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March 13, 2020
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https://www.sciencedaily.com/releases/2020/03/200313180741.htm
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Long-term analysis shows GM cotton no match for insects in India
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Genetically modified (GM) Bt cotton produces its own insecticide. The seeds were introduced in India in 2002 and today account for 90% of all cotton planting in the country. Bt cotton is now the most widely planted GM crop on small farms in the developing world.
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In India, Bt cotton is the most widely planted cotton crop by acreage, and it is hugely controversial. Supporters long touted increased yields and reduced pesticides to justify its pickup. But that argument does not hold up under the first long-term study of Bt cotton impacts in India. The analysis is co-authored by a Washington University in St. Louis anthropologist in the journal Bt cotton is explicitly credited with tripling cotton production during 2002-2014. But the largest production gains came prior to widespread seed adoption and must be viewed in line with changes in fertilization practices and other pest population dynamics, according to Glenn Davis Stone, professor of sociocultural anthropology and environmental studies, both in Arts & Sciences."Since Bt cotton first appeared in India there has been a stream of contradictory reports that it has been an unmitigated disaster -- or a triumph," Stone said, noting the characteristic deep divide in conversation about GM crops. "But the dynamic environment in Indian cotton fields turns out to be completely incompatible with these sorts of simplistic claims."Many economists and other observers based their assessments on much shorter time frames than Stone's new study, which spans 20 years."There are two particularly devastating caterpillar pests for cotton in India, and, from the beginning, Bt cotton did control one of them: the (misnamed) American bollworm," Stone continued. "It initially controlled the other one, too -- the pink bollworm -- but that pest quickly developed resistance and now it is a worse problem than ever."Bt plants were highly vulnerable to other insect pests that proliferated as more and more farmers adopted the crop. Farmers are now spending much more on insecticides than before they had ever heard of Bt cotton. And the situation is worsening."Stone, an internationally recognized expert on the human side of global agricultural trends, has published extensively on GM crops in the developing world. His previous work has been funded by the Templeton Foundation and the National Science Foundation.To prepare this new analysis, Stone partnered with entomologist K.R. Kranthi, the former director of India's Central Institute for Cotton Research. Kranthi is now the head of a technical division at the Washington-based International Cotton Advisory Committee."Yields in all crops jumped in 2003, but the increase was especially large in cotton," Stone said. "But Bt cotton had virtually no effect on the rise in cotton yields because it accounted for less than 5% of India's cotton crop at the time."Instead, huge increases in insecticides and fertilizers may have been the most significant changes."Now farmers in India are spending more on seeds, more on fertilizer and more on insecticides," Stone said. "Our conclusion is that Bt cotton's primary impact on agriculture will be its role in making farming more capital-intensive -- rather than any enduring agronomic benefits."
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Agriculture & Food
| 2,020 |
March 13, 2020
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https://www.sciencedaily.com/releases/2020/03/200313155308.htm
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How plants sound the alarm about danger
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Just like humans and other animals, plants have hormones. One role of plant hormones is to perceive trouble -- whether an insect attack, drought or intense heat or cold -- and then signal to the rest of the plant to respond.
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A multicenter team led by current and former investigators from the Salk Institute is reporting new details about how plants respond to a hormone called jasmonic acid, or jasmonate. The findings, which were published in "This research gives us a really detailed picture of how this hormone, jasmonic acid, acts at many different levels," says Professor Joseph Ecker, co-corresponding author and Howard Hughes Medical Institute investigator. "It enables us to understand how environmental information and developmental information is processed, and how it ensures proper growth and development."The plant used in the study was "Jasmonic acid is particularly important for a plant's defense response against fungi and insects," says co-first author Mark Zander, a staff researcher in Ecker's lab. "We wanted to precisely understand what happens after jasmonic acid is perceived by the plant. Which genes are activated and deactivated, which proteins are produced and which factors are in control of these well-orchestrated cellular processes?"The researchers started with plant seeds grown in petri dishes. They kept the seeds in the dark for three days to mimic the first few days of a seed's life, when it is still underground. "We know this growth stage is super important," says co-first author and co-corresponding author Mathew Lewsey, an associate professor at La Trobe University in Melbourne, Australia, who previously worked in Ecker's lab. The first few days in the soil are a challenging time for seedlings, as they face attacks from insects and fungi. "If your seeds don't germinate and successfully emerge from the soil, then you will have no crop," Lewsey adds.After three days, the plants were exposed to jasmonic acid. The researchers then extracted the DNA and proteins from the plant cells and employed specific antibodies against their proteins of interest to capture the exact genomic location of these regulators. By using various computational approaches, the team was then able to identify genes that are important for the plant's response to jasmonic acid and, moreover, for the cellular cross-communication with other plant hormone pathways.Two genes that rose to the top in their degree of importance across the system were MYC2 and MYC3. These genes code for proteins that are transcription factors, which means that they regulate the activity of many other genes -- or thousands of other genes in this case."In the past, the MYC genes and other transcription factors have been studied in a very linear fashion," Lewsey explains. "Scientists look at how one gene is connected to the next gene, and the next one, and so on. This method is inherently slow because there are a lot of genes and lots of connections. What we've done here is to create a framework by which we can analyze many genes at once.""By deciphering all of these gene networks and subnetworks, it helps us to understand the architecture of the whole system," Zander says. "We now have this very comprehensive picture of which genes are turned on and off during a plant's defense response. With the availability of CRISPR gene editing, these kinds of details can be useful for breeding crops that are able to better withstand attacks from pests."Another noteworthy aspect of this work is that all of the data from the research has been made available on Salk's website. Researchers can use the site to search for more information about genes they study and find ways to target them.
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Agriculture & Food
| 2,020 |
March 13, 2020
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https://www.sciencedaily.com/releases/2020/03/200313112113.htm
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New planting guidelines could boost edamame profits
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Edamame may be a niche crop in the United States, but growers and processors still need the best possible information to make sound management decisions. That's why USDA Agricultural Research Service (USDA-ARS) and University of Illinois researchers are making new plant density recommendations for machine-harvested edamame, at less than half the rate suggested by seed companies.
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"Until now, edamame processors and growers had no research-based information to determine crop density. While some seed companies make recommendations, the basis for these recommendations is unclear," says Marty Williams, ecologist with USDA-ARS and the Department of Crop Sciences at Illinois.Seed companies recommend plant densities from 80,100 to 139,200 plants per acre, and at $11 to $22 per pound of edamame seed, the cost adds up very quickly. Williams says these recommendations may be based on what works for grain-type soybean, but they're not necessarily appropriate for edamame, which is harvested while pods are bright green and seeds are still immature.To get a better handle on what's realistic and profitable for the crop, Williams and crop sciences graduate student Daljeet Dhaliwal planted four edamame cultivars at five densities, ranging from 10,000 to 160,000 plants per acre. They measured multiple growth, harvest, and processing characteristics for each cultivar at all five densities, over two years. Finally, they derived the economically optimal planting density (EOPD) based on the cost of seed, yield of marketable pods, and sales price."Results identified that the EOPD for machine-harvested edamame ranged from 35,200 to 48,600 plants per acre," Dhaliwal says. "That's less than half of what's recommended by seed companies."Lower densities were more profitable, in part, because increasing plant density led to a lower ratio of pod mass to vegetative mass."We showed that higher plant densities change the architecture of the crop. For the most part, as plants are added beyond the EOPD, the crop is less suitable for mechanical harvest. It's taller, with more leaf area, and fewer marketable pods. Obviously, we need enough plants to utilize available resources, but there are diminishing returns beyond the EOPD," Williams says.The new report underscores that edamame agronomy is not interchangeable with grain-type soybean. For the U.S. edamame market to maximize profitability and become competitive with China, Williams says, growers and processors should follow research-backed recommendations specific to the unique aspects of the crop.
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Agriculture & Food
| 2,020 |
March 12, 2020
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https://www.sciencedaily.com/releases/2020/03/200312142325.htm
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Environmental footprint of California dairy cows over 50 years
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Producing a liter of milk in California emits less greenhouse gas and uses less land and water than it did in 1964, according to a recent study from researchers at the University of California, Davis.
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"We compared 1964 through 2014 and found a 50 percent reduction in greenhouse gases to produce the same quantity and quality of milk," said senior author Ermias Kebreab, professor and Sesnon Endowed Chair in the Department of Animal Science at UC Davis. "The magnitude of change is surprising."Scientists conducted a lifecycle environmental assessment of cows from the time they are born to the time they leave the farm gate. The study included such inputs as producing feed for the animals, and the machinery and transportation needed to produce milk.Cows belch methane, a potent greenhouse gas, as part of their digestive process. The study found the biggest emission cuts came from reductions in these emissions, known as enteric methane, compared to reductions in emissions from manure."Reductions in enteric methane intensity (i.e., methane emissions per gallon of milk) are primarily a result of better genetics and breeding and better nutrition for the animals," said Kebreab.In addition, water use in the industry has dropped by 88 percent, due primarily to efficient water use in feed crops and the use of crop byproducts for feed such as almond hulls. Water use in housing and milking also dropped by 55 percent.The amount of land it takes to produce a liter of milk compared to 1964 has also decreased. This is largely due to improvements in crop genetics and production practices that have increased yields of grain, hay and silage for cows on the same amount of land."We've saved an amount of land equal to the size of Connecticut," said Kebreab.Over the last 50 years, dairy production in California has undergone significant improvements and advancements in animal husbandry, feeding and housing practices, and in animal and plant genetics and crop production methods.Total greenhouse gas emissions from cows overall has increased in California as more cows are needed to feed a growing population. But cows are now producing much more milk. In the 1960s, one cow could produce about 4,850 kilograms of milk per year. Now a cow can produce more than 10,000 kg annually."There is a lot of discussion about how cows have a huge environmental footprint, but no one is talking about how the dairy industry has changed," said Kebreab. "Dairy farmers are doing a lot to help reduce the industry's environmental footprint."Scientists continue to look for ways to reduce enteric methane emissions through better animal nutrition, including feed additives. In a previous study, Kebreab found that feeding dairy cows a small amount of a seaweed called Asparagopsis armata along with their feed, reduced methane emissions by up to 60 percent.California is the top dairy producing state, and milk production is the third largest agricultural industry in the United States.The study was published in the
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Agriculture & Food
| 2,020 |
March 12, 2020
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https://www.sciencedaily.com/releases/2020/03/200312101043.htm
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A molecular map for the plant sciences
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Every cell of any organism contains the complete genetic information, or the "blueprint," of a living being, encoded in the sequence of the so-called nucleotide building blocks of DNA. But how does a plant create tissues as diverse as a leaf that converts light into chemical energy and produces oxygen, or a root that absorbs nutrients from the soil?
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The answer lies in the protein pattern of the cells of the respective tissue. Proteins are the main molecular players in every cell. They are biocatalysts, transmit signals inside and between cells, form the structure of a cell and much more."To form the protein pattern, it is not only important which proteins are present in a tissue, but, more importantly, in what quantities," explains Bernhard Kuster, Professor of Proteomics and Bioanalytics at TUM. For example, proteins of the photosynthesis machinery are found primarily in leaves, but also in seeds, yet at a thousand times lower levels.The team around Dr. Julia Mergner and Prof. Bernhard Kuster examined the model plant Arabidopsis thaliana, or thale cress, using biochemical and analytical high-throughput methods to find out more about the molecular composition.For 40 years, this rather inconspicuous weed with small white flowers has been the "laboratory mouse" of plant biology. It is small, generally undemanding and easy to grow. These properties have paved the way for its frequent us in genetics and molecular biology. The fact that insights from basic research on Arabidopsis can often be transferred to crop plants also makes Arabidopsis interesting for plant breeding research.Most of the data was generated using a method called liquid chromatography-tandem mass spectrometry, which enables the analysis of thousands of proteins in parallel in one experiment and bioinformatics methods helped analyze the huge amounts of data."For the first time, we have comprehensively mapped the proteome, that is, all proteins from the tissues of the model plant Arabidopsis," explains Bernhard Kuster. "This allows new insights into the complex biology of plants."All results of the research work were summarized in a virtual atlas which provides initial answers to the questions:All data is freely available in the online database ProteomicsDB, which already contains a protein catalog for the human proteome, which the same team at TUM decoded in 2014.One can anticipate that there are similarities between Arabidopsis and the molecular maps of other plants. "The Atlas should, therefore, also inspire research on other plants," says Kuster.In the future, the researchers will turn their attention to the analysis of crops. Of particular interest will be to investigate how the proteome changes when plants are attacked by pests or how plants can adapt to climate change.
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Agriculture & Food
| 2,020 |
March 11, 2020
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https://www.sciencedaily.com/releases/2020/03/200311161902.htm
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Natural habitat around farms a win for strawberry growers, birds and consumers
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Conserving natural habitat around strawberry fields can help protect growers' yields, their bottom line and the environment with no detectable threat to food safety, indicates a study led by the University of California, Davis.
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In the study, published in the journal "Our results indicate that strawberry farmers are better off with natural habitat around their farms than without it," said lead author Elissa Olimpi, a postdoctoral researcher in the lab of Daniel Karp, assistant professor with the UC Davis Wildlife, Fish and Conservation Biology department.The study's models indicate that adding natural habitat can decrease crop damage costs by 23 percent. Removing natural habitat can increase costs up to a whopping 76 percent.Critically, farms with more natural habitat showed no evidence of higher fecal contamination on or surrounding strawberry plants. Also, while bird feces were regularly encountered on the ground, only 2 of 10,000 berries examined showed signs of direct fecal contamination. Those berries would be removed from food production during the hand-harvesting process."We found no evidence that conserving habitat presented a food safety risk," Olimpi said.The results run contrary to market-driven farm management practices that encourage habitat removal to decrease bird fecal contamination and crop damage. Natural habitat includes forests, grasslands, wetlands, and shrubs.Those measures were developed in response to a deadly outbreak of E. coli in 2006 that was traced to spinach grown in the region. Since then, private food safety protocols and public regulations were designed to help avert further foodborne illness crises. Yet some requirements may compromise environmental and social sustainability, as a 2019 study by Olimpi describes.Between 2006 and 2009, roughly 13 percent of the riparian habitat along the Salinas River was removed in response to food safety reforms, notes a 2013 study.The study notes that wild birds did create crop damage in some cases, particularly at the edges of farms. And while they help control insects, some of those are beneficial insects. But overall, the presence of natural habitat muted the effects of birds on farms and associated damage costs.In other words, says Olimpi: "No matter your crop damage, birds will be more beneficial when you have natural habitat. We think the natural habitat is providing what they need, so the strawberry field isn't this oasis for them."The work is part of a larger research goal to explore how agricultural landscapes can both support and benefit from biodiversity and ecological communities."The future of many species hinges on them being able to survive in working landscapes," Olimpi said. "If we can find those opportunities in agriculture where we can enhance biodiversity and production, that's the golden ticket."The study was funded by a grant from the U.S. Department of Agriculture's National Institute of Food and Agriculture.
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Agriculture & Food
| 2,020 |
March 11, 2020
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https://www.sciencedaily.com/releases/2020/03/200311111958.htm
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Acacia bushlands prevent climate warming in Eastern Africa
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Changes to the vegetation cover of land surfaces constitutes the biggest cause of increasing carbon dioxide emissions after the use of fossil fuels. Particularly in Africa, forests and bushland are continuously cleared for the requirements of farming and food security. The climate effects of forest loss have been extensively investigated, but now new information on the significance of bushlands in the prevention of climate change has also been uncovered.
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A recently completed doctoral dissertation at Earth Change Observation Laboratory of the University of Helsinki posits that converting bushland into agricultural land raises land surface temperatures almost as much as forest loss. Clearing bushland for cultivation also reduces the carbon stocks held by the above ground vegetation and carbon is also released into the atmosphere from the soil when preparing it for crops.The consequences result in warming microclimates. Once the process is replicated in the neighbouring hectares, square kilometres, counties and throughout Eastern Africa, the consequences start affecting the climate of the entire continent.In his doctoral dissertation in the field of geoinformatics, Ethiopia-born Temesgan Abera looks into the effect of changes in vegetation on the climate of the Horn of Africa and the lowlands surrounding the Taita Hills in Eastern Africa.According to the study, clearing forests and turning them into arable land raises the temperature of the land surface locally by 1.8°C compared to savannahs and bushland. The decrease in evapotranspiration or water evaporation from land surface and vegetation, had an impact on surface warming up to 10 times stronger than the cooling effect of the increase of albedo, which was -0.12°C. Converting bushland into farmland increased the land surface temperature to a magnitude comparable to that of forest clearing.Satellite remote sensing data that reveal the expansion of farmlands and the reduction of acacia-dominated bushland, otherwise typical to the region, were utilised in the study. Also available were meteorological data on rainfall and temperature collected at the Taita Research Station and by the Kenya Meteorological Department. Changes occurring in the long run between wet and dry seasons were successfully measured.The findings can be utilised to assess climate models and observation-based studies on a global scale focused on the biogeophysical effects of land cover changes.The doctoral dissertation is part of SMARTLAND, an extensive research project funded by the Academy of Finland and headed by Professor of Geoinformatics Petri Pellikka, which investigates the effects of climate change in Eastern Africa and looks for solutions to mitigate climate change. In addition to Pellikka, the dissertation was supervised by researchers Eduardo Maeda and Janne Heiskanen. The Taita Research Station of the University of Helsinki in Kenya served as the base for the fieldwork stage of the study.Temesgen Abera, MSc, defended his doctoral dissertation entitled 'Climatic impacts of vegetation dynamics in Eastern Africa' in the Faculty of Sciences, University of Helsinki, on 6 March 2020. The thesis can be accessed through the University of Helsinki E-thesis service:
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Agriculture & Food
| 2,020 |
March 11, 2020
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https://www.sciencedaily.com/releases/2020/03/200311082946.htm
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Microbes play important role in soil's nitrogen cycle
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Under our feet, in the soil, is a wealth of microbial activity. Just like humans have different metabolisms and food choices, so do those microbes. In fact, microbes play an important role in making nutrients available to plants.
