://www.sciencedaily.com/releases/2019/06/190627143941.htm
|
Immediate, science-based community action can mitigate insect decline
|
This year, German environmentalists collected 1.75 million signatures for a 'save the bees' law requiring an immediate transition toward organic farming. But to create healthy ecosystems worldwide, people in communities across the globe will need to take similar action based on empathy for insects -- and not only for bees and butterflies -- according to entomologists Yves Basset from the Smith-sonian Tropical Research Institute and Greg Lamarre from the University of South Bohemia, writing in
|
"What is new is the clear call to present our research in ways that everyone can understand it be-cause communities need specific information to justify local political initiatives," said Basset, who coor-dinates a project to monitor insects in nine countries as part of the ForestGEO research program at the Smithsonian."It takes specific legislation to preserve the amazing variety of insects in the world and the critical services they provide by stopping the destruction of natural habitats, limiting road building in parks and reserves and producing food without the use of pesticides," Basset said, "Conserving insects is not the same as conserving big mammals or rare frogs. You can't keep millions of insects in a zoo."A recent article in But there are still huge gaps in information about how different species of insects are doing, es-pecially in the tropics. Even in temperate areas, where insect declines are reasonably well documented, some pest species are on the rise."It is next to useless to weigh insects collected in an area and say that insect communities are in-creasing or declining." Basset said. "We need much more specific information. That is expensive and we are also hindered by the effort that it takes just to identify the species, especially in the tropics. What we are doing now is to group insects by their main function: pollinators, decomposers, predators on other insect species, and then to determine how each group is doing in a specific area of the world."For example, some of the top predators of insects are other insects. When we eliminate these spe-cies it may result in a population explosion of smaller insects, some of which carry dangerous diseases: more insect biomass does not necessarily mean that we are protecting insect diversity.Basset published a paper in 2017 showing that the response of butterflies to environmental change was very different from the response of termites. This illustrates the need to study insects as dis-tinct entities, each with different ecological requirements and exposed to different threats.When people refer to global insect declines, there is very limited information from the tropics where the majority of all insect species live. And much of the data is from reserves far from pesticide use and habitat destruction. The article calls for more research on tropical insects."Barro Colorado Island, the Smithsonian research station in Panama's tropical forest, is only about 15km2 and there are more than 600 butterfly species," Basset said. "We can only tell you if about 100 of them are declining. For the rest, we simply have no data. In the tropics, insects outnumber mam-mals 300 to one. High-ranking scientific journals would publish a graph of jaguar decline, but not 300 graphs showing declines of obscure insect species."Basset points out the window at a patch of trees in the courtyard of STRI headquarters in Pana-ma. "There are probably thousands of species in that little grove of trees. I'm not kidding.""The creation of sustainable systems for environmental protection, transportation and agriculture will depend on biologically literate, empathetic people who join together to create knowledge-based legis-lation as they did in Germany," Basset said.
|
Agriculture & Food
| 2,019 |
June 27, 2019
|
https://www.sciencedaily.com/releases/2019/06/190627143115.htm
|
The world needs a global system to detect and halt the spread of emerging crop diseases
|
More than 20 percent of the five staple crops that provide half the globe's caloric intake are lost to pests each year. Climate change and global trade drive the spread, emergence, and re-emergence of crop disease, and containment action is often inefficient, especially in low-income countries. A Global Surveillance System (GSS) to strengthen and interconnect crop biosecurity systems could go a long way to improving global food security, argues a team of experts in the June 28 issue of
|
"As part of efforts to satisfy global demand for food -- which could mean increasing agricultural production by as much as 70 percent by 2050 -- we need a GSS to reduce food lost to pests," said Mónica Carvajal, a researcher at the International Center for Tropical Agriculture (CIAT) and lead author. "A lot of collaboration and discussion is needed to rapidly take action and avoid outbreaks that could negatively impact food security and trade."Carvajal and colleagues hope the GSS framework they propose gains traction in 2020, which was designated International Year of Plant Health by the United Nations. The system would prioritize six major food crops -- maize, potato, cassava, rice, beans, and wheat -- as well as other important food and cash crops that are traded across borders. The GSS proposal is the result of a scientific meeting convened by CIAT and held in 2018 at the Rockefeller Foundation's Bellagio Center in Italy.In 2015, Cassava Mosaic Disease (CMD) was discovered in Cambodia but the findings were not reported until 2016. By 2018, the disease had spread to Thailand and Vietnam, and is now estimated to be present in 10 percent of the surfaces cultivated in the region, threatening millions of smallholders who cultivate cassava and generate US$4 billion in export revenue.This year, agricultural authorities from four countries -- Cambodia, Thailand, Vietnam, and Lao PDR -supported by research organizations including CIAT, published an emergency control plan for CMD in Southeast Asia.Carvajal, who studied the CMD outbreak after its initial report, says that a GSS would help expedite action for future outbreaks."The question I asked was why does it take so long to respond to crop diseases in some cases?" said Carvajal. "What is the limitation to responding faster from the outset?"The GSS proposal draws on lessons learned from the wheat blast outbreak that hit Bangladesh in 2016 and the bacterial outbreak of Xylella fastidiosa that started affecting olive trees in Europe in 2013. The proposal is from a multidisciplinary group of experts from academia, research centers, and funding organizations that work on issues related to plant health and human health.The GSS would focus on tightening networks "active surveillance" and "passive surveillance" personnel who are on the front lines of disease outbreaks. Active surveillance consists of laboratories at agriculture inspection stations, and customs and phytosanitary inspectors at borders and ports of entry. Despite their formal infrastructure, only an estimated 2-6 percent of cargo can be effectively screened.The second group includes loose networks of farmers, extension workers with national agricultural organizations, scientists and agronomists at research centers and universities, and specialists in agriculture industries."For this infrastructure to be effective, connections between first detectors and downstream responders must be enhanced and actions coordinated," said the authors. "But diagnostic capacity, information sharing, and communications protocols are lacking or weakly established in some regions, especially in low-income countries. Our reflection on many disease outbreaks is that whether in high-income countries or low-income countries, the passive surveillance infrastructure has the most in-field monitoring eyes but the least coordination from local to global."The GSS would tap into cutting-edge technology for rapid disease diagnostics and take advantage of communications networks, including social media, to rapidly share information. The system would have regional hubs and consist of five formal global networks. These would include a diagnostic laboratory network, a risk assessment network, a data management network, an operational management network, and a communications network."Our team realized that there is a big issue with communication, even when we speak the same language and use the same technologies," said Carvajal. "One of the most relevant components is the communications network." The GSS team hopes to contribute to future efforts on strengthening pest outbreak response systems within the International Plant Protection Convention's (IPPC) 2020-2030 Strategic Framework."We encourage the annual G20 Agriculture Ministers Meeting, the World Bank Group, and FAO, among others, to join efforts toward enhancing cooperation for a multi-year action plan for the proposed GSS to more effectively reduce the impact of crop diseases and increase global food security," the authors conclude.