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A recent review paper from Xinda Lu and his team looks at different roles that various soil microbes have in soil's nitrogen cycle. Lu is a researcher at Massachusetts Institute of Technology.According to Lu, "Soil microbes catalyze most of the transformations of soil nitrogen into plant-usable forms. Diverse microbes use different processes -- and sometimes work together. Knowing the various styles of soil microbes, and linking microbes to specific soil processes, can be important knowledge for farmers."Modern nitrogen fertilizers are applied in the form of ammonium. Through a biological process called nitrification, soil microbes convert ammonium to nitrates that plants can absorb. In order to be efficient at this process, microbes need oxygen. Researchers are studying nitrification because it can be linked to greenhouse gases and loss of fertilizer.Although microbiologists have been studying the nitrogen cycle for over a century, not all steps were well understood. New microorganisms have recently been identified. A type of prokaryote (single-celled organism) called archaea has also been playing a role in nitrification.Archaea are not technically soil bacteria, due to their structure. There are many more archaea that contribute to nitrification in some soils than there are bacteria responsible for the same activity. Including the role of archaea in nitrification has broadened the understanding of scientists and researchers.Researchers reviewed various studies of soil nitrification. This included the abundance of microbes in soil in relation to various environmental factors. Soil pH, temperature and the ratio of soil carbon to soil nitrogen were all compared to the number of microbes in each soil sample. Soil depth and other factors also influence microbe abundance.Previous studies have shown, for example, that nitrification archaea are more abundant than bacteria in warmer temperatures. Other microbes thrive in lower temperatures.Soil pH also influences how active soil microbes are in the nitrification process. Soil bacteria Nitrospira were more dominant in acidic soils, including forests and farm fields.Researchers have also studied how various microbes "talk" to each other. This keeps the nitrification process running smoothly. Various mechanisms have been proposed, including cell signaling. The presence of nitric oxide in soils may enhance interactions between microbes.Soil scientists are sure they have not found all the microbes that contribute to the vast array of services soils provide. Just as astronomers discover new stars in the sky as tools advance, so will soil microbiologists find new soil microbes. Some may be involved in nitrification.Collecting and cataloging the type, abundance and location of soil microbes will continue to advance the knowledge we have about the soil nitrogen cycle.The review was recently published in
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Agriculture & Food
| 2,020 |
March 9, 2020
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https://www.sciencedaily.com/releases/2020/03/200309130101.htm
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New viable CRISPR-Cas12b system for plant genome engineering
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In a new publication in
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"This is the first demonstration of this new CRISPR-Cas12b system for plant genome engineering, and we are excited to be able to fill in gaps and improve systems like this through new technology," says Qi. "We wanted to develop a full package of tools for this system to show how useful it can be, so we focused not only on editing, but on developing gene repression and activation methods."It is this complete suite of methods that has ultimately been missing in other CRISPR systems in plants. The two major systems available before this paper in plants were CRISPR-Cas9 and CRISPR-Cas12a. CRISPR-Cas9 is popular for its simplicity and for recognizing very short DNA sequences to make its cuts in the genome, whereas CRISPR-Cas12a recognizes a different DNA targeting sequence and allows for larger staggered cuts in the DNA with additional complexity to customize the system. CRISPR-Cas12b is more similar to CRISPR-Cas12a as the names suggest, but there was never a strong ability to provide gene activation in plants with this system. CRISPR-Cas12b provides greater efficiency for gene activation and the potential for broader targeting sites for gene repression, making it useful in cases where genetic expression of a trait needs to be turned on/up (activation) or off/down (repression)."When people think of CRISPR, they think of genome editing, but in fact CRISPR is really a complex system that allows you to target, recruit, or promote certain aspects already in the DNA," says Qi. "You can regulate activation or repression of certain genes by using CRISPR not as a cutting tool, but instead as a binding tool to attract activators or repressors to induce or suppress traits."This ability gives CRISPR-Cas12b an edge over CRISPR-Cas12a, particularly when gene activation is the goal. Additionally, the system retains all the positives that were inherent in CRISPR-Cas12a for plants, including the ability to customize cuts and gene regulation across a broad range of applications. In fact, Qi and his lab were even able to repurpose the CRISPR-Cas12b system for multiplexed genome editing, meaning that you can simultaneously target multiple genes in a single step."Added complexity allows targeting of more specific or other effectors for gene activation, repression, or even epigenetic changes," says Qi. "This system is more versatile because we can play with more modifications, more domains, and there are therefore more opportunities to engineer the whole system. Only when you have this kind of hybrid system with more complexity do you get the most robust gene activation and editing capabilities."The initial work for CRISPR-Cas12b completed in this paper was conducted in rice, which is already a major global crop. However, Qi and his lab hope to explore more systems to further enhance and improve plant genome engineering, including developing applications to additional crops."This type of technology helps increase crop yield and sustainably feed a growing population in a changing world. In the end, we are talking about broad impact and public outreach, because we need to bridge the gap between what researchers are doing and how those impacts affect the world," stresses Qi.This work is funded by the National Science Foundation (NSF Award No. IOS-1758745) and the National Institute of Food and Agriculture, United States Department of Agriculture (USDA-NIFA Award No. 2018-33522-28789).
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Agriculture & Food
| 2,020 |
March 6, 2020
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https://www.sciencedaily.com/releases/2020/03/200306122507.htm
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Damaging impacts of warming moderated by migration of rainfed crops
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Many studies seek to estimate the adverse effects of climate change on crops, but most research assumes that the geographic distribution of crops will remain unchanged in the future.
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New research using 40 years of global data, led by Colorado State University, has found that exposure to rising high temperatures has been substantially moderated by the migration of rainfed corn, wheat and rice. Scientists said continued migration, however, may result in significant environmental costs.The study, "Climate adaptation by crop migration," is published March 6 in "There's substantial concern about the impacts of climate change on agriculture and how we can adapt to those changes," said Nathan Mueller, assistant professor in the Department of Ecosystem Science and Sustainability at CSU and a senior author on the paper."We often think about how farmers can adapt to shifting climate conditions by changing crop varieties or planting dates. But farmers have also been changing what crops they are growing over time, collectively leading to large-scale shifts in crop distribution. This pathway of adaptation has been underexplored."Using new, high-resolution datasets on crop areas around the world, the research team analyzed the location of crops, climate, and irrigation from 1973 to 2012. They focused on rainfed crops, since they are highly sensitive to changes in temperature and extreme weather."We found that on average, over these cropland areas, things are getting warmer," said Mueller, also a researcher in the CSU College of Agricultural Sciences.The study showed that exposure to increased high temperatures for corn, wheat and rice was much less than it would have been if the crops were positioned where they were in the 1970s.CSU postdoctoral fellow and first author Lindsey Sloat said this does not mean there is an unlimited capacity for farmers to adapt to climate change by shifting where they grow crops."If you add new farmland, that comes with massive environmental consequences," she said. "Land use change in agriculture is one of the biggest drivers of biodiversity loss, with consequences for carbon storage. We can mitigate some of the effects of climate change by increasing irrigation, but there are also environmental costs on that front."Researchers also found that unlike the other crops, there has been a huge expansion in the production of soybeans, and that these crops are being grown in hotter areas around the world.Sloat said the research team will next delve into analyzing other climate variables, moving beyond temperature to consider how changes in a harvested area can alter exposure to other extreme climate conditions."Since this migration has been extensive enough in the past to substantially alter exposure to climate trends, we need to think about what our agricultural landscapes are going to look like in the future as warming increases," said Mueller.Co-authors on the paper include Steven Davis from the University of California, Irvine; James Gerber, Deepak Ray and Paul West from the University of Minnesota; and Frances Moore from the University of California, Davis.
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Agriculture & Food
| 2,020 |
March 5, 2020
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https://www.sciencedaily.com/releases/2020/03/200305203550.htm
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Food scientists slice time off salmonella identification process
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Researchers from Cornell University, the Mars Global Food Safety Center in Beijing, and the University of Georgia have developed a method for completing whole-genome sequencing to determine salmonella serotypes in just two hours and the whole identification process within eight hours.
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Determining salmonella's serotype makes it easier for food safety sleuths to find the source of bacterial contamination, which can occur in a wide range of foods, such as fruits, vegetables, nuts, meat, cereal, infant formula and pet food."As the food supply chain becomes ever more global and interconnected, the opportunity for food to become contaminated with salmonella increases," said lead author Silin Tang, senior research scientist in microbial risk management at the Mars Global Food Safety Center in China. "In the fast-moving world of food manufacturing, where rapid identification and response to salmonella contamination incidents is critical, developing a more efficient pathogen identification method is essential."Conventional serotyping has been at the core of public health monitoring of salmonella infections for a half-century, Tang said. But long turnaround times, high costs and complex sample preparations have led global food safety regulators, food authorities and public health agencies to change to whole-genome sequencing methods for pathogen subtyping.All 38 salmonella strains -- representing 34 serotypes -- assessed in this study were accurately predicted to the serotype level using whole-genome sequencing.This is important news for the food industry, as very few laboratories can conduct classical serotyping, said Martin Wiedmann, food safety professor and a Cornell Institute for Food Systems faculty fellow."In some countries," Wiedmann said, "it can take up to two days to even get the suspected salmonella to a certified lab."With whole genome sequencing, he said, the new state-of-the-art test relies on simple equipment. "For the food industry, processing plants are in the middle of nowhere," he said. "Now you can conduct testing in a lab that's close to the food processing plant."
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Agriculture & Food
| 2,020 |
March 5, 2020
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https://www.sciencedaily.com/releases/2020/03/200305135037.htm
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Corn productivity in real time: Satellites, field cameras, and farmers team up
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University of Illinois scientists, with help from members of the Illinois Corn Growers Association, have developed a new, scalable method for estimating crop productivity in real time. The research, published in
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"Our ultimate goal is to provide useful information to farmers, especially at the field level or sub-field level. Previously, most available satellite data had coarse spatial and/or temporal resolution, but here we take advantage of new satellite products to estimate leaf area index (LAI), a proxy for crop productivity and grain yield. And we know the satellite estimates are accurate because our ground measurements agree," says Hyungsuk Kimm, a doctoral student in the Department of Natural Resources and Environmental Sciences (NRES) at U of I and lead author on the study.Kimm and his colleagues used surface reflectance data, which measures light bouncing off the Earth, from two kinds of satellites to estimate LAI in agricultural fields. Both satellite datasets represent major improvements over older satellite technologies; they can "see" the Earth at a fine scale (3-meter or 30-meter resolution) and both return to the same spot above the planet on a daily basis. Since the satellites don't capture LAI directly, the research team developed two mathematical algorithms to convert surface reflectance into LAI.While developing the algorithms to estimate LAI, Kimm worked with Illinois farmers to set up cameras in 36 corn fields across the state, providing continuous ground-level monitoring. The images from the cameras provided detailed ground information to refine the satellite-derived estimates of LAI.The true test of the satellite estimates came from LAI data Kimm measured directly in the corn fields. Twice weekly during the 2017 growing season, he visited the fields with a specialized instrument and measured corn leaf area by hand.In the end, the satellite LAI estimates from the two algorithms strongly agreed with Kimm's "ground-truth" data from the fields. This result means the algorithms delivered highly accurate, reliable LAI information from space, and can be used to estimate LAI in fields anywhere in the world in real time."We are the first to develop scalable, high-temporal, high-resolution LAI data for farmers to use. These methods have been fully validated using an unprecedented camera network for farmland," says Kaiyu Guan, assistant professor in the Department of NRES and Blue Waters professor at the National Center for Supercomputing Applications. He is also principal investigator on the study.Having real-time LAI data could be instrumental for responsive management. For example, the satellite method could detect underperforming fields or segments of fields that could be corrected with targeted management practices such as nutrient management, pesticide application, or other strategies. Guan plans to make real-time data available to farmers in the near future."The new LAI technology developed by Dr. Guan's research team is an exciting advancement with potential to help farmers identify and respond to in-field problems faster and more effectively than ever before," says Laura Gentry, director of water quality research for the Illinois Corn Growers Association."More accurate measurements of LAI can help us to be more efficient, timely, and make decisions that will ultimately make us more profitable. The last few years have been especially difficult for farmers. We need technologies that help us allocate our limited time, money, and labor most wisely. Illinois Corn Growers Association is glad to partner with Dr. Guan's team, and our farmer members were happy to assist the researchers with access to their crops in validating the team's work. We're proud of the advancement this new technology represents and are excited to see how the Guan research team will use it to bring value directly to Illinois farmers," Gentry adds.
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Agriculture & Food
| 2,020 |
March 5, 2020
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https://www.sciencedaily.com/releases/2020/03/200305132208.htm
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Unexpected ways animals influence fires
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Animals eating plants might seem like an obvious way to suppress fire, and humans are already using the enormous appetites of goats, deer, and cows to reduce the fuel available for potential wildfires. But other animals such as birds, termites, and elephants can also double as ecosystem engineers, naturally reducing or enhancing the chances, spread, or severity of wildfires as they go about their day-to-day grass-chewing, track-making, or nest-building. Researchers in Australia describe these and more surprising activities in a Review published March 5 in the journal
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When it comes to grazing animals, it's important to consider which species of plants they are eating, and which are left behind. "A lot of the things that make a plant good to eat are the things that make it hard to burn," says first author Claire Foster, terrestrial conservation biologist and research fellow at Australian National University. "When you take out all the nutritious, palatable plants, those left over tend to be drier and more flammable."Studies have shown that removing large grazers like cattle or rhinoceros can increase wildfire temperature, as well as the size of individual fires and the total area burnt. But, it's important to note that these grazers are most effective as a fire management tool in grassy habitats like savanna; if domesticated grazers are used improperly, they can promote the growth of less tasty but more flammable plants. This can be a problem in alpine areas and in forests with mixed plant species, where selective feeding can increase the numbers of more fire-prone plants."It's very clear that when used strategically, and in the right ecosystems, mammals like goats and cattle can have strong fire-suppressive effects, but I've also seen many examples where they actually do the opposite and increase the risk of severe fires," Foster says.But there may be other, less obvious animals that could also be used in fire defense. "Some of the animals we don't necessarily think of are the insects that, by feeding on leaves, stimulate the production of defensive chemicals in the plants, changing the flammability of their leaves," says Foster. Other kinds of insects likely play a strong role in removing dead leaves from the forest floor and, in some cases, can even provide shelter for other animals from fire."One of the most amazing examples is from savanna ecosystems with termites," she says. "They create massive structures where a huge variety of other animals choose to live. These 'nutrient islands' attract large herbivores that preferentially graze around the termite mounds, making them less likely to burn and creating a safety zone during moderate-severity bushfires."Further, some animals can manage fire spread by changing the arrangement of plants or dead plant materials within their habitat. Similar to how you might rake your yard, malleefowl birds gather dead leaves into piles to incubate their eggs, helping clear the ground of leaf litter. Larger animals, like elephants, can trample down plants to form wide corridors between foliage. "Gaps in fuel can be really important for fire spread; animal tracks can act like mini roads, creating breaks that can cause extinguishment of the fire front," says Foster.All together, Foster, senior author and University of Western Australia wildlife biologist Leonie Valentine, and their co-authors illustrate that direct plant consumption is only one of several mechanisms that can influence fire behavior. "Our approach was to encourage readers to think about the more subtle and indirect ways that animals might be altering fuels and to help avoid risky assumptions when we plan strategies to reduce the risk of fire outbreaks," Foster says. "We also encourage readers to consider ways that changes in wildlife populations -- and not just grazers -- might influence patterns of fire."Next, Foster and her lab are investigating the relationship between forest insects and rates of leaf-litter breakdown within ecosystems as well as the effects of kangaroos and wallabies on the behavior of fire in Australian forests.This project was funded by an ARC Linkage Project, in collaboration with Parks Australia and the Department of Defence, as well as the Australian Government's National Environmental Science Program, through the Threatened Species Recovery Hub.
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Agriculture & Food
| 2,020 |
March 5, 2020
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https://www.sciencedaily.com/releases/2020/03/200305132055.htm
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Genome editing strategy could improve rice, other crops
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Scientists at UC Davis have used CRISPR technology to genetically engineer rice with high levels of beta-carotene, the precursor of vitamin A. The technique they used provides a promising strategy for genetically improving rice and other crops. The study was published today in the journal
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Rice is a staple food crop for more than half the world's population. Golden Rice, a genetically engineered rice with high levels of beta-carotene, has been approved for consumption in more than five countries, including the Philippines, where vitamin A deficiency in children is widespread. Because of the social impact of Golden Rice, the researchers chose the high beta-carotene trait as an example.Conventional plant genetic engineering uses a bacterium or a particle gun to transfer genes encoding desired traits into the plant genome. In this case, researchers would use a bacterium to take beta-carotene producing genes and transfer them into the rice genome. But those transgenes can integrate into random positions in the genome, which can result in reduced yields."Instead, we used CRISPR to precisely target those genes onto genomic safe harbors, or chromosomal regions that we know won't cause any adverse effects on the host organism," said first author Oliver Dong, a postdoctoral scholar in the UC Davis Department of Plant Pathology and Genome Center.In addition, the researchers were able to precisely insert a very large fragment of DNA that does not contain marker genes. By contrast, conventional genetic engineering relies on the inclusion of marker genes in the inserted DNA fragment. These marker genes are retained when the plant is bred over generations, which can often trigger public concern and stringent regulations of the transgenic products before their entrance to the marketplace."Scientists have done targeted insertions before and without marker genes, but we haven't been able to do it with such big fragments of DNA," said Dong. "The larger the fragment of DNA, the more biological function or complex traits we can provide the plants."Dong said this opens up the possibility that genes controlling multiple desirable traits, such as having high levels of beta-carotene as well as being disease-resistant or drought-tolerant, can be clustered at a single position within the genome. This can greatly reduce subsequent breeding efforts.
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Agriculture & Food
| 2,020 |
March 5, 2020
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https://www.sciencedaily.com/releases/2020/03/200305002838.htm
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Flower faithful native bee makes a reliable pollinator
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Entomologists at UC Riverside have documented that a species of native sweat bee widespread throughout North and South America has a daily routine that makes it a promising pollinator.
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Because the bee can thrive in environments that have been highly modified by humans, such as cities and agricultural areas, it could become a suitable supplement to honeybees, which are expensive for farmers to rent and threatened by pesticides and climate change.Sweat bees are not as famous as their prolific cousin, the European honeybee, but are common in natural, urban, and agricultural areas in North America. Sweat bees, along with other native bees like bumble bees, are valuable pollinators of many wildflowers and cultivated crop plants, yet often do not receive the level of public attention that honeybees do.In a paper published in the journal To explore this species' daily routine, Cecala captured sweat bees while feeding on flowers in several commercial plant nurseries across Southern California. Nurseries grow many different species of plants in close proximity to one another, so they are useful for studying bees' foraging choices. He marked the bees with different colored dots of non-toxic paint to track which plants they were visiting.He returned the next day and caught almost 52% of the marked bees again. Cecala repeated this experiment four times in summer and four times in autumn and recaptured around 50% each time. Virtually all -- 96% -- were found on the same plant species as on the first day, indicating that most individual bees fed on the same plant species day-to-day. The findings suggest it is common for individual bees to make consistent choices about what to forage on across days."These results are encouraging given that plant nurseries are, relatively speaking, artificial human-made habitats. You would expect really intense agricultural and urban areas to be pretty devoid of biodiversity but these native bees are flying around and visiting the plants and using them as pollen and nectar resources," Cecala said.The study also documented a 45% higher probability of recapturing the bees on California native plant species than on plant species exotic to California. This varied somewhat by season. Recapture rates were higher on the native plants in the summer, suggesting seasonal differences in how the bees forage. While this suggests native plants are more valuable to these bees, many individuals still showed fidelity to non-native plants.Much remains to be learned about Even though the study took place inside plant nurseries, its findings have implications for commercial crop pollination on farms. While farmers must pay to rent commercial honeybee hives, native bees like sweat bees provide pollination services free of charge."Honeybees, which are larger, forage much farther," Rankin added. "Even if you put honeybees in your field there's nothing to say they're not actually going two farms over, whereas these sweat bees forage repeatedly on plants right around the area where they live.""These wild bees are pretty good, consistent pollinators," Cecala said. "If you have these sweat bees in the area, it's in your best interest to conserve them in whatever way you can, because they are probably visiting crops each day, not just passing through."This study reinforces that certain plants publicly available at nurseries can serve as dependable resources for native bees. By planting a variety of different flowers around their homes, and ensuring they are free of insecticides, anyone can help these native bees.
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Agriculture & Food
| 2,020 |
March 4, 2020
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https://www.sciencedaily.com/releases/2020/03/200304141520.htm
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Honeybee dance dialects
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After more than 70 years, a great mystery of zoology has been solved: Honeybees actually use different dance dialects in their waggle dance. Which dialect has developed during evolution is related to the radius of action in which they collect food around the hive.
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This is reported by research teams from the Biocenter of Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, and the National Centre for Biological Sciences (NCBS) in Bangalore, India, in the journal That honey bees might have dance dialects was first proposed in the 1940s by nobel laureate Karl von Frisch and his student Martin Lindauer. Later experiments, however, raised doubts about the existence of the dialects. The new results now prove that Frisch and Lindauer were right. The two pioneers of behavioural research were also right with their explanation why the dance dialects exist at all.The dance language of the honeybees is a unique form of symbolic communication in the animal kingdom. For example, when a bee has discovered a blossoming cherry tree, it returns to the hive. There it informs the other bees with a dance about the direction in which the food source is located and how far away it is.Part of the dance is the so-called waggle run, in which the bees energetically shake their abdomen. The direction of the waggle run on the honeycomb communicates the direction of the destination in relation to the position of the sun while the duration of the wagging indicates the distance."As the distance of the food source from the nest increases, the duration of the wagging increases in a linear fashion," explains JMU PhD student Patrick Kohl, first author of the publication. However, this increase is different for different bee species. This was shown in experiments carried out by the research team in southern India.There, three bee species with different radii of action were studied. The eastern honeybees (Apis cerana) fly up to about one kilometre away from the nest. The dwarf honeybees (Apis florea) fly up to 2.5 kilometres, the giant honeybees (Apis dorsata) about three kilometres.The opposite relationships apply for the increase in the duration of the wagging. For example, if a food source is 800 meters away, an eastern honeybee will have a much longer wagging than a dwarf honeybee, and the latter will have a longer wagging than the giant honeybee. In order to communicate an identical distance to the food, each species uses its own dance dialect."We also saw this when we compared our results with published data from other research groups," says Patrick Kohl. The correlation between foraging range and dance dialect was corroborated when looking at honeybee species native to England, Botswana, and Japan.Why did JMU researchers go to South India in the first place? "India has the advantage that three honeybee species live in the same area, so that their dance dialects can be easily compared," said Kohl. "We also have very good contacts with researchers at NCBS, a top research address in South Asia."The results also confirm what von Frisch and Lindauer had suspected about the meaning of the dance dialects. These are evolutionary adaptations to the honeybee species' typical foraging distances. Honeybees, for example, which regularly fly long distances, cannot afford to communicate these distances in the hive with very long waggle runs: On the crowded dance floor in the hive, other bees would have difficulties following such "marathon waggings."The scientists' conclusion: The dance dialects of the bees are an excellent example of how complex behaviours can be tuned as an evolutionary adaptation to the environment.
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Agriculture & Food
| 2,020 |
March 3, 2020
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https://www.sciencedaily.com/releases/2020/03/200303204458.htm
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Pesticides impair baby bee brain development
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Imperial College London researchers used micro-CT scanning technology to reveal how specific parts of bumblebee brains grew abnormally when exposed to pesticides during their larval phase.
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Most previous studies have tested the effects of pesticide exposure on adult bees because these individuals directly collect pesticide-contaminated nectar and pollen. However, this study shows that baby bees can also feel the effects of the contaminated food brought back to the colony, making them poorer at performing tasks later in life.Lead researcher Dr Richard Gill, from the Department of Life Sciences at Imperial, said: "Bee colonies act as superorganisms, so when any toxins enter the colony, these have the potential to cause problems with the development of the baby bees within it."Worryingly in this case, when young bees are fed on pesticide-contaminated food, this caused parts of the brain to grow less, leading to older adult bees possessing smaller and functionally impaired brains; an effect that appeared to be permanent and irreversible."These findings reveal how colonies can be impacted by pesticides weeks after exposure, as their young grow into adults that may not be able to forage for food properly. Our work highlights the need for guidelines on pesticide usage to consider this route of exposure."The team, who published their results today in The colony was provided with a nectar substitute spiked with a class of pesticides called neonicotinoids, some of which are restricted within the EU but used widely across the globe. Once the young emerged as adults from their pupae, their learning ability was tested after three days and after 12 days, and some went on to have their brains imaged using micro-CT technology at the Natural History Museum.These results were compared with young from colonies that were fed no pesticides, and those that were fed pesticides only once they had emerged as an adult.Bees that were fed pesticides when they were developing as larvae showed significantly impaired learning ability compared to those that were not. The researchers tested this by seeing if the bees could learn to associate a smell with a food reward, scoring how many times out of ten each successfully performed the task.The researchers scanned the brains of close to 100 bees from the different colonies and found that those who had been exposed to pesticides also had a smaller volume of an important part of the insect brain, known as the mushroom body.The mushroom body is known to be involved in learning ability in insects, and poor performance on the learning task correlated with smaller mushroom body volume. This supports the suggestion that smaller mushroom body volume associated with pesticide exposure is the cause of the bees' poor performance.Bees that were exposed to pesticides during larval development but not as adults showed similar learning impairment and mushroom body volume reduction when tested at both three and 12 days as an adult. This suggests that at least within the unexposed nine days they were adults, the effects of larval exposure could not be overcome, pointing to a potentially permanent effect.Lead author of the study Dr Dylan Smith, from the Department of Life Sciences at Imperial, said: "There has been growing evidence that pesticides can build up inside bee colonies. Our study reveals the risks to individuals being reared in such an environment, and that a colony's future workforce can be affected weeks after they are first exposed."Bees' direct exposure to pesticides through residues on flowers should not be the only consideration when determining potential harm to the colony. The amount of pesticide residue present inside colonies following exposure appears to be an important measure for assessing the impact on a colony's health in the future."The team previously pioneered the use of micro-CT to scan bee brains, and with this study have shown how the technology can be used to test ecologically applied questions that require measuring tiny but important differences in size and shape.
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Agriculture & Food
| 2,020 |
March 3, 2020
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https://www.sciencedaily.com/releases/2020/03/200303113234.htm
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How millets sustained Mongolia's empires
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The historic economies of Mongolia are among the least understood of any region in the world. The region's persistent, extreme winds whisk away signs of human activity and prevent the buildup of sediment which archaeologists rely on to preserve the past. Today crop cultivation comprises only a small percent of Mongolia's food production, and many scholars have argued that Mongolia presents a unique example of dense human populations and hierarchical political systems forming without intensive farming or stockpiling grains.
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The current study, led by Dr. Shevan Wilkin of the Max Planck Institute for the Science of Human History provides, for the first time, a detailed glimpse into the diets and lives of ancient Mongolians, underscoring the importance of millets during the formation of the earliest empires on the steppe.Collaborating with archaeologists from the National University of Mongolia and the Institute of Archaeology in Ulaanbaatar, Dr. Wilkin and her colleagues from the MPI SHH sampled portions of teeth and rib bones from 137 previously excavated individuals. The skeletal fragments were brought back to the ancient isotope lab in Jena, Germany, where researchers extracted bone collagen and dental enamel to examine the ratios of stable nitrogen and carbon isotopes within. With these ratios in hand, scientists were able to reconstruct the diets of people who lived, ate, and died hundreds to thousands of years ago.Researchers tracked the trends in diet through the millennia, creating a "dietscape" which clearly showed significant differences between the diets of Bronze Age peoples and those who lived during the Xiongnu and Mongol Empires. A typical Bronze Age Mongolian diet was based on milk and meat, and was likely supplemented with small amounts of naturally available plants. Later, during the Xiongnu Empire, human populations displayed a larger range of carbon values, showing that some people remained on the diet common in the Bronze Age, but that many others consumed a high amount of millet-based foods. Interestingly, those living near the imperial heartlands appear to have been consuming more millet-based foods than those further afield, which suggests imperial support for agricultural efforts in the more central political regions. The study also shows an increase in grain consumption and increasing dietary diversity through time, leading up to the well-known Mongolian Empire of the Khans.The new discoveries presented in this paper show that the development of the earliest empires in Mongolia, like in other parts of the world, was tied to a diverse economy that included the local or regional production of grain. Dr. Bryan K. Miller, a co-author who studies the historical and archaeological records of Inner Asian empires, remarks that "these regimes were like most empires, in that they directed intricate political networks and sought to amass a stable surplus -- in this case a primarily pastoral one that was augmented by other resources like millet.""In this regard," Dr. Miller adds, "this study brings us one step closer to understanding the cultural processes that led humanity into the modern world."The view that everyone in Mongolian history was a nomadic herder has skewed discussions concerning social development in this part of the world. Dr. Wilkin notes that "setting aside our preconceived ideas of what prehistory looked like and examining the archaeological record with modern scientific approaches is forcing us to rewrite entire sections of humanity's past." Dr. Spengler, the director of the archaeobotany labs at the MPI SHH, emphasizes the importance of this discovery, noting that "this study pulls the veil of myth and lore off of the real people who lived in Mongolia millennia ago and lets us peak into their lives."
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Agriculture & Food
| 2,020 |
March 2, 2020
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https://www.sciencedaily.com/releases/2020/03/200302113422.htm
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How quickly do flower strips in cities help the local bees?
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Insects rely on a mix of floral resources for survival. Populations of bees, butterflies, and flies are currently rapidly decreasing due to the loss of flower-rich meadows. In order to deal with the widespread loss of fauna, the European Union supports "greening" measures, for example, the creation of flower strips.
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A group of scientists from the University of Munich, led by Prof. Susanne S. Renner, has conducted the first quantitative assessment of the speed and distance over which urban flower strips attract wild bees, and published the results of the study in the open-access Flower strips are human-made patches of flowering plants that provide resources for flower-visiting insects and insect- and seed-feeding birds. Previous experiments have proved their conservation value for enhancing biodiversity in agricultural landscapes.The success of flower strips in maintaining populations of solitary bees depends on the floristic composition, distance from suitable nesting sites, and distance from other habitats maintaining stable populations of bees. To study the attractiveness of the flower strips in urban landscapes, the scientists used an experimental set-up of nine 1,000 sq. meters flower strips recently established in Munich by a local bird conservation agency."We identified and counted the bees visiting flowers on each strip and then related these numbers to the total diversity of Munich's bee fauna and to the diversity at different distances from the strips. Our expectation was that newly planted flower strips would attract a small subset of mostly generalist, non-threatened species and that oligolectic species (species using pollen from a taxonomically restricted set of plants) would be underrepresented compared to the city's overall species pool," shared Prof. Susanne S. Renner.Bees need time to discover new habitats, but the analysis showed that the city's wild bees managed to do that in just one year so that the one-year-old flower strips attracted one-third of the 232 species recorded in Munich between 1997 and 2017.Surprisingly, the flower strips attracted a random subset of Munich's bee species in terms of pollen specialization. At the same time, as expected, the first-year flower-strip visitors mostly belonged to common, non-threatened species.The results of the study support that flower strip plantings in cities provide extra support for pollinators and act as an effective conservation measure. The authors therefore strongly recommend the flower strip networks implemented in the upcoming Common Agricultural Policy (CAP) reform in the European Union.
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Agriculture & Food
| 2,020 |
March 2, 2020
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https://www.sciencedaily.com/releases/2020/03/200302113408.htm
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How three genes rule plant symbioses
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For billions of years life on Earth was restricted to aquatic environments, the oceans, seas, rivers and lakes. Then 450 million years ago the first plants colonized land, evolving in the process multiple types of beneficial relationships with microbes in the soil.
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These relationships, known as symbioses, allow plants to access additional nutrients. The most intimate among them are intracellular symbioses that result in the accommodation of microbes inside plant cells.A study published in It is hypothesised that the colonization of land by plants was made possible through a type of symbiosis that plants form with a group of fungi called mycorrhizal fungi. Even today 80% of plants we find on land can form this mycorrhizal symbiosis. Plants have also evolved the ability to engage in intracellular symbiosis with a large diversity of other microbes.Over the past two decades, studies on mycorrhizal symbiosis and another type of symbiosis, formed by legumes such as peas and beans with soil bacteria, have allowed the identification of a dozen plant genes that are required for the recognition of beneficial microbes and their accommodation inside plant cells. By contrast, other types of intracellular symbioses have been poorly studied.To address this, the team compared the genomes of nearly 400 plant species to understand what is unique to those that can form intracellular symbioses. Surprisingly, they discovered that three genes are shared exclusively by plants forming intracellular symbiosis and lost in plants unable to form this type of beneficial relationship."Our study demonstrates that diverse types of intracellular symbioses that plants form with different symbiotic partners are built on top of a conserved genetic program." said Dr Guru Radhakrishnan, lead author of the study and a BBSRC Discovery Fellow at the John Innes Centre.The research, led by Dr Radhakrishnan in the UK and Dr Pierre-Marc Delaux in France, was conducted as part of the Engineering Nitrogen Symbiosis for Africa (ENSA) project sponsored by the Bill & Melinda Gates foundation.ENSA is an international collaboration aiming at transferring naturally occurring symbioses to cereal crops to limit the use of chemical fertilizers and to improve yield in small-holder farms of sub-Saharan Africa where access to these fertilizers is limited."By demonstrating that different plant symbioses share a common genetic basis, our ambitious goal has become more realistic," says Dr Radhakrishnan.
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Agriculture & Food
| 2,020 |
March 2, 2020
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https://www.sciencedaily.com/releases/2020/03/200302113401.htm
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Fallowing cattle-feed farmland simplest way to alleviate western U.S. water shortage
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All over the world, the rate at which humans consume fresh water is now approaching or surpassing the rate at which water sources are being naturally replenished, creating water shortages for people and ecosystems. In the western US, water shortages are becoming more frequent and more severe, and are putting many species of fish inhabiting western rivers at risk -- but the scarcity of water is also risking the growth of cities in the region like Los Angeles and Phoenix.
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An important new study published this week in Study co-author and principal investigator Ben Ruddell, who is also director of NAU's School of Informatics, Computing, and Cyber Systems, leads the FEWSION project, a multi-institutional team effort launched in 2016 and funded through the National Science Foundation (NSF), to assess the nation's food, energy and water systems. The broader FEWSION research team contributed the data-intensive maps it has produced of these coupled human-natural systems. NAU assistant research professor Richard Rushforth, the lead data scientist on FEWSION, also co-authored the study.The study set out to assess river flow depletion across the US, identify the factors driving this depletion and evaluate options to reduce vulnerability to water shortages. The researchers estimate that two-thirds of the cattle feed being irrigated from western US rivers ends up as beef products, with the remainder going to dairy products."The groundbreaking maps produced by FEWSION made it possible to link river depletion through the supply chain to irrigated alfalfa and hay and to beef and dairy production, then to urban consumers of beef and dairy in each city and county in the US," Ruddell said.According to the study, the team's findings "led to closer examination of the water use and ecological impacts associated with irrigation of cattle-feed crops. We pinpointed locations where these crops were being grown and modelled their associated depletion of river flow in local sub-watersheds. We then conducted an international supply-chain analysis to identify the locations where cattle-feed crops are transported and where the resulting beef products are consumed, thereby specifically linking end consumers of beef to effects on rivers. We subsequently explored the benefits and consequences of reduced feed-crop production and beef consumption through the lenses of water security, river ecosystem health, food security and agricultural economies.""We're using a lot of water to grow the cows that are the source of our burgers, steaks and milk," Ruddell points out. "In the Colorado River basin, that cattle feed water use is nearly three times greater than all the water used for urban, industrial and electrical power purposes combined."Along with the study's lead author and FEWSION contributor Brian Richter, Ruddell was surprised by some of their findings."I can hardly believe that such a large fraction of our western water problems are linked to irrigation of cattle feed, or that such a large fraction of our western water problems could be fixed with a single prescription -- fallowing. It's rare that science clearly finds a 'silver bullet' that solves such a big problem so well, and so affordably," Ruddell said."Although the idea for this study of the US food energy and water system was proposed as part of the FEWSION project," he noted, "the roots of the ideas go back decades and involve many of the pioneers of river science and environmental sustainability -- including Brian Richter, who is one of the founders of the science of river management for environmental flows. It takes a long time, generous research funding, and a broad team with diverse interdisciplinary skills for synthetic ideas like this to become a reality."Scientists from 12 universities worldwide collaborated on the study, including Columbia University, Baylor University, the National University of Singapore, Nanjing Audit University and the University of Twente.Ultimately, they conclude, "Water security and river health in the western US will depend on the willingness of urban and rural water users to collaborate in design of demand-management strategies, the ability of political leaders to secure funding to implement those strategies and the willingness of beef and dairy consumers to reduce their consumption or select products that do not depend on irrigated cattle-feed crops."My favorite food is cheeseburgers!" Ruddell admitted. "Individual choice, in addition to collective politics and policy, are important here. We need to be willing to pay a little more for more sustainable beef and dairy products, and we must strongly support politicians and policies that are willing to invest in solutions to the western water problem -- including infrastructure, environmental flows and smart economic solutions like fallowing. Act with your votes and with your dollars. This is a problem we can afford to solve!"FEWSION was funded in 2016 by a grant from the Innovations at the Nexus of Food, Energy and Water Systems program (#INFEWS ACI-1639529), which is funded by the NSF and the US Department of Agriculture.
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Agriculture & Food
| 2,020 |
February 28, 2020
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https://www.sciencedaily.com/releases/2020/02/200228105224.htm
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Cat food mystery foils diet study
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A study that set out to measure how much wildlife domestic cats eat to supplement the food they are given by their owners was unsuccessful due to an unexpectedly high variability in cat food ingredients. This accidental discovery suggests that some cat food manufacturers regularly change ingredient composition, even within the same flavors of cat food.
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Feral cats are responsible for several native wildlife declines, like the Key Largo woodrat, but the impact of pet cats on urban wildlife isn't well understood. This inspired a collaborative study led by researchers at North Carolina State University to directly measure how often pet cats eat outside of their food bowls.A common way to understand the composition of animal diets is to collect samples of fur, nails, or blood from an animal and analyze its carbon and nitrogen isotopes. All organic materials contain isotopes of elements that get locked into body tissues, following the basic principle that you are what you eat. For example, the ratios of nitrogen isotopes present in carnivores are dependably distinct from those of plant eaters. Similarly, researchers can distinguish the types of plants that an animal eats by measuring the ratio of carbon isotopes.For this study, researchers collected isotopes from things a cat might eat, including different brands and flavors of cat foods. They predicted cats that only ate from their food bowls would have an identical isotopic match to the food, while differences between cat and pet food would indicate a cat supplementing its diet with wild prey."We really thought this was going to be an ideal application of the isotope methodology," says Roland Kays, a co-author of the study and scientist at NC State and the NC Museum of Natural Sciences. "Usually these studies are complicated by the variety of food a wild animal eats, but here we had the exact pet food people were giving their cats."This assumes that cat food producers use consistent types and amounts of ingredients. As it turns out, that is not the case.The carbon and nitrogen isotopes in cat foods varied widely -- even between foods that were the same flavor and from the same brand. The only clear relationship found was that the least expensive cat foods had higher carbon values, indicating a strong presence of corn product in inexpensive cat food. In addition, pet foods sampled from the United Kingdom had lower carbon values, suggesting less input from corn products."This isn't what we aimed to study, but it is important in as much as there are hundreds of millions of cats (perhaps more) on Earth," says Rob Dunn, co-author of the study and a professor in NC State's Department of Applied Ecology. "The diets of cats, dogs and domestic animals have enormous consequences for global sustainability, cat health and much else. But they are very non-transparent. In short, at the end of this study we are still ignorant about why some cats kill more wildlife than others, and we have also found we are ignorant about something else, the shifting dynamics of 'Big Pet Food.'"The paper, "High variability within pet foods prevents the identification of native species in pet cats' diets using isotopic evaluation," is published in the journal
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Agriculture & Food
| 2,020 |
February 28, 2020
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https://www.sciencedaily.com/releases/2020/02/200228105203.htm
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The enemy within: How a killer hijacked one of nature's oldest relationships
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Researchers have discovered how a notorious pathogen may have hijacked one of nature's most enduring mutual relationships.