|
Agriculture & Food
| 2,019 |
June 27, 2019
|
https://www.sciencedaily.com/releases/2019/06/190627134017.htm
|
Trees for water quality credits
|
The more naturally verdant an area is, the more likely it will contribute to the general health of the habitats and the organisms in and around it. Sometimes, though, tracing these qualities to specific benefits can be a challenge.
|
However, in a study published in the journal "While we have intuitively known that reforestation can be a very positive action, to date, determining how much bang for your buck you can get in terms of water quality has not been reliably quantified," said Keller, the study's lead author and a faculty member in the Bren School of Environmental Science & Management. "Here we present an approach for identifying areas where reforestation will be most effective for improving water quality, using a widely available USDA model and data sets that anyone can access."For this study, Keller and co-author Jessica Fox, from the Electric Power Research Institute (EPRI), focused on a section of America's bread basket -- the Ohio River Basin, more than a third of which is engaged in agriculture, and a water source for millions of people. Importantly, the entire basin, along with five other major river basins, drains into the Gulf of Mexico via the Lower Mississippi River Basin. Nutrients -- in particular, nitrogen and phosphorus -- transported via runoff mainly from farms and other agricultural operations all flow into the Gulf, creating a massive algae bloom and subsequent oxygen-free "dead zone" in the summer months that threatens or kills marine life within its boundaries.The National Oceanic and Atmospheric Administration has predicted that the dead zone this summer could encompass a 7,829-square-mile area, one of the largest Gulf of Mexico dead zones on record.According to the study, marginal croplands -- lands with low agricultural value due to conditions such as poor soil quality, inadequate water supply and slopes that render farming difficult -- when planted with trees could be used not only to store carbon, but also to substantially reduce the movement of nitrogen, phosphorus and sediments from land to streams and rivers."Trees retain soil and sediments almost completely, compared to open fields, and take up the available nitrogen and phosphorus, as well as store carbon," said Keller, whose primary expertise lies in water quality management at the watershed level and the fate and transport of pollutants in the environment. "Quantifying these effects can now be used to give tradable credits for improving water quality."Additionally, according to Keller, reforestation of marginal croplands also increases biodiversity, provides habitat and can be used economically by sustainably harvesting the timber -- all without sacrificing prime agricultural value. Ideal candidates for reforestation are croplands on hill slopes that have poor soil infiltration, yet are close to a receiving water body.The Ohio River Basin is also the location of the world's largest water quality trading program. Administered by EPRI, the Ohio River Basin Water Quality Trading Project is a market-based approach to achieving better water quality by issuing permits to discharging facilities and requiring them to meet nutrient limits. Facilities can earn credit for these permits by paying local farmers to employ practices such as reducing fertilizer use, preventing manure from washing into streams, or planting trees by streams to help reduce runoff. The nutrient reductions can be used as credits to help the facilities meet permit requirements.According to the study, approximately 10% of the current cropland in the Ohio River Basin region was identified as a high priority for reforestation."If this area was converted from marginal cropland to healthy forests, there would be the potential to avoid 60 million kilograms of nitrogen and two million kilograms of phosphorus from reaching the streams and rivers of the northern Ohio River Basin," Keller said. "That's on the order of a 12% decrease in total nitrogen, and a 5% decrease for total phosphorus for the entire basin, which drains to the Gulf of Mexico."While the results might differ for projects with varying local conditions, the potential for reducing nutrient loading demonstrated in the study, the ancillary benefits to the environment and economy, and the low impact to prime agricultural cropland together make this approach worth considering for managing water quality in waterways throughout the world, he said.
|
Agriculture & Food
| 2,019 |
June 26, 2019
|
https://www.sciencedaily.com/releases/2019/06/190626160339.htm
|
Honeybees infect wild bumblebees through shared flowers
|
Many species of wild bumblebees are in decline -- and new research shows that diseases spread by domestic honeybees may be a major culprit.