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The work sheds new light on a long-standing enigma about why plants possess genes that appear to be detrimental to their well-being.It's long been known that the Mildew Locus O (MLO) gene causes the majority of major crops to be susceptible to the fungal leaf pathogen powdery mildew. Loss of the gene causes durable and robust resistance to the pathogen.But if this gene is disadvantageous to the host, why has it been conserved throughout evolutionary history? Does this susceptibility factor also fulfil some other beneficial role?In a joint project between the John Innes Centre and the Shanghai Institute of Plant Physiology and Ecology, scientists found that the MLO gene needed by the powdery mildew pathogens is also used by symbiotic mycorrhizal fungi that help plants obtain nutrients from the soil.Mycorrhizal fungi are beneficial soil microorganisms that establish symbiotic interactions in plant roots and contribute to nutrient uptake. Powdery mildews are serious leaf fungal pathogens that infect many different plant genera and cause significant crop losses in agriculture.Importantly, the MLO gene and mycorrhizal symbiosis appeared very early in the evolution of land plants, millions of years before the occurrence of powdery mildew fungi.In this study, experiments showed that mycorrhizal colonisation was reduced in mutant plants of barley, wheat and Medicago truncatula which did not express the MLO gene. This was accompanied by a pronounced decrease in the expression of many key genes required for accommodation of arbuscular mycorrhizal fungi inside plant cells. The findings suggest the primary role for MLO in flowering plants is in colonisation by the arbuscular mycorrhizal fungi, and that this role has been appropriated by powdery mildew.The MLO gene is present in a wide variety of plants including important crops such as rice, wheat and legumes. The results have important implications for crop improvement and for sustainable agriculture to enhance beneficial mycorrhizal interactions while reducing losses from disease."The MLO gene has been widely studied for its role in powdery mildew resistance, although its ancestral role has remained elusive," explains first author Dr Catherine Jacott."Since mycorrhizal fungi and powdery mildew respectively infect root and shoot, it may be possible to generate cereals that could fully support mycorrhiza while remaining non-hosts for powdery mildew."The study: Mildew Locus O facilitates colonization by arbuscular mycorrhiza in angiosperms, appears in
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Agriculture & Food
| 2,020 |
February 28, 2020
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https://www.sciencedaily.com/releases/2020/02/200228102238.htm
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Discovering what makes durian fruit stink
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Researchers at the Leibniz-Institute for Food Systems Biology at the Technical University of Munich (Leibniz-LSB@TUM) have confirmed the presence of the rare amino acid ethionine in a plant -- or more precisely, in the fruit of the durian tree. Despite its pungent odor, durian is very popular in Southeast Asia. As the team of scientists has shown, the amino acid plays a key role in the formation of the characteristic durian odor.
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The pulp of a ripe durian emits an unusually potent and very persistent smell that is reminiscent of rotten onions. That is why the fruit has been banned on local public transportation in Singapore and at numerous hotels in Thailand. Nevertheless, different varieties of durian are highly valued in many Asian countries. Durian pulp has a high nutritional value, a distinctly sweet taste, and a pleasantly creamy consistency.Previous research conducted at the Leibniz-LSB@TUM had already shown that the fruit's stench is essentially due to the odorant ethanethiol and its derivatives. However, the biochemical pathway by which the plant produces ethanethiol remained unclear. As Nadine S. Fischer and Martin Steinhaus of the Leibniz-LSB@TUM have now demonstrated for the first time in their new study, ethionine is the precursor of the foul-smelling substance."Our findings suggest that as the fruit ripens, a plant-specific enzyme releases the odorant from ethionine," says lead author Nadine Fischer. "This is consistent with our observation that during fruit ripening not only the ethionine concentration in the pulp increases, but also at the same time that of the ethanethiol. The latter explains why a ripe durian emits an extremely strong smell.""Knowing exactly how much ethionine the durian fruit contains is interesting not only because of its significance for the odor," says principle investigator Martin Steinhaus. The food chemist adds that animal tests and cell culture studies have verified that the amino acid is not harmless. Rats that incorporated high doses of the amino acid together with their food developed liver damage and cancer of the liver. A newer study, however, suggests that low concentrations of ethionine may even have positive immunomodulatory effects."This raises the question of whether eating the fruit entails health risks," says Steinhaus. "Further studies certainly need to be conducted." The expert reassures us, however, by noting that "in order to consume a comparable dose of ethionine that had toxic effects in animal tests, a person weighing 70 kilograms would in one day have to eat 580 kilograms of fruit pulp of the Krathum variety which is especially rich in ethionine."
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Agriculture & Food
| 2,020 |
February 27, 2020
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https://www.sciencedaily.com/releases/2020/02/200227144232.htm
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Universally positive effect of cover crops on soil microbiome
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Only a fraction of conventional row crop farmers grow cover crops after harvest, but a new global analysis from the University of Illinois shows the practice can boost soil microbial abundance by 27%.
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The result adds to cover crops' reputation for nitrogen loss reduction, weed suppression, erosion control, and more. Although soil microbial abundance is less easily observed, it is a hugely important metric in estimating soil health."A lot of ecological services are done by the soil microbiome, including nutrient cycling. It's really important to understand how it functions and how agriculture can form a healthier soil microbiome," says Nakian Kim, doctoral student in the Department of Crop Sciences at the University of Illinois and lead author on a new paper in Other studies have shown benefits of cover cropping on the soil microbial community, but most of them have been one-offs influenced by specific site conditions, unique seasonal effects, idiosyncratic management regimes, and the researchers' chosen analysis methods. Kim's work is different in that he looked for universal patterns among dozens of these one-off studies."Our analysis shows that across 60 field studies, there was a consistent 27% increase in microbial abundance in fields with cover crops versus no cover crops. It's across all these studies from around the world," says Maria Villamil, associate professor in crop sciences and co-author on the paper.The research team performed a search of the existing studies on cover crops, and wound up with some 985 scientific articles. Of these, they only kept studies that directly compared cover crops and bare fallow soils, and omitted studies conducted in greenhouses or that treated crop residues as cover crops. They also ensured that the studies were statistically sound, with reasonably large sample sizes. In the end, they mined and reanalyzed data from 60 studies reporting on 13 soil microbial parameters."That's why the criteria of selection had to be so strict. We wanted to compare studies that were solid, and with enough replications that we could make valid claims about global patterns," Villamil says.The research team divided the 13 microbial parameters into three categories: microbial abundance, activity, and diversity. Microbial abundance wasn't the only category to show a significant increase with cover cropping compared to bare fallow soils. Microbial activity was also up 22%, and diversity increased 2.5%."All the categories are important, but especially diversity, because a diverse microbiome is more resilient. Considering the close linkage between microbial diversity and the provision of ecosystem services, small impacts could go a long way to increase sustainability. In that sense, I think the cover crops are really helping," Kim says.The researchers were also able to tease out several factors that layered on top of the main effect of cover crops. For example, how did climate, cover crop termination method, or tillage regime affect the ability of the cover crops to benefit the soil microbial community?Kim says the use of burndown herbicides as a cover crop termination method had a strong moderating effect on the microbial community. "The results were very interesting. With chemical termination, the effect sizes were consistently smaller compared to mechanical termination. In other words, the benefits from the cover crops are diminished somehow from the herbicides. I think that's one big takeaway."Tillage also made a difference, according to Kim. He expected conventional tillage to reduce the effect of cover crops on the soil microbes, but instead, conservation tillage did that. "My guess is that because conservation tillage included not tilling at all, that allowed weeds to grow on the land. The weeds could have mimicked what the cover crops do. So the difference between the control treatment and the cover crop may decrease because of the weeds."Because their effects were indirect, these secondary factors need more research before real claims can be made. Villamil's research team already has studies in the works to get more definitive answers. But in the meantime, she's heartened by the results of the analysis as a whole."For me, it was surprising to see the consistent, positive effect of cover crops -- surprising but good. Finally! I've been researching cover crops in our typical corn-soybean rotations in Illinois since 2001, yet in these high-fertility environments, it has proven difficult to show any effects beyond cereal and annual rye capturing nitrogen (weather permitting). Changes in chemical and physical properties related to cover crop use are difficult to see," Villamil says. "But the microbiome, that's where it's at. That's how everything is related. Thanks to this work, I have something to look forward to when I put in cover crops, and have generated many more questions in need of research."
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Agriculture & Food
| 2,020 |
February 27, 2020
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https://www.sciencedaily.com/releases/2020/02/200227114450.htm
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Anthropogenic seed dispersal: Rethinking the origins of plant domestication
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The plants we consume for food have changed drastically in the 10,000 years since humans began practicing agriculture, but hominids have been intensively interacting with the plants and animals around them since before the dawn of our species. As humans became aware of the ability to modify crops through selective breeding, the evolution of new traits in plants greatly increased. However, plants have been evolving in response to human selective pressures since long before people began consciously altering them through breeding.
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In a new study published in Many of the earliest traits of domestication in plants are similar across different crop species, a phenomenon evolutionary biologists refer to as parallel evolution. For example, in all large-seeded grass crops -- e.g. wheat, barley, rice, oats -- the first trait of domestication is a toughening of the rachis (the individual stem that holds a cereal grain to the ear). Likewise, in all large-seeded legumes, such as peas, lentils, fava beans, and kidney beans, the earliest trait of domestication is a non-shattering pod.Archaeobotanists studying early plant domestication agree that the evolution of tougher rachises in cereal crops was a result of humans using sickles to harvest grains. During a harvest, the specimens with the most brittle rachises lost their seeds, whereas the plants with tougher rachises benefited from having their seeds protected and saved for the following year. Humans then cleared away competitive plants (weeding), tilled soil, sowed seeds, and maintained the crops until the next harvest. We can assume that the same process occurred for legumes.For nearly a century, scholars have been aware of the fact that this parallel evolution was the result of similar selective pressures from people in different centers of domestication around the world, leading to what many researchers call "domestication syndrome." In the simplest biological sense, Spengler suggests, humans provide better seed-dispersal services for food crops than those plants would have had in the wild, causing them to evolve traits that facilitated agriculture and improved their own chances of reproduction.Archaeobotanists have studied seed-dispersal traits in the wild relatives of cereal and legume crops, but few have discussed how the wild relatives of other crops dispersed their seeds. In this manuscript, Spengler steps away from the heavy focus on these few plants and looks at the wild seed-dispersal processes in other crops.Spengler notes that before the last Ice Age, megafaunal mammals, including humans, were key for the evolution of larger fruits in the wild. While some plants have mechanical methods of seed dispersal, the most common way plants spread their seeds is by recruiting animals to do it for them. Bright red cherries, for example, have evolved to entice birds with red-green color vision. The birds consume the sugary fruit, then fly to a new area and deposit the seed from the cherry. Larger fruits, however, require larger animals to distribute them, meaning the progenitor plants for most of the fruits in our produce markets today evolved to be spread by large mammals. Paleontologists have previously noted the parallel evolution of larger fruits to entice larger animals in many unrelated plant families, a process that Spengler reveals to be mirrored in the evolution of crops cultivated by humans.Spengler also theorizes that megafaunal mammals may have been key to the dispersal of seeds in the progenitors of small-seeded grains, such as quinoa, millets, and buckwheat. With smooth, hard-shelled seeds that grow at the top of the plant, no secondary defensive compounds or thorns, and a rapid rate of growth, the foliage of these plants are the perfect food for grazing animals. The small size of these wild seeds may have been an evolutionary adaptation that allowed them to pass successfully through the digestive systems of hooved mammals, which often only allow seeds smaller than 2mm to pass. Conceptualizing domestication as seed-dispersal based evolution, as Spengler proposes, explains why the first traits of domestication in all of the small-seeded annual crops were thinning of the seed coat, an increase in seed size, and breaking of dormancy -- a reversal of the traits that allowed for seed dispersal by grazing mammals. The domestication process severed the mutualistic ties these plants had with their wild seed dispersers and made them dependent upon humans for dispersal.During the Early and Mid-Holocene, plants in specific locations around the world started to evolve new traits in response to human cultivation practices. As human populations increased in size and became more concentrated, the selective pressures that people placed on these plants increased. In the wild, plants often evolve mutualistic relationships in response to heavy herbivory pressures. The same evolutionary responses, Spengler argues, can be seen in farmers' fields during the early steps towards domestication, with plants developing traits to better use humans as seed dispersers."Humans are the best seed dispersers that have ever existed, dispersing plant species all over the world," Spengler says. "We are currently removing all competitive plant species across the Amazon to spread soybean seeds -- a plant that originally evolved traits for a mutualistic relationship with humans in East Asia. Likewise, most of the prairies of the American Midwest have been removed in order to grow maize, a crop that evolved to recruit humans in tropical southern Mexico. Humans are powerful seed dispersers and plants will readily evolve new traits to spread their seeds and colonize new areas more successfully."Dr. Spengler is the director of the archaeobotanical laboratories at the Max Planck Institute for the Science of Human History in Jena, Germany. "It is important look at the domestication of plants from an evolutionary ecology perspective and seek to find parallels between the evolution of plants in the wild and during early cultivation," says Spengler. "By modeling domestication as an equivalent process to evolution in the wild and setting aside the idea of conscious human innovation, we can more effectively study the questions of why and how this process occurred."
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Agriculture & Food
| 2,020 |
February 26, 2020
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https://www.sciencedaily.com/releases/2020/02/200226131331.htm
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Biodiversity increases the efficiency of energy use in grasslands
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For the first time, they did not just investigate one feeding type such as herbivores but the integrated feeding relationships across an entire ecosystem. Previous research examining the effects of biodiversity on the functioning of ecosystems focused mainly on single feeding levels (trophic levels) or simplified food chains.
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"We have analyzed an entire feeding network -- in other words, multitrophic interactions -- above- and belowground. This is indispensable for understanding the effects resulting from global species extinction," explained Dr. Sebastian T. Meyer, a researcher at the Chair for Terrestrial Ecology at the Technical University of Munich (TUM) and lead author of the study.An aboveground food chain could extend from grasses to grasshoppers and on to spiders, for example. The research group examined how much energy flows into the system, how much remains in the system -- so how much biomass is present in the system -- and eventually, how much energy is leaving the system. The main insight: The entire ecosystem's efficiency rises across all feeding levels when plant diversity increases."Seeing positive effects on one level does not imply that there cannot be simultaneous positive effects on other feeding levels," said Dr. Meyer. When a grasshopper feeds on grasses until it is saturated, this does not necessarily result in negative effects on the plant level -- with a high level of biodiversity, the system keeps itself in a balance.The group worked with data gathered through the Jena Experiment, a large-scale grassland biodiversity experiment that has been running since 2002. The research environment provided by the experiment is unique in the world and allow for the synthesis of large amounts of data.For each of the 80 plots of the Jena Experiment, the researchers assembled trophic network models of the grassland ecosystem. These contain the standing biomass on every feeding level and the flow of energy through feeding interactions between the trophic levels. In addition to plants, the study also covers herbivores, carnivores, omnivores, soil microbes, dead organic material aboveground and in the soil and decomposers that feed on these sources of organic matter."The study shows that higher plant diversity leads to more energy stored, greater energy flow and higher energy-use efficiency in the entire trophic network, therefore across all trophic levels," explained Dr. Oksana Buzhdygan from Freie Universitaet Berlin, another lead author of the study.Ecosystems with 60 plant species contained, on average, twice the amount of standing biomass in comparison to plant monocultures, which means that the total amount of resources used and recovered by plant and animal community rose with an increase in plant diversity."An enhanced ecosystem functionality on all levels can contribute to an increased insurance effect of biodiversity on ecosystem functions when environmental fluctuations occur; it also enhances the system's robustness in case of perturbations," Prof. Jana Petermann from the University of Salzburg concluded. She is the senior author of the study.This research paper highlights the importance of biodiversity for functions in and services provided by ecosystems. For instance, agricultural land use that aims at yielding a wide range of goods and services should maintain high plant diversity, for example by planting mixed crops, in order to avoid losing ecosystem resources.
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Agriculture & Food
| 2,020 |
February 25, 2020
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https://www.sciencedaily.com/releases/2020/02/200225154344.htm
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Small farmers sink or swim in globalization's tsunami
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Whether small-time farmers across the world get swept away by globalization or ride a wave of new opportunities depends largely on how much control they can get, according to a new study that takes a new, big-picture look.
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From soybean farmers in China to those who grow vanilla in Madagascar, trendy açaí in the Amazon or rubber in Myanmar, their place in new, fast-paced markets that can be both regional and global isn't fully understood until examined in context with its partners and competitors near and far. Scientists at Michigan State University (MSU) and across the world take a new look in "Understanding How Smallholders Integrated into Pericoupled and Telecoupled Systems" in this week's journal The takeaway: It's agency -- the ability these farmers have to seize some control to better their position in a global market."Given that smallholder farmers everywhere are critical to several of the United Nations Sustainable Development Goals, such as ending poverty and hunger, we need to fully understand how being swept into global markets affect them, and that means not just looking at their bottom line, but how they interact across the entire market process," said Jianguo "Jack" Liu, MSU Rachel Carson Chair in Sustainability. "We found success applying the integrated framework of telecoupling -- which allows us to look at both human and natural systems across distances -- to reveal some surprising truths."The group looked at 12 cases of smallholder farmers. Some, like farmers in Kenya, were struggling to grow more corn amidst water shortages. Others, like soybean farmers in China, found themselves at the mercy of enormous markets dominated by Brazil and the United States. Vanilla growers in Madagascar are pummeled by volatile prices while açaí berry growers in the Brazilian Amazon Delta found opportunity in the big cities to sell their newly popular crop.In each case, these smallholder farmers have traditionally been considered passive to external pressures -- swept along the fierce tide of globalization. But as Yue Dou, a former CSIS research associate now at the Institute for Environmental Studies in Amsterdam, notes following that flow paints a more nuanced picture."Globalization is not the only way that integrates smallholder to the world," Dou said. "Smallholders also send or receive flows other than agricultural goods, such as labor migration, water discharge, and technology exchange. Some of these various connections are with faraway markets, while some of them are with their neighboring villages and towns. And they co-exist. The telecoupling framework allows us to investigate the various ways smallholders connect with the world, shedding light on the agency of decision makers and potential paths to improve the environment and economics within the system."The paper examined how some açaí growers rode the new popularity of their crops to new lives by taking second homes in nearby cities which had better job and education opportunities. The Kenyan farmers found benefits in new partnerships with the Chinese, who shared new mulching systems that helped them save precious water and increase corn yields.Others struggle to grasp control. China's soybean farmers in the northern Heilongjiang Province have little ability to control global soybean prices and are forced to make decisions about what they plant on the basis of these forces, decisions that have environmental consequences as they are forced to plant crops requiring more fertilizer."From this study that synthesizes 12 cases, the authors found that if the main linkages smallholders have is with their neighbors and not the distant world, they may have more choices of livelihoods and better overall outcomes in the economy, social well-being, and the environment," Dou said. "When smallholders are connected to faraway systems, the key is to empower them to higher agency and more livelihood opportunities. Sometimes this can be improved by creating additional connections to neighbor systems."
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Agriculture & Food
| 2,020 |
February 25, 2020
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https://www.sciencedaily.com/releases/2020/02/200225113630.htm
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Genetic resistance to lethal virus found in key farmed fish species
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Resistance to a deadly disease that is affecting the second most farmed fish in the world has been found to be mainly due to differences in genes between families of the same fish.
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The breakthrough could help protect stocks of Tilapia fish, which is an important food source in Africa, Asia and South America and worth nearly $10 billion to the global economy.Since its detection in 2014, Tilapia Lake Virus (TiLV) has ravaged Tilapia populations in 16 countries across three continents.Clinical signs of the virus observed in tilapia include behavioral changes, discoloration, skin hemorrhages, loss of scales, eyeball protrusion and abdominal swelling. There are currently no treatments or vaccines for TiLV.Experts believe that selective breeding of fish with the resistance genes may be one way of limiting the damage of this disease, with up to 90 per cent of fish dying once infected.Researchers from University of Edinburgh's Roslin Institute and WorldFish analysed the genes of 1,821 Genetically Improved Farmed Tilapia (GIFT), which were tagged and placed in a pond that had an outbreak of TiLV.The fish used in this experiment were members of 124 families, and the team discovered that there was a large variation in family survival. Some family groups had no deaths, whereas others found to have a 100 per cent death rate.The team then used statistical models to show that resistance to the virus was very heritable, and this means that selective breeding to produce more resistant tilapia strains is likely to be effective.The variation in TiLV resistance were found to be independent of genetic variation in growth, meaning that any future breeding programmes for GIFT that produce fish resistant to TiLV will not adversely affect the growth of the fish, and will benefit farmers' yields.The GIFT strain was been selectively bred to be fast growing and adaptable to a wide range of environments. The strain is produced in at least 14 countries, helping to reduce poverty and hunger.Tilapia is an affordable food source for many people, particularly in developing countries. It is the fourth most consumed fish in the United States.Fast growing and a healthy source of protein, nutrients and essential fatty acids, Tilapia is easily grown on small or large fish farms.Professor Ross Houston, lead author and Personal Chair of Aquaculture Genetics at the Roslin Institute, said: "Tilapia Lake Virus poses a real problem to fish famers worldwide, impacting on the livelihoods and food security of millions of people. This research is the result of a long term collaboration between Roslin and WorldFish, and is the first step to breeding tilapia strains with improved resistance to the virus."This research project was funded with UK aid from the UK government and was undertaken in the framework of the CGIAR Research Program on Fish Agri-Food Systems. The research findings have been published in the journal Michael Phillips, Director of CGIAR Research Program on Fish Agri-Food Systems Aquaculture and Fisheries Sciences, WorldFish, said: "This is a truly exciting finding at the frontier of fish genetics. WorldFish will build on this research, with our partners in the research, donor and investment community, to accelerate the further development of resilient TiLV resistant tilapia strains and their wide accessibility to small scale fish farmers."
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Agriculture & Food
| 2,020 |
February 24, 2020
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https://www.sciencedaily.com/releases/2020/02/200224130931.htm
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Boost soybean yields by adapting photosynthesis to fleeting shadows, according to model
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Komorebi is a Japanese word that describes how light filters through leaves -- creating shifting, dappled "sunflecks" that illustrate plants' ever-changing light environment. Crops harness light energy to fix carbon dioxide into food via photosynthesis. In a special issue of
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"Soybean is the fourth most important crop in terms of overall production, but it is the top source of vegetable protein globally," said Yu Wang, a postdoctoral researcher at Illinois, who led this work for Realizing Increased Photosynthetic Efficiency (RIPE). "We found that soybean plants may lose as much as 13 percent of their productivity because they cannot adjust quickly enough to the changes in light intensity that are standard in any crop field. It may not sound like much, but in terms of the global yield -- this is massive."RIPE is an international research project that aims to improve photosynthesis to equip farmers worldwide with higher-yielding crops needed to ensure everyone has enough food to lead a healthy, productive life. RIPE is sponsored by the Bill & Melinda Gates Foundation, the U.S. Foundation for Food and Agriculture Research (FFAR), and the U.K. Government's Department for International Development (DFID).Past models have only examined hour-by-hour changes in light intensity. For this study, the team created a dynamic computational ray-tracing model that was able to predict light levels to the millimeter across every leaf for every minute of the day in a flowering soybean crop. The model also takes into account two critical factors: photoprotection and Rubisco activase.Photoprotection protects plants from sun damage. Triggered by high light levels, this process dissipates excess light energy safely as heat. But, when light levels drop, it can take minutes to hours for photoprotection to relax, or stop -- costing the plant potential yield. The team evaluated 41 varieties of soybean to find out the fastest, slowest, and average rate from induction to the relaxation of photoprotection. Less than 30 minutes is considered "short-term," and anything longer is "long-term" photoprotection.Using this new model, the team simulated a sunny and cloudy day in Champaign, Illinois. On the sunny day, long-term photoprotection was the most significant limitation of photosynthesis. On the cloudy day, photosynthesis was the most limited by short-term photoprotection and Rubisco activase, which is a helper enzyme -- triggered by light -- that turns on Rubisco to fix carbon into sugar.The RIPE project has already begun to address photoprotection limitations in soybean and other crops, including cassava, cowpea, and rice. In 2016, the team published a study in "Models like these are critical to uncovering barriers -- and solutions -- to attain this crop's full potential," said RIPE Director Stephen Long, Ikenberry Endowed University Chair Plant Biology and Crop Sciences at Illinois' Carl R. Woese Institute for Genomic Biology. "We've already begun to address these bottlenecks and seen significant gains, but this study shows us that there is still room for improvement."
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Agriculture & Food
| 2,020 |
February 24, 2020
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https://www.sciencedaily.com/releases/2020/02/200224111227.htm
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Oldest reconstructed bacterial genomes link farming, herding with emergence of new disease
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The Neolithic revolution, and the corresponding transition to agricultural and pastoralist lifestyles, represents one of the greatest cultural shifts in human history, and it has long been hypothesized that this might have also provided the opportunity for the emergence of human-adapted diseases. A new study published in Nature Ecology & Evolution led by Felix M. Key, Alexander Herbig, and Johannes Krause of the Max Planck Institute for the Science of Human History studied human remains excavated across Western Eurasia and reconstructed eight ancient
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Most pathogens do not cause any lasting impact on the skeleton, which can make identifying affected archeological remains difficult for scientists. In order to identify past diseases and reconstruct their histories, researchers have turned to genetic techniques. Using a newly developed bacterial screening pipeline called HOPS, Key and colleagues were able to overcome many of the challenges of finding ancient pathogens in metagenomics data."With our newly developed methodologies we were able to screen thousands of archaeological samples for traces of The individuals whose remains were studied came from sites located from Russia to Switzerland, representing different cultural groups, from late hunter-gatherers to nomadic herders to early farmers. "This broad spectrum in time, geography and culture allowed us, for the first time, to apply molecular genetics to link the evolution of a pathogen to the development of a new human lifestyle," explained Herbig.With the introduction of domesticated animals, increased contact with both human and animal excrement, and a dramatic change in mobility, it has long been hypothesized that "Neolithization" -- the transition to a sedentary, agricultural lifestyle -- enabled more constant and recurrent exposure to pathogens and thus the emergence of new diseases. However, prior to the current study, there was no direct molecular evidence."Ancient metagenomics provides an unprecedented window into the past of human diseases," says lead author Felix M. Key, formerly of the Max Planck Institute for the Science of Human History and now at the Massachusetts Institute of Technology. "We now have molecular data to understand the emergence and spread of pathogens thousands of years ago, and it is exciting how we can utilize high-throughput technology to address long standing questions about microbial evolution."The researchers were able to determine that all six "The fascinating possibilities of ancient DNA allow us to examine infectious microbes in the past, which sometimes puts the spotlight on diseases that today most people don't consider to be a major health concern," says Johannes Krause, director at the Max Planck Institute for the Science of Human History.The current study allows the scientists to gain a perspective on the changes in the disease over time and in different human cultural contexts. "We're beginning to understand the genetics of host adaptation in The scientists hope that the current study will illuminate the possibilities of these methods and that future research will further examine the ways that human cultural evolution has impacted and driven the evolution of human-adapted diseases.
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Agriculture & Food
| 2,020 |
February 24, 2020
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https://www.sciencedaily.com/releases/2020/02/200224100552.htm
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New strategy to protect wine grapes from smoke-taint
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It's a problem plaguing grape-growers worldwide -- in an ever-changing climate, how can they protect their crops from the undesirable effects of wildfire smoke exposure.
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A recent study by a team of UBC Okanagan researchers has led to the development of a preventative strategy for protecting grapes from volatile phenols -- flavoured compounds present in smoke that may be absorbed into ripening grapes and subsequently impact wine flavour."It's definitely one of, if not the biggest concern wine-making communities are facing today," says Wesley Zandberg, assistant professor in chemistry at UBC Okanagan and study author."When you look at the catastrophic wildfire seasons California and the Okanagan Valley have experienced in recent years, and the season Australia is experiencing now, I don't think a solution can come quickly enough," he says. "Winemakers are under a lot of pressure to find a way to protect their crops."Zandberg and his team tested multiple substances and found that applying an agricultural spray composed of phospholipids -- typically used to prevent cracking in cherries -- to wine grapes one week before exposing them to simulated forest fire smoke significantly reduced the levels of volatile phenols measured in smoke-exposed grapes at commercial maturity."The results are encouraging," says Zandberg. "This strategy has shown potential in its ability to protect crops."According to Zandberg, when wine grapes absorb compounds from smoke, the grapes react by coating the compounds in sugar using their enzymes. This sugar coating masks the smoky odour and taste of volatile phenols until it's released again by yeast during the fermentation process."Many grape-growers don't have the means to pay to test their crops, so since smoke-taint can't be reliably detected until grapes are fermented, producers have to wait weeks to know whether their plants are suitable or not," explains Zandberg. "Meanwhile, costs and risks mount as their crops sit on the vine."Zandberg adds that smoke-tainted crops can have a more devastating effect for some wine producers than others."A lot of wineries in the Okanagan Valley only use local grapes, so they don't have the option of purchasing grapes from Washington or Oregon, as they wouldn't be considered local," explains Zandberg. "When your whole business model is fermenting what you produce, you're in big trouble if your grapes are tainted."For Zandberg, it's the people and their livelihoods that keep him determined to find a solution."In 2003, the wildfires in Australia cost their wine industry $300 million dollars in lost revenue, and I imagine they'll experience a similar loss this year, if not more," he says."Our team has developed a strategy that's proven to be successful, but there's still a long way to go," admits Zandberg. "Now, we need to work on replicating and refining these results to alleviate crop losses experienced globally by the wine industry."The study was published recently in the
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Agriculture & Food
| 2,020 |
February 21, 2020
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https://www.sciencedaily.com/releases/2020/02/200221160739.htm
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Genetics of how corn can adapt faster to new climates
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Maize is a staple food all over the world. In the United States, where it's better known as corn, nearly 90 million acres were planted in 2018, earning $47.2 billion in crop cash receipts.
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But, under the effects of climate change, this signature crop may not fare so well. As the world tries to feed a population skyrocketing to nine billion by 2050, that has major implications. So, what can we do about it? The answer might be exotic.A multi-institutional team led by University of Delaware plant geneticist Randy Wisser decoded the genetic map for how maize from tropical environments can be adapted to the temperate U.S. summer growing season. Wisser sees these exotic varieties, which are rarely used in breeding, as key to creating next-era varieties of corn.The research team included scientists from UD, North Carolina State University, University of Wisconsin, University of Missouri, Iowa State University, Texas A&M University and the U.S. Department of Agriculture-Agricultural Research Service. The resulting study, highlighted by the editorial board of "If we can expand the genetic base by using exotic varieties, perhaps we can counter stresses such as emerging diseases and drought associated with growing corn in a changing climate," said Wisser, associate professor in UD's Department of Plant and Soil Sciences. "That is critical to ensuring ample production for the billions of people who depend on it for food and other products."Modern maize strains were created from only a small fraction of the global maize population. This limited infusion of diversity raises concerns about the vulnerability of American corn in a shifting climate. The U.S. Department of Agriculture (USDA) seed bank includes tens of thousands of varieties, but many are just not being used."We know that the tropical maize varieties represent our greatest reservoir of genetic diversity," said study co-author Jim Holland, a plant geneticist with the USDA Agricultural Research Service at North Carolina State. "This study improved our understanding of those genetics, so we can use this information to guide future breeding efforts to safeguard the corn crop."Certain exotic strains of maize better handle drought or waterlogging or low-nitrogen soil, for example. But because these strains have evolved outside the U.S., they are not immediately suited to states like Delaware. So, exotics first need to be pre-adapted.In prior work, Wisser and his colleagues showed how 10 years of repeated genetic selection was required to adapt a tropical strain of maize to the temperate U.S. Co-author Arnel Hallauer spent a decade adapting the population through selective breeding, so it could flourish in an environment like Delaware."What's so cool now is that we could go back to the original generations from Dr. Hallauer and grow them side by side in the same field," Wisser said of the first-of-its-kind experimental design. "This allows us to rule out the influence of the environment on each trait, directly exposing the genetic component of evolution. This has opened a 'back to the future' channel where we can redesign our approach to developing modern varieties."While extremely impressive, a decade to adapt exotic maize to new environments is a lot of time when the climate change clock is ticking."Unfortunately, this process takes 10 years, which is not counting ongoing evaluations and integrating the exotic variations into more commonly used types of maize," Wisser said. "With the climate threats we face, that's a long time. So, gaining insights into this evolutionary process will help us devise ways to shorten the time span."Wisser isn't wasting any time as he explores ways to bolster corn's ability to survive and thrive. He and Holland are working on a new project to cut that time span in half.In cutting-edge research funded by the U.S. Department of Agriculture's National Institute of Food and Agriculture, the team is analyzing how corn genomes behave in a target environment as they aim to formulate a predictive model for fitness."What we're doing is sequencing the genomes and measuring traits like flowering time or disease for individuals in one generation. From this, we can generate a lookup table that allows us to foresee which individuals in the next generation have the best traits based on their genetic profiles alone," Wisser said. "And our lookup table can be tailored to predict how the individuals will behave in a particular environment or location like Delaware."That means plant breeders could grow a second generation of corn anywhere outside of Delaware, but still predict which individuals would be the most fit for Delaware's environment."For instance, even if the plants are grown at a location where a disease is not present, our prediction model can still select the resistant plants and cross them to enrich the genes that underlie resistance," Wisser said.With this approach, researchers don't have to wait out a Delaware winter, so they can continue to pre-adapt the population for at least one extra generation per year. That's how 10 years of selective breeding for pre-adaptation could become five, providing a quicker route to access exotic genes.This new effort connects to the Genomes To Fields (G2F) Initiative, developed in 2013 for understanding and capitalizing on the link between genomes and crop performance for the benefit of growers, consumers and society.If Wisser and Holland can develop a method to rapidly pre-adapt exotics, this opens a lane for G2F to test the impact of these unique genomes on crop performance."Our goal is to advance the science so breeders can draw on a wider array of the diversity that has accumulated across thousands of years of evolution," explained Wisser, who has been involved in the public-private initiative since its beginning. "In turn, they can produce improved varieties for producers and consumers facing the challenges of climate change."
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Agriculture & Food
| 2,020 |
February 20, 2020
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https://www.sciencedaily.com/releases/2020/02/200220130500.htm
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New artificial intelligence algorithm better predicts corn yield
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With some reports predicting the precision agriculture market will reach $12.9 billion by 2027, there is an increasing need to develop sophisticated data-analysis solutions that can guide management decisions in real time. A new study from an interdisciplinary research group at University of Illinois offers a promising approach to efficiently and accurately process precision ag data.
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"We're trying to change how people run agronomic research. Instead of establishing a small field plot, running statistics, and publishing the means, what we're trying to do involves the farmer far more directly. We are running experiments with farmers' machinery in their own fields. We can detect site-specific responses to different inputs. And we can see whether there's a response in different parts of the field," says Nicolas Martin, assistant professor in the Department of Crop Sciences at Illinois and co-author of the study.He adds, "We developed methodology using deep learning to generate yield predictions. It incorporates information from different topographic variables, soil electroconductivity, as well as nitrogen and seed rate treatments we applied throughout nine Midwestern corn fields."Martin and his team worked with 2017 and 2018 data from the Data Intensive Farm Management project, in which seeds and nitrogen fertilizer were applied at varying rates across 226 fields in the Midwest, Brazil, Argentina, and South Africa. On-ground measurements were paired with high-resolution satellite images from PlanetLab to predict yield.Fields were digitally broken down into 5-meter (approximately 16-foot) squares. Data on soil, elevation, nitrogen application rate, and seed rate were fed into the computer for each square, with the goal of learning how the factors interact to predict yield in that square.The researchers approached their analysis with a type of machine learning or artificial intelligence known as a convolutional neural network (CNN). Some types of machine learning start with patterns and ask the computer to fit new bits of data into those existing patterns. Convolutional neural networks are blind to existing patterns. Instead, they take bits of data and learn the patterns that organize them, similar to the way humans organize new information through neural networks in the brain. The CNN process, which predicted yield with high accuracy, was also compared to other machine learning algorithms and traditional statistical techniques."We don't really know what is causing differences in yield responses to inputs across a field. Sometimes people have an idea that a certain spot should respond really strongly to nitrogen and it doesn't, or vice versa. The CNN can pick up on hidden patterns that may be causing a response," Martin says. "And when we compared several methods, we found out that the CNN was working very well to explain yield variation."Using artificial intelligence to untangle data from precision agriculture is still relatively new, but Martin says his experiment merely grazes the tip of the iceberg in terms of CNN's potential applications. "Eventually, we could use it to come up with optimum recommendations for a given combination of inputs and site constraints."
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Agriculture & Food
| 2,020 |
February 19, 2020
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https://www.sciencedaily.com/releases/2020/02/200219124229.htm
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Dog domestication during ice age
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Analysis of Paleolithic-era teeth from a 28,500-year-old fossil site in the Czech Republic provides supporting evidence for two groups of canids -- one dog-like and the other wolf-like -- with differing diets, which is consistent with the early domestication of dogs.
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The study, published in the The researchers performed dental microwear texture analysis on a sample of fossils from the Předmostí site, which contains both wolf-like and dog-like canids. Canids are simply mammals of the dog family. The researchers identified distinctive microwear patterns for each canid morphotype. Compared to the wolf-like canids, the teeth of the early dog canids -- called "protodogs" by the researchers -- had larger wear scars, indicating a diet that included hard, brittle foods. The teeth of the wolf-like canids had smaller scars, suggesting they consumed more flesh, likely from mammoth, as shown by previous research.This greater durophagy -- animal eating behavior suggesting the consumption of hard objects -- among the dog-like canids means they likely consumed bones and other less desirable food scraps within human settlement areas, Ungar said. It provides supporting evidence that there were two types of canids at the site, each with a distinct diet, which is consistent with other evidence of early-stage domestication."Our primary goal was to test whether these two morphotypes expressed notable differences in behavior, based on wear patterns," said Ungar. "Dental microwear is a behavioral signal that can appear generations before morphological changes are established in a population, and it shows great promise in using the archaeological record to distinguish protodogs from wolves."Dog domestication is the earliest example of animal husbandry and the only type of domestication that occurred well before the earliest definitive evidence of agriculture. However, there is robust scientific debate about the timing and circumstances of the initial domestication of dogs, with estimates varying between 15,000 and 40,000 years ago, well into the Ice Age, when people had a hunter-gatherer way of life. There is also debate about why wolves were first domesticated to become dogs. From an anthropological perspective, the timing of the domestication process is important for understanding early cognition, behavior and the ecology of early Homo sapiens.
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Agriculture & Food
| 2,020 |
February 19, 2020
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https://www.sciencedaily.com/releases/2020/02/200219124007.htm
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Veggie-loving fish could be the new white meat
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A secret to survival amid rising global temperatures could be dwelling in the tidepools of the U.S. West Coast. Findings by University of California, Irvine biologists studying the genome of an unusual fish residing in those waters offer new possibilities for humans to obtain dietary protein as climate change imperils traditional sources. Their paper appears in
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The fish, Cebidichthys violaceus, is colloquially known as the monkeyface prickleback. With an acidic stomach and small and large intestines, it has a digestive system similar to that of humans. The monkeyface prickleback is among just five percent of the 30-thousand fish species that are vegetarian, nourishing themselves only with the specialized algae in the tidepools where they live.This characteristic captured the attention of Donovan German, associate professor of ecology & evolutionary biology, researcher Joseph Heras and colleagues. They wanted to figure out how the monkeyface prickleback survives on a food source containing a low level of lipids, which are essential for all living beings. By sequencing and assembling a high-quality genome for the fish, the team discovered the secret."We found that the monkeyface prickleback's digestive system is excellent at breaking down starch, which we anticipated," said German. "But we also learned it has adapted to be very efficient at breaking down lipids, even though lipids comprise just five percent of the algae's composition. It is a compelling example of what we call 'digestive specialization' in the genome."With climate change making the raising of livestock less sustainable, the discovery holds promise for developing new sources of protein for human consumption. In particular, it could be important for aquaculture, which is a possible alternative but is contending with the issue of what to feed the fish being raised."Using plant-based food ingredients reduces pollution and costs less," said Heras, the paper's first author. "However, most aquaculture fish are carnivores and can't handle plant lipids. Sequencing this genome has provided us a better understanding of what types of genes are necessary for breaking down plant material. If we scan additional fish genomes, we may find omnivorous fish with the right genes that could provide new candidates for sustainable aquaculture."The monkeyface prickleback grows to as much as three feet long and six pounds in weight. It can live on land for up to 37 straight hours, thanks to the ability to breathe above water as well as under. In the past decade, it has become a culinary delicacy, appearing on plates in a number of high-end restaurants. Its flavor belies its imposing appearance."The taste is actually delicate and mild," said German.