|
Several of the viruses associated with bumblebees' trouble are moving from managed bees in apiaries to nearby populations of wild bumblebees -- "and we show this spillover is likely occurring through flowers that both kinds of bees share," says Samantha Alger, a scientist at the University of Vermont who led the new research."Many wild pollinators are in trouble and this finding could help us protect bumblebees," she says. "This has implications for how we manage domestic bees and where we locate them."The first-of-its-kind study was published June 26 in the journal Around the globe, the importance of wild pollinators has been gaining attention as diseases and declines in managed honeybees threaten key crops. Less well understood is that many of the threats to honeybees (Apis mellifera) -- including land degradation, certain pesticides, and diseases -- also threaten native bees, such as the rusty patched bumblebee, recently listed under the Endangered Species Act; it has declined by nearly 90% but was once an excellent pollinator of cranberries, plums, apples and other agricultural plants.The research team -- three scientists from the University of Vermont and one from the University of Florida -- explored 19 sites across Vermont. They discovered that two well-know RNA viruses found in honeybees -- deformed wing virus and black queen cell virus -- were higher in bumblebees collected less than 300 meters from commercial beehives. The scientists also discovered that active infections of the deformed wing virus were higher near these commercial apiaries but no deformed wing virus was found in the bumblebees they collected where foraging honeybees and apiaries were absent.Most impressive, the team detected viruses on 19% of the flowers they sampled from sites near apiaries. "I thought this was going to be like looking for a needle in a haystack. What are the chances that you're going to pick a flower and find a bee virus on it?" says Alger. "Finding this many was surprising." In contrast, the scientists didn't detect any bee viruses on flowers sampled more than one kilometer from commercial beehives.The UVM scientists -- including Alger and co-author Alex Burnham, a doctoral student -- and other bee experts have for some years suspected that RNA viruses might move from honeybees to bumblebees through shared flowers. But -- with the exception of one small study in a single apiary -- the degree to which these viruses can be "horizontally transmitted," the scientists write, with flowers as the bridge, has not been examined until now.Taken together, these results strongly suggest that "viruses in managed honeybees are spilling over to wild bumblebee populations and that flowers are an important route," says Alison Brody, a professor in UVM's Department of Biology, and senior author on the new Alger -- an expert beekeeper and researcher in UVM's Department of Plant & Soil Science and Gund Institute for Environment -- is deeply concerned about the long-distance transport of large numbers of honeybees for commercial pollination. "Big operators put hives on flatbed trucks and move them to California to pollinate almonds and then onto Texas for another crop," she says -- carrying their diseases wherever they go. And between bouts of work on monoculture farm fields, commercial bees are often taken to more pristine natural habitats "to rest and recover, where there is diverse, better forage," says Alger."This research suggests that we might want to keep apiaries outside of areas where there are vulnerable pollinator species, like the rusty patched bumblebees," Alger says, "especially because we have so much more to learn about what these viruses are actually doing to bumblebees."Honeybees are an important part of modern agriculture, but "they're non-native. They're livestock animals," Alger says. "A huge misconception in the public is that honeybees serve as the iconic image for pollinator conservation. That's ridiculous. It's like making chickens the iconic image of bird conservation."
|
Agriculture & Food
| 2,019 |
June 26, 2019
|
https://www.sciencedaily.com/releases/2019/06/190626133718.htm
|
Undercounting of agroforestry skews climate change mitigation planning and reporting
|
Farmers incorporate trees into fields and pastures to earn cash from fruit or wood, increase fodder and shade for livestock, promote soil health or protect against wind or water erosion. In all cases, farmers contribute to climate change mitigation by increasing soil and biomass carbon sequestration.
|
But it appears they are a step ahead of the United Nations Framework Convention on Climate Change, the global organization that aims to stabilize our climate.In an article published today in the journal Scientists call for improved accounting and visibility, including through better data and satellite imagery, for agroforestry to support increases in food production and massive scaling of soil and biomass carbon sequestration.Just as farmers value trees on their farms, 40% of developing countries name agroforestry as a strategy for adapting to and mitigating climate change. In Africa, 71% of countries identify agroforestry as a critical climate strategy.However, research being released shows that just sixteen developing countries provided quantitative estimates that include the number or areal extent of trees outside forests. The gap between what is reported and what could be reported is immense: scientists have estimated that some type of agroforestry is practiced on 43% of all agricultural land -- over 1 billion hectares -- providing subsistence to more than 900 million people.Scientists recommend four steps to improve national and global accounting of agroforestry, with recognition that better measurement, reporting and verification of farm-scale, national, and global benefits of agroforestry are necessary to tap transformative support for large-scale agroforestry. In many cases, capacity building and use of existing data could improve accounting of agroforestry.Transparency of climate actions, including in agroforestry, is essential for long-term climate stability.