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Agriculture & Food
| 2,020 |
February 19, 2020
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https://www.sciencedaily.com/releases/2020/02/200219113749.htm
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Weed-derived compounds in Serbian groundwater could contribute to endemic kidney disease
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People living in Balkan farming villages along the Danube River have long suffered from a unique type of kidney disease known as Balkan endemic nephropathy. Recently, scientists linked the disorder to compounds from a local weed that could be taken up into food crops from the soil. Now, researchers reporting in ACS' journal
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Aristolochic acids (AAs) were recognized as potent kidney toxins after people taking herbal medicines containing the compounds developed kidney disease. A weed that is widespread in the Balkan regions, To measure AAs in water, the researchers used a positively charged silica-based sorbent to collect AAs, which are negatively charged, from water samples. They released the AAs from the sorbent and then converted the substances to aristolactams for detection by mass spectrometry. The team applied this new method to the analysis of 123 water samples collected from wells in rural Serbia. They found that the groundwater was extensively contaminated with one form of AA at nanogram/liter levels. These results suggest that drinking, cooking and irrigating with the contaminated water is a highly important, but previously unrecognized, source of AA exposure. Weed control of The authors acknowledge funding from the TUYF Charitable Trust and the University Grants Committee of Hong Kong.
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Agriculture & Food
| 2,020 |
February 18, 2020
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https://www.sciencedaily.com/releases/2020/02/200218073457.htm
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Amazon forest disturbance is changing how plants are dispersed
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The study looked at areas in the Brazilian Amazon with varying levels of disturbance from activities like logging or burning. The researchers found that not only did human disturbance reduce overall tree diversity, it increased the proportion of trees with seeds dispersed by animals as opposed to other mechanisms like wind.
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Disturbance also led to a significant shift towards small-seeded species, which are more likely to be dispersed by smaller animals like birds and bats. It is not clear if these trees can support larger fruit-eating animals that specialise in large-seeded plants and are important for their seed dispersal.The researchers observed similar effects in secondary (re-grown) forests recovering from clear felling. Older secondary forest had functionally similar plants to the most heavily disturbed primary forest.Dr Joseph Hawes, lead author of the study said: "Previous studies in disturbed tropical forests have often found plant communities are more likely to rely on seeds dispersed by wind and other abiotic mechanisms, rather than fruit-eating animals. In contrast, our study found that disturbance led to tree communities in which a greater proportion of species and individuals rely on animal dispersal."There are likely multiple reasons for this shift. Forest fires and selective logging disproportionately affect certain tree species, which can influence dispersal patterns. Hunting can also reduce seed dispersal by large birds and mammals, leaving smaller animals to disperse smaller seeds.On the implications of a shift towards smaller-seeded tree species, Dr Hawes added: "Smaller-seeded tree species are becoming more prevalent in forests heavily disturbed by human activity. As larger-seeded tree species are also often those with higher wood densities, these changes in forest composition could have longer-term implications for both the carbon storage and drought sensitivity of tropical forests."Professor Jos Barlow, co-author said: "This highlights the especially important role played by large-bodied fruit eating animals in the Amazon and helps to underline the need to avoid the loss of these animals and to help encourage their recovery in human-modified forests."Dr Ima Vieira, co-author said: "Most forest restoration focusses on the vegetation, but we also need to consider fauna in restoration projects because of their important mutualistic interactions with plants. Our study provides further evidence that fauna are key to restoring biodiversity-rich ecosystems in the Amazon."Dr Joice Ferreira, co-author said: "Avoiding forest loss and degradation should be a priority in public policies as the disruption of plant-animal interactions can lead to catastrophic cascading effects. In Brazil, ambitious restoration goals have been proposed (12 million hectares up to 2030). Disregarding the role of biotic interactions could undermine the success of such efforts."Tropical forests are fundamentally important for global biodiversity, climate regulation and human livelihoods, but they're increasingly threatened by human impacts. 80% of tropical forest landscapes currently exist in a modified state, either as degraded primary forest or recovering secondary forest."Pressure from agricultural expansion, including cattle ranching and mechanised farming e.g. soya, is high in the eastern Amazon but this pressure is not uniform, and some areas are more affected than others. This is also the case for pressures such as from silviculture plantations, selective logging and fire." said Dr Hawes.The functional traits of species are important components of an ecosystem and can support key ecological processes even when species richness is reduced. Compared to other plant traits like leaf area and wood density, reproductive traits are relatively understudied despite their importance to mutualistic relationships and role in recruiting new trees.In this study the researchers surveyed 230 forest plots across two regions in the Eastern Brazilian Amazon. The plots covered a gradient of disturbance in forests from undisturbed primary forest, to forest that that had been logged, burned, or logged-and-burned. In total the researchers recorded 26,533 live tree stems from 846 tree species.Using herbariums and research literature, the researchers compiled information on fruit and seed traits like size, type, shape and dispersal method for each species.The study focussed on changes in plant communities, rather than changes in animal communities in human disturbed forests. The researchers warn that isolating these disturbance-specific relationships will likely be difficult due to the multiple drivers of change in human-modified landscapes.Outside of seed dispersal method, the researchers did not consider other factors that may influence successful plant recruitment. This was limited by a shortage of information on what constitutes effective seed dispersal by different animal species.Dr Hawes said: "One of the next steps in understanding the long-term ecological impacts of human disturbances in tropical forests is to build a comprehensive database for plant traits, including measurements such as seed size that were included in our study. We have contributed our data to the TRY Plant Trait Database, a global research effort to compile and provide free and open access to plant trait data."Professor Jos Barlow said: "Much of the work was funded by a Brazilian research council grant for visiting professors, and it highlights the importance of long-term scientific collaboration for guiding forest management in the Amazon."
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Agriculture & Food
| 2,020 |
February 18, 2020
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https://www.sciencedaily.com/releases/2020/02/200218104745.htm
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Crops provide chimpanzees with more energy than wild foods
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A University of Kent study has found that cultivated foods offer chimpanzees in West Africa more energetic benefits than wild foods available in the region.
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The findings have made a significant development for our further understanding into human-primate coexistence and can help to inform conservation efforts for future improvement, particularly in locations where agricultural expansion is encroaching on tropical forests.Dr Nicola Bryson-Morrison and Dr Tatyana Humle of Kent's Durrell Institute of Conservation and Ecology, examined the macronutrient content of 24 wild and 11 crop foods consumed by chimpanzees in Bossou, Guinea, West Africa.It was found that cultivated fruits were higher in easily digestible carbohydrates and lower in insoluble fibre than wild fruits, while wild fruits were higher in protein. Higher easily digestible carbohydrates provide more energy.Oil palm food parts were relatively rich in carbohydrates, protein, lipids, and fermentable fibre, adding nutritional support for the importance of the oil palm for West African chimpanzees inhabiting human-dominated environments.When compared with published macronutrient measures of crops from Bulindi, Uganda, East Africa, the composition of wild fruits, leaves, and pith were consistent with previous reports for primate diets. Furthermore, no differences were found in the composition of cultivated fruits, suggesting macronutrient content alone does not explain differences in primates' crop selection. This confirms the idea that food-crop selection in chimpanzees is partly cultural.Dr Bryson-Morrison said: 'Our research has built on the current understanding of chimpanzee feeding ecology within forest?agricultural mosaics. By providing further validation that nutritionally dense crops offer primates energetic benefits over wild foods, this study has widened scope for more research into human-primate interactions in relation to shared resources and species-specific dietary needs.'
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Agriculture & Food
| 2,020 |
February 14, 2020
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https://www.sciencedaily.com/releases/2020/02/200214161328.htm
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Major study shows climate change can cause abrupt impacts on dryland ecosystems
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A Swansea University academic has contributed to a major study published in the journal
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Dr Rocio Hernandez-Clemente, a senior lecturer from the University's Department of Geography, joined an international team of researchers from the Dryland Ecology and Global Change Lab at the University of Alicante to examine the Earth's dryland ecosystem, which covers 41% of the world's surface and is home to around a third of its population.The study found for the first time that as aridity increases, dryland ecosystems undergo a series of abrupt changes. This results first in drastic reductions in the capacity of plants to fix carbon from the atmosphere, followed by substantial declines of soil fertility and ending with the disappearance of vegetation under the most arid and extreme conditions.The team found that increases in aridity in line with current climate change forecast, led to abrupt shifts in dryland ecosystems worldwide which limit their capacity to sustain life. This is because climate largely determines the amount and types of plants that can be found in a given place, how fertile the soil is, and how the landscapes look like. Understanding how changes in climatic conditions affect organisms and the ecosystem processes and services that depend on them, such as food and biomass production, is key to understanding, forecasting and mitigating climate change impacts on both ecosystems and societies.The team led by Dr. Miguel Berdugo, at the University of Alicante, pulled together the largest compilation of empirical data to date to evaluate how key ecosystems change along the wide aridity gradients that can be found in drylands worldwide. Dr Hernandez-Clemente performed the data extraction, processing and Normalized Difference Vegetation Index data analysis of 60000 points distributed worldwide and used as an indicator of plant productivity in drylands. She also contributed to the quality assessment analysis and validation of the data and derived trends to detect abrupt shifts through remote sensing data.Dr. Berdugo said: "The purpose of our work was to look at how these ecosystem change as we move towards more arid zones in order to better understand what we may expect in the future as the climate becomes drier, and more arid, in drylands worldwide."The study identified three phases of accelerated ecosystem change in response to increases in aridity, measured as the inverse ratio between rainfall and the rate by which water evaporates from the land to the atmosphere.The key findings of the study were:According to climatic forecasts, more than 20% of land may cross one or several of the thresholds identified in this study by 2100 due to climate change.Dr Berdugo said: "Life will not disappear from drylands with forecasted aridity increases, but our findings suggest that their ecosystems may experience abrupt changes that will reduce their capacity to provide ecosystem services more than 2 billion people, such as soil fertility and biomass production."Dr Rocio Hernandez-Clemente said: "The reduced global ability of the land to sustain life is predicted to become an increasing problem with climate change. This study demonstrates the possibility of detecting abrupt changes and monitoring how land turns into desertification processes with remote sensing data."The use of satellite image data helps scientists to monitor, predict and quantify the consequences of the increasing aridity in drylands ecosystems worldwide. International cooperation is essential for assessing land degradation and abrupt shifts. The next steps of our research will be focused in the use of earth observation data for look for changes of desertification processes."
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Agriculture & Food
| 2,020 |
February 14, 2020
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https://www.sciencedaily.com/releases/2020/02/200214134705.htm
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5200-year-old grains in the eastern Altai Mountains redate trans-Eurasian crop exchange
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Most people are familiar with the historical Silk Road, but fewer people realize that the exchange of items, ideas, technology, and human genes through the mountain valleys of Central Asia started almost three millennia before organized trade networks formed. These pre-Silk Road exchange routes played an important role in shaping human cultural developments across Europe and Asia, and facilitated the dispersal of technologies such as horse breeding and metal smelting into East Asia. One of the most impactful effects of this process of ancient cultural dispersal was the westward spread of northeast Asian crops and the eastward spread of southwest Asian crops. However, until the past few years, a lack of archaeobotanical studies in Central Asia left a dearth of data relating to when and how this process occurred.
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This new study, led by scientists from the Chinese Academy of Sciences and the Max Planck Institute for the Science of Human History, provides details of recently recovered ancient grains from the far northern regions of Inner Asia. Radiocarbon dating shows that the grains include the oldest examples of wheat and barley ever recovered this far north in Asia, pushing back the dates for early farming in the region by at least a millenium. These are also the earliest domesticated plants reported from the northern half of Central Asia, the core of the ancient exchange corridor. This study pulls together sedimentary pollen and ancient wood charcoal data with archaeobotanical remains from the Tiangtian archaeological site in the Chinese Altai Mountains to reveal how humans cultivated crops at such northern latitudes. This study illustrates how adaptable ancient crop plants were to new ecological constraints and how human cultural practices allowed people to survive in unpredictable environments.The ancient relatives of wheat and barley plants evolved to grow in the warm and dry climate of the eastern Mediterranean and southwest Asia. However, this study illustrates that ancient peoples were cultivating these grasses over five and a half thousand kilometers to the northeast of where they originally evolved to grow. In this study, Dr. Xinying Zhou and his colleagues integrate paleoenvironmental proxies to determine how extreme the ecology was around the archaeological cave site of Tangtian more than five millennia ago, at the time of its occupation. The site is located high in the Altai Mountains on a cold,dry landscape today; however, the study shows that the ecological setting around the site was slightly warmer and more humid at the time when people lived in and around this cave.The slightly warmer regional conditions were likely the result of shifting air masses bringing warmer, wetter air from the south. In addition to early farmers using a specific regional climate pocket to grow crops in North Asia, analysis showed that the crops they grew evolved to survive in such northern regions. The results of this study provide scholars with evidence for when certain evolutionary changes in these grasses occurred, including changes in the programed reliance of day length, which signals to the plant when to flower, and a greater resistance to cold climates.The ancient dispersal of crops across Inner Asia has received a lot of attention from biologists and archaeologists in recent years; as Dr. Spengler, one of the study's lead authors, discusses in his recent book Fruit from the Sands, these ancient exchange routes shaped the course of human history. The mingling of crops originating from opposite ends of Asia resulted in the crop-rotation cycles that fueled demographic growth and led to imperial formation. East Asian millets would become one of the most important crops in ancient Europe and wheat would become one of the most important crops in East Asia by the Han Dynasty. While the long tradition of rice cultivation in East Asia made rice a staple of the Asian kitchen, Chinese cuisine would be unrecognizable without wheat-based food items like steamed buns, dumplings, and noodles. The discovery that these plants dispersed across Eurasia earlier than previously understood will have lasting impacts on the study of cultivation and labor practices in ancient Eurasia, as well as the history cultural contact and shifts in culinary systems throughout time.These new discoveries provide reason to question these views, and seem to suggest that mixed small-scale human populations made major contributions to world history through migration and cultural and technological exchange. "This study not only presents the earliest dates for domesticated grains in far North Asia," says Professor Xiaoqiang Li, director of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, "it represents the earliest beginning of a trans-Eurasian exchange that would eventually develop into the great Silk Road."Dr. Xinying Zhou, who headed the study and directs a research team at the IVPP in Beijing, emphasizes that "this discovery is a testament to human ingenuity and the amazing coevolutionary bond between people and the plants that they maintain in their cultivated fields."
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Agriculture & Food
| 2,020 |
February 13, 2020
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https://www.sciencedaily.com/releases/2020/02/200213135758.htm
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Consumers may be wasting more than twice as much food as commonly believed
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Consumers are likely wasting much more food than commonly believed, according to a study published February 12, 2020 in the open-access journal
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The Food and Agriculture Organization of the United Nations (FAO) estimated that in 2005, one third of all food available for human consumption was wasted (in this context, "waste" refers to food fit for human consumption which went uneaten). This figure has continued to serve as reference for the extent of global food waste. However, the FAO methodology does not factor in consumer behavior regarding food waste and considers food supply alone in determining the extent of food waste. This study is the first to investigate if and how consumer affluence may affect food waste.Using a human metabolism model and data from FAO, the World Bank, and the World Health Organization, van den Bos Verma and colleagues quantified the relationship between food waste and consumer affluence. Using this model, they created an international dataset providing estimates of global as well as country specific food waste.The authors found that once consumer affluence reaches a spending threshold of approximately $6.70/day per capita per day, consumer food waste starts to rise- increasing rapidly with rising affluence at first, and then at much slower rates at higher levels of affluence.Their data also showed that FAO's estimates of consumer food waste may be too low. While FAO estimated food waste to be 214 Kcal/day per capita in 2015, this model estimated food waste as 527 Kcal/day per capita for the same year.This work relies on the accuracy of FAO's data, which may not always be complete (for instance, low-income country surveys don't always include food from subsistence farming). The authors also note there are many consumer attributes that may affect food wastage beyond affluence.However, this work suggests that to achieve low global food waste, a joint focus on 1) reducing high food waste levels in high income countries, and 2) preventing waste levels from rising rapidly in lower-middle income countries where affluence is increasing may be needed. The authors believe that the method behind this study can be used as a basis to introduce the affluence elasticity of waste as a new concept in future models, better understand and assess current food waste magnitudes, and help measure global progress in reducing food waste.The authors add: "Novel research using energy requirement and consumer affluence data shows that consumers waste more than twice as much food as is commonly believed. It provides a new globally comparable base against which one can measure progress on the international food waste target (SDG12), and suggests a threshold level of consumer affluence around which to launch intervention policies to prevent food waste from becoming a big problem."
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Agriculture & Food
| 2,020 |
February 13, 2020
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https://www.sciencedaily.com/releases/2020/02/200213091212.htm
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Herd immunity: Disease transmission from wildlife to livestock
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Transmission of diseases from wildlife to livestock is a common threat in Alberta, according to new research by University of Alberta biologists. Foothills in the southwestern part of the province are home to wild elk as well as cattle on ranchlands -- and when the species intermingle, the potential for disease to spread grows.
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"One of the biggest risks to the livestock industry is the transmission of disease from wildlife to livestock," said Mark Boyce, professor in the Department of Biological Sciences. "There is a long list of diseases that occur between livestock and wildlife, including anthrax, bovine tuberculosis, brucellosis, and many species of worms. And in addition to infecting one another, many of the diseases that are shared by wildlife and livestock are zoonotic, meaning that they also can infect humans."The researchers used data gathered from combined with cattle management information from 16 cattle operations in southern Alberta to identify locations and times where the probability of disease transmission is high. For example, the highest risk occurs in winter months, when livestock and elk are in the same pastures and accessing the same resources.Based on these data, the researchers have developed guidelines to help producers minimize the risk of infection."Livestock management that minimizes the risk of contact with wildlife will reduce the risk of disease transmission," said Boyce. "This includes keeping cattle in pastures near farm buildings during winter and calving season. It is also important to keep mineral supplements and hay next to ranch buildings, again to reduce the contact between cattle and elk.
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Agriculture & Food
| 2,020 |
February 12, 2020
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https://www.sciencedaily.com/releases/2020/02/200212164643.htm
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Fossilized insect from 100 million years ago is oldest record of primitive bee with pollen
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Beetle parasites clinging to a primitive bee 100 million years ago may have caused the flight error that, while deadly for the insect, is a boon for science today.
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The female bee, which became stuck in tree resin and thus preserved in amber, has been identified by Oregon State University researcher George Poinar Jr. as a new family, genus and species.The mid-Cretaceous fossil from Myanmar provides the first record of a primitive bee with pollen and also the first record of the beetle parasites, which continue to show up on modern bees today.The findings, published in Insect pollinators aid the reproduction of flowering plants around the globe and are also ecologically critical as promoters of biodiversity. Bees are the standard bearer because they're usually present in the greatest numbers and because they're the only pollinator group that feeds exclusively on nectar and pollen throughout their life cycle.Bees evolved from apoid wasps, which are carnivores. Not much is known, however, about the changes wasps underwent as they made that dietary transition.Poinar, professor emeritus in the OSU College of Science and an international expert in using plant and animal life forms preserved in amber to learn more about the biology and ecology of the distant past, classified the new find as Discoscapa apicula, in the family Discoscapidae.The fossilized bee shares traits with modern bees -- including plumose hairs, a rounded pronotal lobe, and a pair of spurs on the hind tibia -- and also those of apoid wasps, such as very low-placed antennal sockets and certain wing-vein features."Something unique about the new family that's not found on any extant or extinct lineage of apoid wasps or bees is a bifurcated scape," Poinar said, referring to a two-segment antennae base. "The fossil record of bees is pretty vast, but most are from the last 65 million years and look a lot like modern bees. Fossils like the one in this study can tell us about the changes certain wasp lineages underwent as they became palynivores -- pollen eaters."Numerous pollen grains on Discoscapa apicula show the bee had recently been to one or more flowers."Additional evidence that the fossil bee had visited flowers are the 21 beetle triungulins -- larvae -- in the same piece of amber that were hitching a ride back to the bee's nest to dine on bee larvae and their provisions, food left by the female," Poinar said. "It is certainly possible that the large number of triungulins caused the bee to accidently fly into the resin."