|
Agriculture & Food
| 2,019 |
June 26, 2019
|
https://www.sciencedaily.com/releases/2019/06/190626124954.htm
|
Managing the ups and downs of coffee production
|
National Council for Scientific and Technological Development, Empresa de Pesquisa Agropecuaria de Minas Gerais
|
Each day, more than 2 billion cups of coffee are consumed worldwide.Developing countries produce about 90% of the beans used to make all those lattes, espressos and mochas. That makes coffee a key source of revenue and livelihood for millions of people worldwide.But coffee plants have up-and-down yield patterns. Years with high yields are often followed by years with low yields and vice-versa. This alternating pattern of high and low yields is called the "biennial effect.""It's like physiological recovery," says Indalécio Cunha Vieira Júnior. "Coffee plants need to 'vegetate' for a year to produce well the following year." Cunha is a researcher at the Federal University of Lavras in Brazil.The biennial effect makes it challenging for coffee breeders to compare yields from different varieties of coffee. Without accurate measures of yield, breeders cannot know which varieties of coffee would be most useful for farmers to grow.In a new study, Cunha and colleagues outline a computational model that compensates for the biennial effect in coffee. This model reduces experimental error. It also increases the usefulness of data obtained from field trials. In turn, the model directly impacts the quality of coffee varieties supplied to farmers."Ultimately, our findings could reduce the cost and time to launch a new coffee variety into the market by half," says Cunha.The new model could also help farmers improve yields. "The model generates data on biennial growth at the level of individual coffee plants," says Cunha. Using information from the model, farmers could tailor cultivation strategies to individual plants. Effective management of growing conditions directly impacts harvest quality and yields.The study also yielded some unexpected results. Researchers discovered that the biennial effect in coffee doesn't follow a well-defined pattern, as previously thought."Many researchers assumed that all coffee plants in an area would have similar yield patterns," says Cunha. But, researchers found that some coffee plants can have reasonably stable yields across years. Other plants may have high yields for two years and reduced yields in the third."These findings will change how coffee breeding experiments are analyzed," says Cunha.The new model also allows researchers to determine why individual coffee plants may have high or low yields each year.Some coffee plants with high yields may belong to high-yielding varieties. However, the plants of high-yielding varieties may produce low yields during recovery years."Our model enables us to delve deeper into the biennial effect," says Cunha. "This could allow us to recommend the most productive varieties for farmers with higher accuracy and lower costs."Cunha and colleagues used a computer simulation to test the effectiveness of their model. "The simulation allowed us to confirm our findings on real data," says Cunha. It also helped researchers test conditions in which the model performed well and when it ran into difficulties.In general, "simulation results showed the model could effectively determine individual biennial stages," says Cunha. The new model was shown to be an improvement over older models.Cunha is now trying to incorporate more genetic information into the current model. This would allow researchers to study genetic control of the biennial effect. Understanding the genetic basis of the biennial effect could be very useful. For example, it might allow breeders to identify coffee varieties with more uniform yields across multiple years.Coffee isn't the only crop to show biennial effects. Apple trees, for example, also exhibit biennial effects. Findings from Cunha's work could also apply to these other crop varieties.This research was supported by the National Council for Scientific and Technological Development (CNPq)and Empresa de Pesquisa Agropecuária de Minas Gerais (EPAMIG).
|
Agriculture & Food
| 2,019 |
June 26, 2019
|
https://www.sciencedaily.com/releases/2019/06/190626005208.htm
|
Organic farming enhances honeybee colony performance
|
Bees are valuable to humans not only because they produce honey, but also because they pollinate wildflowers and food crops. They exclusively eat nectar and pollen. So in areas where intensive agriculture is practised, they suffer from the thin supply of flowers in May and June, when cultivated oilseed rape (colza) and sunflower are not in bloom. During that period, pollen collection, honey production, and colony growth slow. An article published in the
|
The implication is that organically cultivated fields exert unique effects on the bee population. The swell in brood, destined to yield new workers, may be the result of a wider diversity of pollen resources or of lower mortality from local application of pesticides. The surge in honey reserves may reflect availability of melliferous flowers in greater numbers -- and over a greater area, corresponding to the range covered by bees in their quest for resources (one to three kilometres in zones where large farm fields are found).This study was made possible through Ecobee (INRA/CNRS), a unique bee colony monitoring system. Ecobee uses annual data from 50 experimental hives in southwest France to measure the effects of farming practices under real conditions. Previous research conducted by the same team showed that shrinking of brood during the period of flower scarcity resulted in lower colony survival in winter. The present study shows that organic farming can blunt the negative effects of intensive agriculture and increase the survival of bees, which play essential roles as pollinators.
|
Agriculture & Food
| 2,019 |
June 25, 2019
|
https://www.sciencedaily.com/releases/2019/06/190625102430.htm
|
Video games offer clues to help curb animal disease outbreaks
|
Strengthening biosecurity is widely considered the best strategy to reduce the devastating impact of disease outbreaks in the multi-billion-dollar global swine industry, but successfully doing so all comes down to human decision-making, a University of Vermont study shows.
|
The study, published June 25, 2019 in "We've come to realize that human decisions are critical to this picture," said Gabriela Bucini, a postdoctoral researcher in UVM's Dept. of Plant and Soil Science and lead author of the study. "We are talking about incredibly virulent diseases that can be transmitted in tiny amounts of feed and manure. Ultimately, controlling these diseases is up to the people in the production system who decide whether or not to invest and comply with biosecurity practices."Seeking to understand the role of human behavior in animal disease outbreaks, the researchers designed a series of video games in which players assumed the roles of hog farmers and were required to make risk management decisions in different situations. Observing how players responded to various biosecurity threats provided data used to simulate the spread of Porcine Epidemic Diarrhea virus (PEDv) -- one of the most severe infectious diseases in the U.S. swine industry -- in a regional, real-world hog production system.The number of pigs that contracted PEDv was shown to be highly dependent on the risk attitudes of the farmers and producers in the system and a relatively small shift in risk attitudes could have a significant impact on disease incidence. According to the study, getting just 10 percent of risk tolerant farmers to adopt a risk averse position with stronger biosecurity measures reduced the total incidence of PEDv by 19 percent. Keeping the disease under control required at least 40 percent of risk-takers to change their attitudes."The risk attitudes and human decisions that we're incorporating in the model are really powerful," said Scott Merrill, co-author and researcher in the Dept. of Plant and Soil Science and Gund Institute for the Environment. "If we can change the way people behave, then we have a chance to make some dramatic impacts and avoid a devastating outbreak."Merrill and Bucini are part of a team of researchers in UVM's Social Ecological Gaming and Simulation (SEGS) Lab who are designing interactive "serious" games and computational models to understand complex systems. Developed by Merrill, along with Chris Koliba and Asim Zia in the Dept. of Community Development and Applied Economics and Gund Institute for the Environment, the SEGS Lab places research subjects in a virtual world where researchers can monitor their behavior -- an approach that may help eliminate some of the biases that can occur with traditional surveys.Their work in the area of animal disease biosecurity is part of a $7.4 million multi-institutional biosecurity initiative led by UVM animal science researcher Julie Smith that's aiming to inform policies that collectively reduce the impact of pests and diseases on food-producing livestock in the U.S.The PEDv outbreak model is grounded in data derived from the biosecurity video games, which found that people behaved differently depending on the type of information they received and how it was presented. In one game, players were given several different risk scenarios and had to decide whether to maximize their profit or minimize their risk. Players presented with a 5 percent risk of their animals getting sick if they ignored biosecurity protocols complied only 30 percent of the time. However, when the risk level was presented visually as "low risk" on a threat gauge with some built in uncertainty, rather than numerically, players complied over 80 percent of the time."A simple thing like going out the wrong barn door can have a huge impact," said Merrill. "With the game data, we can see big differences in the economic and disease dynamics as we change the type of information we're delivering, and the way it's delivered."Infectious diseases like PEDv pose a continuous risk to U.S. hog producers, one that is increasing with the consolidation and globalization of the industry. The diseases are highly contagious and the effects can be catastrophic. PEDv was first detected in the U.S in 2013. Within one year, it spread to 33 states and wiped out as many as 7 million pigs, or 10 percent of the nation's agricultural swine population.Since then, U.S. producers have ramped up biosecurity measures, but PEDv remains endemic in the U.S. and new and emerging pests and diseases are on the rise. An ongoing outbreak of African swine fever in Asia has decimated pig herds across China, the world's largest consumer of pork, and pork prices are expected to hit record levels in 2019."Biosecurity efforts are often voluntary, but are critical to prevention, especially when there are no vaccines or treatments available," said Smith, principal investigator of UVM's animal disease biosecurity project. "We have to understand where people are on the risk continuum, their barriers and challenges, and their ability to act. That information is critical to the response."The Animal Disease Biosecurity Coordinated Agriculture Project is funded with a National Institute of Food and Agriculture (NIFA) grant from the U.S. Department of Agriculture, under award number 2015-69004-23273. Collaborating research and extension faculty are based at the University of Central Florida, Iowa State University, Kansas State University, Montana State University and Washington State University.
|
Agriculture & Food
| 2,019 |
June 24, 2019
|
https://www.sciencedaily.com/releases/2019/06/190624204847.htm
|
Crop pests more widespread than previously known
|
Insects and diseases that damage crops are probably present in many places thought to be free of them, new research shows.
|
Pests that have not been reported in a certain area are usually assumed to be absent, but analysis by the University of Exeter shows many pests are "currently unobserved, but probably present" (a likelihood of more than 75%).The study identified large numbers of pests in this category in China, India, southern Brazil and some countries of the former USSR.The researchers used data for 1,739 pests in the Centre for Agriculture and Bioscience International (CABI) pest distribution database."Our model allows us to quantify the risk that a certain pest is present in a certain place," said Dr Dan Bebber, of the University of Exeter."Our trick for testing model accuracy was to use pest observations from China published in the Chinese literature, which have not yet been incorporated into global pest databases."A lot of species that people are worried about finding in certain places are probably already there."That early stage is crucial if we want to stop the spread -- so these are the pests we should be focussing our efforts on."The discovery of crop pests and pathogens in new areas has accelerated in recent years, driven primarily by global trade, but also potentially by climate change.Targeting areas where new pests are probably present -- or are highly likely to arrive -- could be a key aspect of tackling their spread and reducing the resulting crop damage."Prior studies have often assumed that unreported pests in a global distribution database represent a true absence," Dr Bebber said."Our analysis provides a method for quantifying these 'pseudo-absences' to enable improved distribution modelling and risk analysis."
|
Agriculture & Food
| 2,019 |
June 24, 2019
|
https://www.sciencedaily.com/releases/2019/06/190624204755.htm
|
Ant farmers boost plant nutrition
|
Humans began cultivating crops about 12,000 years ago. Ants have been at it rather longer. Leafcutter ants, the best-known insect farmers, belong to a lineage of insects that have been running fungus farms based on chopped-up vegetable matter for over 50 million years. The ant farming of flowering plants, however, started more recently, about 3 million years ago in the Fiji Islands.
|
Research, led by Dr Guillaume Chomicki from the Department of Plant Sciences, University of Oxford, has demonstrated that millions of years of ant agriculture has remodelled plant physiology. Farming ants deposit nitrogen-rich faeces directly inside plants, which has led to the evolution of these ultra-absorptive plant structures. This means that ant-derived nutrients are actively targeted on the hyper-absorptive sites, rather than deposited as a result of by-products. This new understanding may offer important clues in our fight for food security.Dr Chomicki, the lead author of the study, says: 'The speed at which plants can take up nitrogen is a key limitation to plant growth rate. Most plants, including our crops, take up nitrogen from the soil and are thus not naturally exposed to very high nitrogen concentrations. Here, for millions of years, ants have deposited nitrogen-rich faeces directly inside the plants.' Ongoing work aims to decipher the genetic basis of the ultra-absorptive plant structures discovered in this study, which may ultimately be transferred to our crops and thereby increase their nitrogen uptake rate.It's a unique kind of farming where the ants grow not only their food, but also their home: the plants provide ready-made cavities in which the ants nest. This relationship is essential for both parties: the ants have lost the nest-building ability that most other tropical tree-dwelling ants have, and the plants -- which are epiphytes (plants growing on the surface of trees) -- rely on ants for nutrients and defence.To test whether the ant-farmed plants' nutrition has itself changed, Chomicki tracked the deposition of nutrients by ants inside these Fiji-island plants. In the farmed plant species, specialized ants exclusively defecate on hyper-absorptive warts on the walls inside the plant. In closely-related non-farmed plant species living in the same Fijian rainforests, the ants do not show this farming behaviour. This research shows that similar hyper-absorptive warts have evolved repeatedly in plants colonized by farming ants.The research published today in Professor Renner, from the University of Munich, and senior author of the study, said: 'Domestication of plants by ants has led to a >2-fold increase in uptake of ant-derived nitrogen, and this tight nutrient recycling is a key asset for the epiphytes to live in soilless canopies.'This supports the notion that millions of years of ant agriculture have remodelled plant physiology, shifting from ant-derived nutrients as by-products to active and targeted fertilization on hyper-absorptive sites. Much like our emerging 'precision agriculture' where computer-controlled devices and drones are used to target nutrients to the spots in the field where they are most needed, these ants have evolved a special kind of precision farming. They target nutrients to specific tissues in the plants that are hyper-absorptive.