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Agriculture & Food
| 2,020 |
February 12, 2020
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https://www.sciencedaily.com/releases/2020/02/200212150139.htm
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Climate-driven farming 'frontiers' pose major environmental risks
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Future farming in regions that were previously unsuitable for agriculture could significantly impact biodiversity, water resources, and greenhouse gas emissions worldwide. Lee Hannah of Conservation International's Betty and Gordon Moore Center for Science in Arlington, Virginia, and colleagues present a new analysis of these risks in the open access journal
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As Earth's climate warms, some regions at higher altitudes and latitudes may become more suitable for farming, potentially helping to feed a growing global population. However, recent research suggests these agricultural "frontiers" pose threats to wildlife, water resources, and other environmental factors. Such risks are poorly understood at the global level.To help clarify these risks, Hannah and colleagues conducted a first-of-its-kind global modeling analysis of climate change-driven shifts in crop suitability and their environmental effects. The analysis incorporated the predictions of 17 global climate models and enabled assessment of different regions' future suitability for 12 key crops, including corn, sugar, and cotton.The modeling results suggest that climate change will increase the global amount of land suitable for key crops by more than 30 percent, mostly in upper latitudes of the Northern Hemisphere and in mountains around the world. Farming these frontiers could pollute downstream water resources that serve 1.8 billion people. It could also decrease biodiversity in tropical mountains; the predicted frontiers overlap 19 global diversity hotspots, as well as critical bird habitats.In addition, farming of agricultural frontiers has the potential to release up to 177 gigatons of carbon naturally stored in frontier soils into the atmosphere. This amount is equivalent to more than 100 years' worth of present-day carbon dioxide emissions in the U.S., and its release could accelerate global warming.The new findings could help shape efforts to manage farming in agricultural frontiers, such that communities can benefit from new farmland while mitigating the environmental consequences.The authors add: "In a warming world, there will be new opportunities and challenges in the north. This work highlights how we must approach the idea of developing new farmland very cautiously and be extremely mindful of potential negative environmental impacts."
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Agriculture & Food
| 2,020 |
February 12, 2020
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https://www.sciencedaily.com/releases/2020/02/200212131516.htm
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Pollinating opossums confirm decades-long theory
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In Brazil there is a plant so strange that researchers predicted -- and 27 years later, proved -- that opossums are key to its pollination. The findings are published in the Ecological Society of America's journal
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The plant While most species in the Balanophoraceae plant family are primarily pollinated by bees and wasps, researchers at São Paulo State University in Botucatu, Brazil hypothesized something different. They thought that opossums, with their opposable thumbs, would be a key pollinator for In the early 1990s Patrícia Morellato, a professor at the university, first made the prediction. She and her colleagues studied the plant and they captured an opossum with nectar on its nose. There observations went unpublished because they did not record or obtain direct evidence of the opossums pollinating the flowers.Felipe Amorim, assistant professor at the university and lead author on this study, did not encounter the plant until 2017, but hypothesized that a non-flying mammal is needed for pollination based on the flower morphology. In April 2019 his students independently hypothesized that perhaps rodents could act as the main pollinators of this species. "At that time, neither of us knew anything about the unpublished observations made by Patrícia in the '90s,'" he explains.In May 2019 Amorim and a team of researchers went to Serra do Japi Biological Reserve, located about 50 km from the area studied by Morellato, and set up night-vision cameras to record the activity of nocturnal flower visitors. The cameras captured opossums removing bracts from the fungus-like plant and pushing their faces into the flowers to eat the nectar. It was the first direct evidence of opossums pollinating the plant.Amorim sent his colleague Morellato the footage. "When she watched the videos," he says, "she sent me a voice message as excited as we were when we first saw the opossum visiting the flowers, because it was the first time she saw something she predicted two and a half-decades ago!"The researchers had made the opossum prediction based on "pollination syndrome" -- the concept that floral attributes such as color, morphology, scent, and size reflect the adaptation of a plant species to pollination by a certain group of animals. Opossums, having "hands" with opposable thumbs, are capable of peeling back the scale-like leafs covering the flowers of "Based on the flower morphology," Amorim says, "Morellato, my students, and I could safely predict that this plant should be pollinated by non-flying mammals, but the occurrence of hummingbirds coming to the ground to visit these flowers was something completely unexpected to me." Morellato had not seen any hummingbirds visiting this species at her study site during the '90s, but researchers have more recently obtained indirect evidence that hummingbirds visit the plant in both study locations.The authors hope to continue studying the pollinators of Overall, the story is an interesting one to tell, the culmination of nearly three decades of prediction and observation based on the hard shell surrounding a bunch of tiny flowers. Amorim contemplates that "at the time that non-flying mammals were first predicted as the pollinators of this fungus-like plant, I was about 11 years old, and most of the authors of this study haven't even had born!"
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Agriculture & Food
| 2,020 |
February 11, 2020
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https://www.sciencedaily.com/releases/2020/02/200211121510.htm
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Researchers discover new arsenic compounds in rice fields
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University of Bayreuth researchers, together with scientists from Italy and China, have for the first time systematically investigated under which conditions, and to what extent, sulphur-containing arsenic compounds are formed in rice-growing soils. To date, these thioarsenates have not been taken into account in assessments of the health effects of rice consumption. In the journal
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The research team, headed by the Bayreuth environmental geochemist Prof. Dr. Britta Planer-Friedrich, has developed a measuring method by means of which thioarsenates in rice soils can be reliably detected. Up to now, the methods routinely used to monitor arsenic in rice fields have not been sufficient for this purpose. This is because they are not able to identify sulphur-containing arsenic compounds as such, or to distinguish them from oxygen-containing arsenic compounds. This shortcoming is highly problematic in terms of possible health risks. At least one organic sulphur-containing arsenic compound discovered in rice fields is already known to be carcinogenic. This makes it all the more important to specifically detect organic sulphur-containing arsenic compounds, and to examine them for their toxicity. Presumably, these compounds have been confused with non-toxic organic oxygenated arsenic compounds up to now due to inadequate measurement procedures."The uptake of the various thioarsenates in rice plants and the potential risks to human health arising from them urgently require further research. Rice is the world's most important foodstuff and secures the basis of life for more than one half of the world's population," explains Planer-Friedrich, and calls for legally defined limits to be set for all toxic arsenic compounds in future. "Analytical procedures for limit monitoring, which correctly detect all of these compounds, must become routine," says the Bayreuth scientist. At the moment, there is only a legal limit for inorganic oxygenated arsenic compounds, while organic oxygenated arsenic compounds are still categorized as non-toxic.With their new measuring method, the researchers have observed the formation of sulphur-containing arsenic compounds over long periods of time in rice fields in Italy and China. It turns out the amounts of thioarsenates occurring are linked significantly to the pH-values of the soils and other easily measurable parameters. "These findings contain valuable starting points for the development of forecasting methods. If in future we could predict, without great technical effort, on which rice fields particularly large or only small amounts of sulphur-containing arsenic compounds are to be expected, it would be an important contribution to the assessment of health risks," says the Bayreuth PhD student and first author of the study, Jiajia Wang MSc.The authors of the new study consider further research to be indispensable in order to be able to scientifically assess the health risks posed by thioarsenates. For example, the exact transport routes with which these arsenic compounds are transferred from the rice fields to the rice grains, and to what extent, must be clarified. Studies in Bayreuth laboratories have already confirmed that sulphur-containing arsenic compounds can enter the rice plant and even reach the rice grain. However, based on our current state of knowledge, it cannot be ruled out that the total arsenic contamination of rice harvests could even decrease if sulphur-containing instead of oxygen-containing arsenic compounds are formed in the soil. This would be the case if sulphur-containing arsenic compounds were largely retained in the soil, or if rice plants were less able to take up these compounds.At the University of Bayreuth, these relationships are being investigated in the research groups of Prof. Dr. Britta Planer-Friedrich and of plant physiologist Prof. Dr. Stephan Clemens. The German Research Foundation (DFG) and the Federal Ministry of Education and Research (BMBF) are supporting these interdisciplinary research projects. "Our further studies will show whether thioarsenates as a whole represent a risk or an opportunity for the production of rice containing the lowest possible amounts of arsenic, which is hazardous to health. Only then can further directives for water or soil management in rice fields and the targeted breeding of new rice varieties be developed," says Planer-Friedrich.
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Agriculture & Food
| 2,020 |
February 10, 2020
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https://www.sciencedaily.com/releases/2020/02/200210133152.htm
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Is it hemp or marijuana? New scanner gives instant answer
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Hemp is technically legal in Texas, but proving that hemp is not marijuana can be a hurdle, requiring testing in a licensed laboratory. So, when a truck carrying thousands of pounds of hemp was recently detained by law enforcement near Amarillo, the driver spent weeks in jail awaiting confirmation that the cargo was legal.
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Stories like that one inspired a team of Texas A&M AgriLife researchers to create a "hemp scanner" that could easily fit in a police cruiser and distinguish hemp and marijuana instantly, without damaging any of the product. The study was published in January in the scientific journal In 2019, Texas lawmakers made a distinction between hemp and marijuana based on the level of THC, or tetrahydrocannabinol, in a plant. THC is the major psychoactive agent in marijuana. If a plant has less than 0.3% THC, it is designated hemp.Both federal and state restrictions on hemp have loosened in recent years. As a result, the value of hemp has skyrocketed, said Dmitry Kurouski, Ph.D., assistant professor of biochemistry and biophysics at the Texas A&M University College of Agriculture and Life Sciences, who led the study. Hemp is rich in compounds that are prized for their medicinal properties and flavor. The most well-known is CBD, or cannabidiol, which is thought to help with pain, anxiety and depression.But farmers wanting to grow valuable hemp plants need a way to know that the plants contain little to no THC. When hemp can be legally grown in Texas later this year, producers will want to know if their plants' THC levels are approaching 0.3%, which would classify the plants as marijuana and therefore illegal to have and grow. An easy test for THC would be a boon for farmers as well as for law enforcement.Kurouski said that the catalyst for creating the hemp scanner was his colleague David Baltensperger, Ph.D., professor of soil and crop sciences at the Texas A&M University College of Agriculture and Life Sciences. Baltensperger had worked with both farmers and police officers and knew about the demand for a better test for THC, Kurouski said.Kurouski's lab was experienced in using a technique called Raman spectroscopy to create quick and noninvasive tests for plant diseases and foods' nutritional content. The technique uses harmless laser light to illuminate structures within materials. Each material's scan is unique, akin to a fingerprint.Kurouski had a hunch that Raman could be used to create a quick and accurate test for THC. A portable Raman scanner had been created for previous studies by lab members Lee Sanchez, a research assistant, and Charles Farber, a graduate student.What was then needed was a way to scan many marijuana and hemp plants in order to search for patterns in how their Raman spectra differed.Testing dozens of samples of marijuana and hemp fell to Sanchez. The testing needed to happen near Denver, where recreational marijuana is legal."Lee Sanchez was the hero who was traveling to Colorado three times, staying there in hotels and driving from one location to another. Most of those locations are old fire stations. They are not fancy greenhouses but old, shaky buildings with plants inside," Kurouski said.Back in Texas, Sanchez and Kurouski analyzed the collected spectra. A statistical analysis method found seven regions in the spectra that differed slightly among marijuana and hemp varieties, a high-tech version of the "spot the difference" brain teaser. Taken together, the readout in these seven regions distinguishes hemp and marijuana with 100% accuracy."We know plants from A to Z in terms of their spectroscopic signature," Kurouski said. "But when we saw such a crystal-clear picture of THC that appeared in one second of spectral acquisition, that was mind-blowing."Now that Kurouski's team has demonstrated its quick, noninvasive test for THC, they are looking to collaborate with industry to mass-produce their hemp scanner. Mass production could feasibly begin in two or three years, Kurouski said.The team also aims to create a similar test for CBD. Farmers looking to grow hemp may want to know the amount of CBD in their plants to better estimate their value.The study also uncovered the scanner's ability to distinguish among different varieties of hemp and marijuana. In the changing legal landscape, there are thousands of varieties of cannabis, many of questionable quality."Our colleagues, the farmers, were positively surprised that we could identify the variety with 98% accuracy," Kurouski said. "That blew them away."
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Agriculture & Food
| 2,020 |
February 10, 2020
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https://www.sciencedaily.com/releases/2020/02/200210104106.htm
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Model shows how to make on-farm sustainable energy projects profitable
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Researchers have developed a model that could boost investment in farm-based sustainable energy projects by allowing investors to more accurately predict whether a project will turn a profit. The model improves on earlier efforts by using advanced computational techniques to address uncertainty.
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"Converting animal waste into electricity can be profitable for farmers while also producing environmental benefits, such as reducing greenhouse gas emissions," says Mahmoud Sharara, lead author of a paper on the work and an assistant professor of biological and agricultural engineering at North Carolina State University. "However, farmers cannot always finance these projects, and projects aren't always a profitable enterprise for a single farm."One way to address this is to develop cooperative anaerobic digestion systems that make use of waste from multiple farms," Sharara says. "Two of the big questions surrounding this sort of project are: Where do you build the cooperative system? And how can you tell whether it will be profitable?"To that end, the researchers developed a computational model that tells users how to maximize the economic return on anaerobic digestion systems. Specifically, it tells users where a system should be located, what its capacity should be and how large a geographic area it should serve.The model accounts for a variety of known factors, such as which species a farm is raising, the size of each farm and where each farm is located. But what sets the model apart is the way it accounts for uncertainty.For this work, the researchers identified 13 key sources of uncertainty that can affect the profitability of an anaerobic digester system.For example, one way these systems make money is by converting animal waste into biogas, using that gas to produce electricity, and then selling the electricity. Therefore, one key variable in predicting the profitability of a system is the future sale price of electricity. And while the future price of electricity is uncertain, you can draw on historical data or market forecasts to estimate a price range.The same is true for other sources of uncertainty. For instance, the efficiency of an anaerobic digester is uncertain, but you can predict that the digester's performance will fall within a certain range.This is where the model comes in.The researchers designed the model to run repeated simulations that account for variation in each area of uncertainty. For example, what does profitability look like when electricity prices and digester efficiency are both high? What if they're both low? And so on. By running all of these simulations for different site locations, capacities and service areas, the model can tell users which combination of factors would generate the most profit.The research team demonstrated the model with case studies of anaerobic digester systems for dairy farms in two regions of Wisconsin."The case studies were a good sanity check for us, and highlighted the viability and utility of the model," Sharara says."Ultimately, we think this will spur investment in these projects, which will be good for both farmers and the environment."The model is available now, and the researchers are interested in packaging it in a format that would be easier to use and distribute."We're also hoping to work more closely with anaerobic digester system developers to fine-tune our assessment of the costs related to these systems," Sharara says. "And, ultimately, we'd like to expand our work to account for efforts to use the solids left behind after anaerobic digestion -- such as projects that convert these solids into marketable fertilizer."
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Agriculture & Food
| 2,020 |
February 10, 2020
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https://www.sciencedaily.com/releases/2020/02/200210074240.htm
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Scientists warn humanity about worldwide insect decline
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Engaging civil society and policy makers is essential for the future and mutual well-being both of people and insects. In addition to mitigating climate change, an important aspect of the solution involves setting aside high-quality and manageable portions of land for conservation, and transforming global agricultural practices to promote species co-existence.
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Humanity is pushing many ecosystems beyond recovery. As a consequence, unquantified and unquantifiable insect extinctions are happening every day. Two scientific papers by 30 experts from around the world discuss both the perils and ways to avoid further extinctions, intending to contribute towards a necessary change of attitude for humanity's own sake."It is surprising how little we know about biodiversity at a global level, when only about 10 to 20 per cent of insect and other invertebrate species have been described and named. And of those with a name, we know little more than a brief morphological description, maybe a part of the genetic code and a single site where it was seen some time ago," says Pedro Cardoso, from the Finnish Museum of Natural History Luomus, University of Helsinki, Finland.Habitat loss, pollution -- including harmful agricultural practices, invasive species that do not encounter borders, climate change, overexploitation and extinction of dependent species all variably contribute to documented insect population declines and species extinctions."With species loss, we lose not only another piece of the complex puzzle that is our living world, but also biomass, essential for example to feed other animals in the living chain, unique genes and substances that might one day contribute to cure diseases, and ecosystem functions on which humanity depends," confirms Cardoso.The ecosystem functions he mentions include pollination, as most crops depend on insects to survive. Additionally, decomposition, as they contribute to nutrient cycling, as well as many other functions for which we have no technological or other replacement.The researchers also suggest possible practical solutions based on existing evidence gathered from around the world, which would help to avoid further insect population loss and species extinctions. These include actions such as setting aside high-quality and manageable portions of land for conservation, transforming global agricultural practices to promote species co-existence, and mitigating climate change.Above all, communicating and engaging with civil society and policy makers is essential for the future and mutual well-being both of people and insects."While small groups of people can impact insect conservation locally, collective consciousness and a globally coordinated effort for species inventorying, monitoring and conservation is required for large-scale recovery" says Michael Samways, Distinguished Professor at Stellenbosch University, South Africa.Ideas to help insects2. Plant native plants; many insects need only these to survive.3. Avoid pesticides; go organic, at least for your own backyard.4. Leave old trees, stumps and dead leaves alone; they are home to countless species.5. Build an insect hotel with small horizontal holes that can become their nests.6. Reduce your carbon footprint; this affects insects as much as other organisms.7. Support and volunteer in conservation organizations.8. Do not import or release living animals or plants into the wild that could harm native species.9. Be more aware of tiny creatures; always look on the small side of life.
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Agriculture & Food
| 2,020 |
February 7, 2020
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https://www.sciencedaily.com/releases/2020/02/200207153632.htm
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No clear path for golden rice to reach consumers
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Heralded as a genetically modified crop with the potential to save millions of lives, Golden Rice has just been approved as safe for human and animal consumption by regulators in the Philippines. The rice is a beta carotene-enriched crop that is intended to reduce Vitamin A deficiency (VAD), a health problem in very poor areas.
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But a new study finds that most families at risk for VAD can't grow Golden Rice themselves, and most commercial farmers won't grow it either."Many families with Vitamin A deficient kids don't even have rice land to plant it," said Glenn Davis Stone, professor of sociocultural anthropology and environmental studies in Arts & Sciences at Washington University in St. Louis and co-author of a new paper in the journal The regulatory approval in the Philippines is a landmark for the scientists who developed Golden Rice for nutritional purposes. It is the first such approval in the developing world. But even after nearly three decades of development, Golden Rice is still beset by problems, according to Stone.Golden Rice still has to be approved for commercial sale, and it still needs a company to grow marketable quantities of seed. And even then, Stone argues, there is no clear path for the rice to get to poor children.Stone, an internationally recognized expert on the human side of global agricultural trends, was an early advocate for keeping an open mind about 'humanitarian' GMO crops, such as Golden Rice. Since 2013, he has directed a major Templeton Foundation-funded research project on rice in the Philippines.Stone's new study is based on surveys and interviews of more than 115 rice farmers in the Nueva Ecija region, considered part of the 'rice bowl' of the Philippines.Writing in the Feb. 7 issue of The Conversation, Stone and his study co-author Dominic Glover, a rice researcher at the Institute for Development Studies at the University of Sussex, suggest that backers of Golden Rice -- and even some economists who have tried to project its health impacts -- have made certain flawed assumptions about farmers' willingness to plant the crop."The old claim, repeated again in a recent book, that Golden Rice was 'basically ready for use in 2002' is silly," Stone and Glover wrote. "As recently as 2017, IRRI made it clear that Golden Rice still had to be 'successfully developed into rice varieties suitable for Asia, approved by national regulators, and shown to improve vitamin A status in community conditions.'"The Philippines has managed to cut its childhood VAD rate in half with conventional nutrition programs. If Golden Rice appears on the market in the Philippines by 2022, it will have taken over 30 years of development to create a product that may not affect vitamin levels in its target population, and that farmers may need to be paid to plant."