|
Agriculture & Food
| 2,019 |
May 5, 2021
|
https://www.sciencedaily.com/releases/2021/05/210505090257.htm
|
Coral fights back against crown of thorns starfish
|
Coral are not completely defenceless against attacking juvenile crown of thorns starfish and can fight back to inflict at times lethal damage, new research has found.
|
This occurs during a period of the crown of thorns starfish life cycle, where small juveniles shift from a vegetarian diet of algae to coral prey. But this change in diet makes the juveniles more vulnerable to attack by coral.Population outbreaks of adult crown of thorns starfish, alongside coral bleaching is one of the greatest threats to tropical reef habitats.Video footage shows when the tube feet (small tube-like projections on the underside of a starfish's arm used for movement) of juvenile crown of thorns starfish reaches out to touch the coral, the entire arm curls back to avoid the corals' defensive stinging cells. To protect themselves, coral polyps have stinging cells in their sweeper tentacles and outer tissue called nematocysts, that are also used to capture food.This encounter damages the arms of juvenile crown of thorn starfish, delaying their growth into adulthood. Researchers also saw a 10 percent fatality rate among the juvenile crown of thorns starfish they studied. However, most juveniles that survived arm damage were able to regenerate partially lost arms.The research, published in The researchers emphasise the results give a fascinating insight into coral behaviour but the behaviour is not enough to protect it from other threats such as human-caused climate change, overfishing and water pollution.Ms Deaker says the period when young crown of thorns starfish shift from a vegetarian diet to eating coral, which is an animal, is a critical one. This is because young crown of thorns starfish who survive have the potential to contribute to population outbreaks that could devastate tropical reefs and coral.Previous research led by Ms Deaker and Professor Byrne has shown juvenile starfish can survive on algae for more than six years when they were previously thought to change diets at four months old, lying in wait until there is an abundance of coral.Marine biologists have reported seeing injured juvenile starfish and have suggested that it may be been caused by predators."However, seeing it caused by coral came as a complete surprise," said Ms Deaker."This shows that the coral use stinging cells as protection to strike back in an attempt to give itself a fighting chance against attacking coral predators."In the study, Ms Deaker and Professor Byrne, along with colleagues at the national Marine Science Centre, Coffs Harbour, monitored the condition, growth and survival of 37 juvenile crown of thorns in isolation away from potential predators and reared them on a diet of coral prey for over 3 months.They found coral stings caused injuries that severely reduced the arm length of the starfish by up to 83 percent.37.8 percent of juveniles were damaged by coral and four juveniles (10.8 percent) with severe injuries did not recover and died.The sting attacks from the coral also delayed the growth of juveniles, extending the time they need to maintain a vegetarian diet.The young starfish had a reflex response to being stung when they encountered coral. Their arms recoiled and twisted when their tube feet came into contact with the coral polyps."Sometimes the juveniles never recovered and died, but in most cases injured juveniles recovered and can regenerate their arms in about 4 months," said Ms Deaker."Despite being prey of crown of thorns starfish, coral can potentially influence the survival of juveniles and the appearance of a population outbreak on a reef by delaying their transition into an adult that can reproduce."Armed with these observations, the study shows that coral are a risky food choice for young crown of thorns starfish.Although coral injury was able to slow down the growth of the juvenile starfish, their ability to regenerate shows the resilience of this reef predator as a highly prolific species.Professor Byrne said: "The importance of this study in showing the disconnect between size and age of the juveniles reinforces how challenging it is to understand the dynamics of adult population replenishment."Video:
|
Animals
| 2,021 |
May 4, 2021
|
https://www.sciencedaily.com/releases/2021/05/210504191548.htm
|
Without commuter traffic, pandemic-era drivers are speeding up, increasing noise pollution
|
As pandemic lockdowns went into effect in March 2020 and millions of Americans began working from home rather than commuting to offices, heavy traffic in America's most congested urban centers -- like Boston -- suddenly ceased to exist. Soon afterwards, the air was noticeably cleaner. But that wasn't the only effect. A team of Boston University biologists who study how human-related sounds impact natural environments seized the opportunity to learn how the reduced movement of people would impact local ecosystems. They found -- surprisingly -- that sound levels increased in some nature conservation areas, a result of cars driving faster on roads no longer choked by traffic.
|
BU ecologist Richard Primack and Carina Terry, an undergraduate student working in Primack's research lab, ventured into Boston-area parks, iPhones in hand, to take environmental sound recordings to see how sound levels had changed in comparison to pre-pandemic times, when there were more people out and about, construction underway, and cars on the road. Primack, a BU College of Arts & Sciences professor of biology, has studied noise pollution for over four years and has trained over a hundred students and citizen conservationists to collect noise samples in nature sanctuaries across Massachusetts.The team focused their study on three locations in Massachusetts: Hammond Pond Reservation in Newton, Hall's Pond Sanctuary in Brookline, and Blue Hills Reservation -- by far the largest of the three -- which covers parts of Milton, Quincy, Braintree, Canton, Randolph, and Dedham. They collected noise samples from all three parks using a specialized sound-sensing app on iPhones, called SPLnFFT. Then, by referencing the Primack lab's huge library of previously collected sound data, the study authors compared sound levels collected in the months during the pandemic to measurements collected before the pandemic began. The resulting paper was recently published in the journal They found that Hammond Pond Reservation and Hall's Pond Sanctuary, both located in suburban residential areas, had lower levels of noise. But at Blue Hills Reservation, they found the opposite -- sound levels increased substantially in all areas of the park, "which was very surprising," Terry says. Blue Hills is a popular destination for local hikes and it is intersected by several major highways and roadways. While there are less cars on the roads these days, the researchers say their sound recordings indicate cars are moving much faster, generating more noise. This finding aligns with a trend that has been observed nationwide -- the pandemic has seen traffic jams replaced with increased reports of recklessly fast drivers speeding on open roadways."Before the pandemic, traffic was going relatively slow on [I-93] because it was so congested," says Primack, the study's senior author. Now, noise from faster-moving cars is "penetrating the entire park," he says, measuring about five decibels noisier, even in the interior of the park, compared to pre-pandemic times."It's not so much the [number] of cars, but the speed," says Terry, the study's lead author. This study was part of her undergraduate honors thesis from the department of earth and environment and the Kilachand Honors College which she graduated from in 2020, and won her the Francis Bacon Award for Writing Excellence in the Natural Sciences.For animals, road noise (and other forms of noise pollution like leaf blowers and airplanes overhead) can interfere with their ability to hear threats and communicate with each other, especially for certain birds who are vulnerable to predators or who have calls that can't penetrate through the noise. Noise pollution can then impact which species are able to survive in areas with high noise levels from human activity."There's an increasing volume of studies that say wildlife is very sensitive to noise pollution," Primack says. "Animals rely strongly on their hearing for detecting predators and social interactions.""The big impact [of noise pollution] is the filtering out of which species can live in an area, because if you have a species you need to conserve, you can't conserve them if they won't be able to survive in a loud area, or if the conservation area is right by a road," Terry says.There are also well-measured health effects of noise pollution on people, according to the researchers, including elevated blood pressure, heart attacks, inability to sleep, increasing irritability, mood changes, and anxiety."When you're [recreating] in a protected [nature conservation] area, people want to relax and experience a natural environment especially after being in the city all day," Primack says. "If people are hearing a lot of noise, it means they can't get the rejuvenating effects of the park."Primack and his lab will continue to measure noise pollution levels in Boston-area parks and around BU's campus, documenting how noise levels change as vaccinated people begin to repopulate offices, drive more, and resume more normal activities. Terry is applying to graduate school, where she hopes to pursue further research on wildlife ecology and human impacts on the environment.And for nature lovers behind the wheel, the takeaway from the study is clear: slow down.
|
Animals
| 2,021 |
May 4, 2021
|
https://www.sciencedaily.com/releases/2021/05/210504135741.htm
|
Bringing up baby: A crocodile's changing niche
|
Relatives of the giant crocodile might have been kings of the waterways during the Cretaceous period, eating anything -- including dinosaurs -- that got a little too close to the water's edge, but the largest of these apex predators still started off small. Figuring out how these little crocs grew up in a world surrounded by giants is no small task. Now crocs fossils from Texas are shedding light on how these animals changed their diets as they grew, helping them find a place of their own in environments alongside their bigger, badder relatives.
|
According to the study, published by Cambridge University Press, the crocodiless in question are members of the Having so many crocs from the same fossil population is not common, and the smaller, more delicate bones of juveniles often did not survive the fossilization process."So many fossil groups are only known from one or a handful of specimens," said paleontologist Stephanie Drumheller, lead author of the study and a lecturer of earth and planetary sciences at the University of Tennessee, Knoxville. "It can be easy to fall into the trap of only thinking about the adults." The researchers ran into challenges piecing together this ancient ecosystem, however. Living alongside "These two large croc species were comparable in size to an adult A smaller crocodile, Scolomastax, lived in the area as well, but its unusual jaw and chunky dentition hint that it preferred hard food and maybe even plants."These results confirm previous work that shows fossil crocs were much more diverse and creative when it came to coexisting in the same environments," said Chris Noto, co-author and associate professor at the University of Wisconsin-Parkside. "The very warm conditions of the Cretaceous supported a greater number of reptiles and allowed them to explore new niches not possible in the present day."When these crocodiles died, their skeletons fell apart as they fossilized, getting jumbled together and complicating efforts to tell which bones went with which animal. To help solve this puzzle, the team turned to 3D scanning technology to help reconstruct the skulls. UT undergraduate student Hannah Maddox meticulously scanned each piece and stitched them together into 3D models of complete skulls."It was like solving a great puzzle," said Maddox. "Every piece brought you closer to seeing a toothy grin that hadn't been seen in millions of years."As the models came together, a more complete picture of how The juveniles had lighter, skinnier snouts and teeth than their older relatives -- faces better suited to snap up quicker, softer prey than the heavier, powerful jaws of their parents. This might have helped make sure that little "This is an amazing fossil discovery where we not only have a population of a single species, but in an ecosystem that has multiple predators coexisting by filling separate niches," said Adams.Similar results were found in recent analyses of young tyrannosaurs, which spent their teenaged years outcompeting other medium-sized predators in their ecosystems.
|
Animals
| 2,021 |
May 3, 2021
|
https://www.sciencedaily.com/releases/2021/05/210503144729.htm
|
Mating with relatives? Not a big deal in nature
|
We usually assume that inbreeding is bad and should be avoided under all circumstances. But new research performed by researchers at Stockholm University, published in
|
The idea that animals should avoid mating with relatives has been the starting point for hundreds of scientific studies performed among many species. But it turns out the picture is more complicated."People assume that animals should avoid mating with a relative when given the chance," says Raïssa de Boer, researcher in zoology at Stockholm University. "But evolutionary theory has been telling us that animals should tolerate, or even prefer, mating with relatives under a broad range of conditions for more than four decades."The study provides a synthesis of 139 experimental studies in 88 species spanning 40 years of research, settling the longstanding debate between theoretical and empirical expectations about if and when animals should avoid inbreeding."We address the 'elephant in the room' of inbreeding avoidance studies by overturning the widespread assumption that animals will avoid inbreeding whenever possible," says Raïssa de Boer.The study demonstrates that animals rarely attempt to avoid mating with relatives, a finding that was consistent across a wide range of conditions and experimental approaches."Animals don't seem to care if their potential partner is a brother, sister, cousin or an unrelated individual when they are choosing who to mate with," says Regina Vega Trejo, a researcher at Stockholm University and an author of the paper.The study also looked at inbreeding avoidance in humans, comparing the results with similar experiments with animals."We compared studies that asked if humans avoid inbreeding when presented with pictures of faces that were digitally manipulated to make the faces look either more or less related to studies that used similar approaches in other animals. Just like other animals, it turns out that there is no evidence that humans prefer to avoid inbreeding," says Raïssa de Boer."Our findings help explain why many studies failed to find clear support for the inbreeding avoidance and offer a useful roadmap to better understand how cognitive and ecologically relevant factors shape inbreeding avoidance strategies in animals," says John Fitzpatrick an associate professor in Zoology at Stockholm University and the senior author of the study.The findings will have wide reaching implications for conservation biology. Mate choice is increasingly being used in conservation breeding programs in an attempt to the success of conservation efforts for endangered species. What does this mean?"A primary goal of conservation efforts is to maintain genetic diversity, and mate choice is generally expected to achieve this goal. Our findings urge caution in the application of mate choice in conservation programs," says John Fitzpatrick.
|
Animals
| 2,021 |
May 3, 2021
|
https://www.sciencedaily.com/releases/2021/05/210503135616.htm
|
Flatfish got weird fast due to evolutionary cascade
|
Ever look at a flatfish like a flounder or sole, with two eyes on one side of its head, and think, "How did that happen?"
|
You're in luck. Rice University biologist Kory Evans has the answer."Flatfishes are some of the weirdest vertebrates on the planet, and they got weird very, very fast by changing multiple traits at once over a short period of time," said Evans, an assistant professor of biosciences at Rice who specializes in studying the evolution of fish over long time scales.Of all mammals, reptiles, birds, amphibians and fish, flatfish are easily the most asymmetric. Evans, the corresponding author of a study on flatfish evolution in the "Imagine any other animal," he said. "Like, say you're out walking and you see a squirrel, and one eye is here and the other is there," he said, pointing to two places on the same side of his face. "That squirrel is having a bad time. And there are 800 species of these fish that just do that."Perspective helps for understanding how weird these animals actually are."In evolutionary terms, flatfish asymmetry isn't just a novelty, it's an innovation, and a trait that sets flatfish far apart from even their closest relatives.Evans said flatfish evolution is particularly interesting because they began as typical, symmetrical fish. They started evolving their current shape, or morphology, about 65 million years ago, and within 3 million years, they'd largely finished."We got all that novel colonization of morphospace in 3 million years' time," Evans said. "And look how much time has passed since then. So there's a really brief and short period of time when they evolved all these new forms and all these crazy species."In their study, Evans and co-authors Olivier Larouche of Rice and Sara-Jane Watson of the New Mexico Institute of Mining and Technology found that tight integration of genetic traits in flatfish led to a sort of evolutionary cascade."Integration is where there's a high degree of correlation between traits, such that if you change one trait, another trait will be changed as well," Evans said. "At macroevolutionary timescales, this gets really interesting, because traits then begin to co-evolve with one another. So if you change one trait, you might end up changing several others."He said traits can become more integrated if their morphological development is controlled or influenced by shared gene interaction networks."If the signaling networks expand to encompass more and more traits, then you can theoretically smear changes all across an entire organism using the same signaling network, and you can change really fast," he said. "It's like pressing one button and flipping the whole animal all at once."Evans, Larouche and Watson used several methods to piece together the story of flatfish evolution. One was a phylogenetic comparative method that tracks the evolutionary history of traits between and among species. Phylogenetic trees have branches that show where species diverge. "Typically, the tree is built using genetics," Evans said. "So, maybe we'll have a bunch of genomes for all those species. And we can use that to figure out who's more closely related to who. Then, once the tree is built, I can see how traits have changed over time using the branching pattern of the tree as a guide."The researchers also used a micro-CT scanner in the Evans lab to make 3D scans of the skulls of several flatfish species. The scans were used to make 3D morphometric models that could be compared for differences in shape. But many flatfish species are so dissimilar that it wasn't possible to "tease them apart with just shape or just phylogeny alone," Evans said.So the researchers created complex mathematical models to track the degree of integration between different regions of the skull across the 65-million-year history of flatfishes and their relatives."We found that flatfishes were way more integrated than non-flat fishes, and what this means is that the evolution of asymmetry for flatfishes ended up being an integrated process, basically, involving changes all across the skull," he said. "As the eye migrated, a bunch of other things changed as well. And it became additive. So as the flatfish skull got more and more integrated, more things began to change, per unit time, than a generation before."As to why flatfish evolved to be asymmetrical, Evans said it wasn't the only path to becoming flat."Other fishes that are flat did not do this, like stingrays," he said. "They just went flat like a pancake. But their eyes aren't both on the same side. The remora (aka suckerfish) are also a flat-looking fish, and they didn't do that."Given evolution is a competition for "survival of the fittest," the evolutionary success of flatfish begs the question: Is asymmetry somehow advantageous?"I'm not gonna lie," Evans said. "I don't really know if there's an advantage. I think they did it because they could."
|
Animals
| 2,021 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.