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Agriculture & Food
| 2,020 |
February 5, 2020
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https://www.sciencedaily.com/releases/2020/02/200205084209.htm
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Bumble bees prefer a low-fat diet
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Bees are an important factor for our environment and our sustenance. Without insect pollination, many plant species -- including various crops -- cannot reproduce. "Bee mortality therefore affects food supply for human beings," stated Professor Sara Leonhardt, who specializes in plant-insect interactions. All of the worldwide more than 20,000 bee species need to be considered. Among these, bumble bees are of particular importance besides the famous honey bee.
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"Bees obtain most of their nutrients from their main food sources, which are nectar and pollen. While nectar is mainly a source of carbohydrates, pollen contains most of the other necessary nutrients: proteins, fat, minerals and vitamins. Until today, most bee researchers assumed that bees, like other herbivores, mainly consider the protein content when choosing their food," Professor Leonhardt explained.Using a two-step mechanistical approach that included learning and feeding experiments, the group established a new way to literally keep a close eye on the feeding habits of insects.Which nutrients can bumble bees taste in pollen? As a first step, learning experiments helped the scientists to establish the bumble bees' preference for certain nutrients -- in this case fat and protein.Fabian Rüdenauer, main author of the study, explained: "We are focusing on fatty and amino acids, which represent the two essential pollen macro nutrients and which are likely to be perceived and thus tasted by bees."In this context, a small amount of fatty acids was added to pollen to increase its fat content. The researchers found that bumble bees could clearly differentiate between normal pollen and pollen with increased fat content and did show a clear preference for normal pollen. Surprisingly, the bumble bees made no clear distinction when the pollen amino acid content was altered in the same way.Which nutrients actually affect the bumble bees' foraging behavior and what are the consequences for their survival and reproductive capabilities? Those were the central questions guiding the subsequent feeding experiments."The more fat the pollen contained, the less the bumble bees consumed that pollen," Leonhardt concluded. Bumble bees actually accepted death over having to consume the high-fat pollen. The work group therefore concluded that fat in pollen adversely affects the bumble bees' reproductive capabilities and survival, which is why it is being avoided.Similar to the learning experiment, variations in the amino acid content of pollen did not affect the bees' feeding habits, survival or reproduction."Our study highlights the importance of fat for foraging bumble bees. It also shows that there is a correlation between nutrient perception, nutritional regulation and reproductive fitness," stated Dr. Johannes Spaethe from the University of Würzburg, who also led the study. "The bees can taste what is good for them and collect their food accordingly," said Leonhardt, summarizing the results.Currently, the researchers are creating a dataset on pollen nutritional chemistry in order to obtain an overview across the wide spectrum of different plant species. They are also examining the nutritional needs of other species of bees. "In the future, this may lead to better understanding the effect of variation in flowering plant species on bees, and it may improve protective measures such as flower strips in agricultural landscapes," predict the researchers.
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Agriculture & Food
| 2,020 |
February 4, 2020
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https://www.sciencedaily.com/releases/2020/02/200204121457.htm
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Wasps' gut microbes help them -- and their offspring -- survive pesticides
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Exposure to the widely used pesticide atrazine leads to heritable changes in the gut microbiome of wasps, finds a study publishing February 4 in the journal
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"After a single exposure to some chemicals -- xenobiotics -- the gut microbiome can be permanently affected," says senior study author Robert Brucker of Harvard University. "Exposure can have lasting changes to future generations even after an exposure risk is eliminated."Agrochemicals used to fertilize crops and control pest species pose one of the greatest xenobiotic exposure risks to many organisms. The herbicide atrazine is the second most sold pesticide globally. Previous studies have shown that atrazine has multiple effects on host animals, but little is known about how environmental xenobiotic chemicals change the gut microbiome.To address this question, Brucker and his team examined the impact of acute or continuous subtoxic atrazine exposure on the model wasp species In the first generation, exposure to 300 ppb of atrazine altered the bacterial community structure of wasps, resulting in an increase in microbiome diversity and overall bacterial load. Even exposure to a lower concentration of 30 ppb of atrazine caused a microbiome shift that persisted across successive generations.When the researchers switched the offspring of the atrazine-exposed population to a non-atrazine diet for six generations, they observed that the bacterial microbiome remained most similar to that of the parents. "This result indicates that the disruption to the microbiome after acute exposure to atrazine is inherited across generations, even after exposure is removed," Brucker says.In addition, exposure to 30 ppb of atrazine over 36 generations reduced atrazine-induced mortality by a factor of ten, and also increased tolerance to the herbicide glyphosate, despite no prior exposure to the compound. After 25 generations, a subset of the wasp population was switched to a non-atrazine diet. Remarkably, atrazine tolerance was inherited and sustained through the 36th generation.Other experiments showed that the increased atrazine tolerance of wasps is related to their altered microbiome. For example, maintaining wasps in a germ-free environment eliminated atrazine tolerance. On the other hand, transplanting the microbiome of atrazine-exposed wasps to non-exposed wasps conferred atrazine resistance."Overall, we demonstrate that resistance to multiple pesticides can arise in a population that is exposed to sub-toxic concentrations, that the microbiome facilitates this resistance, and that it provides resistance against other pesticides to which the host animal has never been previously exposed," Brucker says.In particular, atrazine exposure increased the densities of the rare gut bacteria "The shift in the microbial community following continuous atrazine exposure may be providing host resistance via detoxification, representing a rapid route of ecological adaptation for the host to cope with novel toxic challenges," Brucker says. "Pesticide exposure causes functional, inherited changes in the microbiome that should be considered when assessing xenobiotic exposure and as potential countermeasures to toxicity."Taken together, the findings demonstrate that atrazine exposure can alter the microbial community of wasps, which can in turn directly impact host fitness across generations. Even though "These results could reflect microbe-host-associated changes in response to xenobiotic exposure in wild honey bee population, similar to what we describe in In future studies, Brucker and his team plan to examine which loci have been under selection, and how they might be implicated in toxin resistance or microbiome regulation. They are also planning on leveraging their findings to develop probiotics for honey bees to reduce multi-pesticide exposure risk."We can use our understanding of the host-microbiome interaction to reduce the exposure risk of all pesticides, for example, by using bacteria for cleaning up spills or as probiotics for at-risk humans, or off-target plants and animals," Brucker says. "Further host-microbiome studies of multi-generational exposure to xenobiotic compounds are needed, especially in light of the increased risk of xenobiotic exposure to humans, plants, animals, fungi, and bacteria across the globe."
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Agriculture & Food
| 2,020 |
January 31, 2020
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https://www.sciencedaily.com/releases/2020/01/200131114727.htm
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Not-so-dirty birds? Not enough evidence to link wild birds to food-borne illness
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When food makes people sick, some blame birds because they hang around farms, and their feces can contain
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But a recent Washington State University study published in The perceived risk of wild birds can impact their survival, said Olivia Smith, lead author on the study and a recent WSU Ph.D. graduate."Farmers are being encouraged to remove wild bird habitat to make their food safer, but it doesn't appear that these actions are based on data," Smith said. "When you restrict birds from agricultural settings, you are doing something that can lead to their decline."Bird populations have been falling rapidly in recent decades. Scientists estimate that since 1970, North America has lost more than three billion birds. In light of this, the WSU researchers highlighted the need for more definitive research before destroying habitat and banning birds from fields in the name of food safety.Smith and her colleagues, WSU Associate Professor Jeb Owen and Professor William Snyder, analyzed data for In their review, the researchers found only one study definitively linking wild birds to food-borne illness outbreaks: a case where sandhill cranes spread Campylobacter on fresh peas in an outbreak that sickened nearly 100 people in Alaska in 2008.The most studied birds in relation to these pathogens were ducks, geese as well as two non-native species house sparrows and European starlings that tend to swarm on feed lots and can contaminate the food and water used for cattle. Yet there's a huge gap in knowledge about many other common native species that are often around agricultural crops including American robins.Only 3% of the studies that the researchers analyzed looked at the entire transmission process from bird to plant to human. The majority simply tested bird feces to see if the bacteria were present or not.In order for the bacteria to make people sick, the bird needs to get pathogenic strains of "Birds do carry bacteria that can make people sick, but from our review of the scientific studies, it's unclear how big of a risk they are," Smith said.
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Agriculture & Food
| 2,020 |
January 30, 2020
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https://www.sciencedaily.com/releases/2020/01/200130144335.htm
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Bacteria engineered to protect bees from pests and pathogens
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Scientists from The University of Texas at Austin report in the journal
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An increasing number of honey bee colonies in the U.S. have seen the dwindling of their adult bees. According to a national survey, beekeepers lost nearly 40% of their honey bee colonies last winter, the highest rate reported since the survey began 13 years ago.The engineered bacteria live in the guts of honey bees and act as biological factories, pumping out medicines protecting the bees against two major causes of colony collapse: Varroa mites and deformed wing virus. The researchers believe their method could one day scale up for agricultural use because the engineered bacteria are easy to grow, inoculating the bees is straightforward and the engineered bacteria are unlikely to spread beyond bees."It has direct implications for bee health," said Nancy Moran, a professor of integrative biology and the primary investigator on the study."This is the first time anyone has improved the health of bees by genetically engineering their microbiome," added Sean Leonard, a graduate student and first author of the study.Varroa mites and deformed wing virus often come together; as the mites feed on bees, they can spread the virus, while also weakening the bees and making them more vulnerable to pathogens in the environment.To address each problem, the team engineered one strain of bacteria to target the virus and another for the mites. Compared with control bees, the bees treated with the strain of bacteria targeting the virus were 36.5% more likely to survive to day 10. Meanwhile, Varroa mites feeding on another set of bees treated with the mite-targeting strain of bacteria were about 70% more likely to die by day 10 than mites feeding on control bees.According to the American Beekeeping Federation, honey bees contribute nearly $20 billion each year to the value of U.S. crop production, and they play an enormous role in global food production. Without honey bees, dozens of crops, from almonds to berries to broccoli, would either vanish or produce significantly less food.Like humans, honey bees have an ecosystem of bacteria in their guts called a microbiome and also an antiviral defense mechanism called RNA interference (RNAi) that helps the body fight off certain viruses, called RNA viruses. When an RNA virus is introduced, it produces molecules called double-stranded RNAs that a healthy cell detects, triggering an RNAi immune response."You usually only get signs of these molecules when an RNA virus is replicating," Moran said. "It's a signal that this might be an evil thing and you should attack it."To promote a helpful RNAi response to viruses in bees -- and trigger a lethal RNAi response in the mites -- the team introduced modified bacteria to hundreds of bees in a laboratory setting. Sprayed with a sugar water solution containing the bacteria, the bees groomed one another and ingested the solution. The team found inoculating young worker bees with the engineered bacteria led the bees' immune systems to be primed to protect them against deformed wing virus, which is an RNA virus, and caused the mites' own immune systems to fight against and ultimately kill them.While the experiments occurred under strict biocontainment protocols used with genetic engineering, Moran said, even absent such protocols, the risk of the engineered bacteria escaping into the wild and infecting other insects -- and thereby conferring some anti-pest or anti-pathogen superpowers -- is very low. The type of bacteria used are highly specialized to live in the bee gut, can't survive for long outside of it and are protective for a virus that strikes only bees. Still, further research will be needed to determine the effectiveness and safety of the treatments in agricultural settings.Another benefit of the approach is for researchers to use it as a tool in studying bee genetics. The engineered bacteria can knock down specific bee genes, enabling insights into the workings of the bee genome, and possibly enabling new breeding strategies to produce more robust bee colonies.
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Agriculture & Food
| 2,020 |
January 30, 2020
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https://www.sciencedaily.com/releases/2020/01/200130115428.htm
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Solving the riddle of strigolactone biosynthesis in plants
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Strigolactones (SLs) are a class of chemical compounds found in plants that have received attention due to their roles as plant hormones and rhizosphere signaling molecules. They play an importantrole in regulating plant architecture, as well as promoting germination of root parasitic weeds (*1) that have great detrimental effects on plant growth and production.
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This study was conducted as part of the SATREPS(*2)(Science and Technology Research Partnership for Sustainable Development) program by Dr. Wakabayashi, Prof. Sugimoto and their colleagues at the Graduate School of Agricultural Science, Kobe University, in collaboration with researchers from the University of Tokyo and Tokushima University. They discovered the orobanchol synthase responsible for converting the SL carlactonoic acid, which promotes symbiotic relationships with fungi, into the SL orobanchol, which causes root parasitic weeds to germinate.By knocking out(*3) the orobanchol synthase gene using genome editing, they succeeded in artificially regulating SL production. This discovery will lead to greater understanding of the functions of each SL and enable the practical application of SLs in the improvement of plant production.The results of this study were published in the International Scientific Journal >Strigolactones are known to have various functions such as the development of plant architecture, promoting mutually beneficial mycorrhizal relationships with fungi and serving as germination signals for root parasitic weeds.>Strigolactones are classified into canonical and non-canonical SLs based on their chemical structures. Canonical SLs have an ABC ring, whereas non-canonical SLs have an unclosed BC ring.>This study discovered the synthase gene responsible for converting the non-canonical SL carlactonoic acid into the canonical SL orobanchol.>The group succeeded in generating tomato plants with the synthase gene knocked out in which carlactonoic acid (CLA) accumulated and orobanchol production was prevented. The germination rate of root parasitic weeds was lower for these knock out plants.Strigolactones (SL) are a class of chemical compounds that were initially characterized as germination stimulants for root parasitic weeds. SLs have also received attention for their other functions. They play an important role in controlling tiller bud outgrowth and also in promoting mycorrhizal symbiosis in many land plants, whereby plants and fungi mutually exchange nutrients.Up until now, around 20 SLs have been isolated; with differences in stereochemistry in the C ring and modifications in the A and/or B rings. In recent years, SLs with unclosed BC rings have been discovered. Currently, SLs with a closed ABC ring are designated as canonical SLs, whereas SLs with an unclosed BC ring are non-canonical SLs. However, it is not clear which compounds function as hormones and which compounds function as rhizosphere signals.If SL production could be suppressed, plants would induce the germination of fewer root parasitic weeds and their adverse effects on crop production would be mitigated. By increasing SL production, on the other hand, plant nutrition would be improved through the promotion of relationships with mycorrhizal fungi. Furthermore, manipulation of the endogenous levels of SL would control plant architecture above ground. Understanding the functions of individual SLs would lead to the development of technology to artificially control plant architecture and the rhizosphere environment. Consequently, there is much interest in how these SLs are biosynthesized.It has been elucidated that SLs are biosynthesized from?-carotene. Four enzymes are involved in conversion of?-caroteneto carlactonoic acid (CLA), a common intermediate of SL biosynthesis. In This research group had isolated orobanchol from cowpea root exudates and determined the structure. From metabolic experiments using cowpea, it was predicted that cytochrome P450(*4)would be involved in the conversion of CLA into orobanchol. In this study, cowpea plants were grown in phosphate rich and poor conditions, where orobanchol production was restricted and promoted, respectively. The genes expressed in the roots of plants in both conditions were comprehensively compared. The group screened for CYP genes whose expression correlated with orobanchol production, expressed them as recombinant proteins, and performed an enzyme reaction assay.From these results, it was understood that the VuCYP722C enzyme catalyzed the conversion of CLA to orobanchol. Furthermore, the SlCYP722C gene, a homolog (*5) of VuCYP722C in tomato was confirmed to be an orobanchol synthase gene. The SlCYP722C gene was knocked out (KO) in tomato plants using genome editing. In contrast to the wild type (control) tomato plants, orobanchol was not detected in root exudates of the KO plants, with CLA being detected instead.Thus, the research group proved that SlCYP722C is the orobanchol synthase in tomato that converts the non-canonical SL CLA into the canonical SL orobanchol. The architecture of the KO and wild-type plants was comparable (Photo 1). This demonstrated that orobanchol doesn't control plant architecture in tomato plants. It is thought that these KO tomato plants would still be able to benefit from mycorrhizal fungi, as the activity of CLA against the hyphal branching of the fungi was comparable with that of canonical SLs. Furthermore, it was found that the germination rate of the root parasitic weed This research group succeeded in preventing the synthesis of the major canonical SL orobanchol and accumulating the non-canonical SL carlactonoic acid. The same method can be utilized to elucidate the genes responsible for the biosynthesis of other canonical SLs. Further understanding of the functions of various SLs would allow plants to be manipulated in order to maximize their performance under adverse cultural conditions. Root parasitic weeds detrimentally affect not only tomato but a wide range of other crops including species of Solanaceae, Leguminoceae, Cucurbitaceae and Poaceae. These results will lead to the development of research to alleviate the damage inflicted by root parasitic weeds and increase food production worldwide.1. Root parasitic weeds These are weeds that connect with other plants underground and feed off them. Root parasitic weeds can cause great damage to food crops. For example, 2. SATREPS SATREPS is a Japanese government program that promotes international joint research, co-sponsored by JST (Japan Science and Technology agency) and JICA (Japan International Cooperation Agency). It aims to find solutions for global issues by promoting 3-5 year research collaborations between researchers from Japan and developing countries. JST provides funding for research within Japan and outside the partnership country. If funding is necessary for the partnership country, JICA provides ODA within the framework of technical cooperation projects. The two organizations work together utilizing their respective strengths; JST's expertise in funding domestic research projects and JICA's expertise in technical cooperation in developing countries.3. Genome editing and gene knock out Genome editing is a type of genetic engineering which involves making specific modifications to the DNA of a living organism. The DNA is cut at a specific sequence by an engineered nuclease. This cut is repaired through non-homologous end-joining by the cell, resulting in a change to the targeted sequence. This allows small additions or deletions to be made to the DNA and for the function of a specific gene to be removed (knock out).4. Cytochrome P450 Part of the hemoprotein family. It is called "P450" because the maximum wavelength of the enzymes' absorption is 450 nm when in its reduced state and complexed with carbon monoxide. The existence of cytochrome P450 has been confirmed in a variety of organisms. These hemoproteins are involved in the synthesis of hormones and secondary metabolites, and drug metabolism.5. Homolog A gene that resembles another gene due to shared ancestry.This research was supported by the JST/JICA SATREPS program (JPMJSA1607) 'Improvement of Food Security in Semi-arid Regions of Sudan through Management of Root Parasitic Weeds (Striga)'(Principal Investigator: Professor SUGIMOTO Yukihiro), and the JSPS KAKENHI (19H02897) for the 'Elucidation of strigolactone BC ring formation mechanism aiming at elucidation of the active ingredient as branching inhibitory hormone' (PI: Professor SUGIMOTO Yukihiro) among others.
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Agriculture & Food
| 2,020 |
January 30, 2020
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https://www.sciencedaily.com/releases/2020/01/200130081604.htm
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Biological diversity as a factor of production
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The main question addressed by the study is: Does greater biodiversity increase the economic value of managed ecosystems? "We have found that the possible relationships between economic value and biodiversity are varied," says Professor Thomas Knoke, Head of the Institute of Forest Management at the TUM School of Life Sciences Weihenstephan.
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Even a layman can guess the main purpose of single-species timber plantations: economic benefit through the sale of wood. But forests have a number of functions. They serve as home to a variety of animal and plant species, function as a source of wood as a raw material, have a protective function such as protecting the soil and helping combat global warming and serve recreational purposes as well.It is common ecological knowledge that the more biodiverse a forest is, the higher the productivity will be. However, the researchers found that "after you have reached a certain mix of trees, adding new species no longer produces significant economic benefits to people." What counts here are the characteristics of the species of trees inhabiting the forest as not every tree has the same value."The different functions of an ecosystem never stand to an equal degree in positive relation to biodiversity," explains Carola Paul, University of Göttingen, who until recently was a member of Thomas Knoke's team. If you were to compile all functions of an ecosystem, you would find a mathematical maximum in terms of its value.The team found that, "maximizing biodiversity at the level of the ecosystem does not maximize economic value in most cases." This particularly holds true if compromises have to be made between different purposes or different economic yields and risks. In such cases, applying a medium level of biological diversity proves most beneficial.The more diverse the plants in an ecosystem are, the better the situation is in terms of risk diversification. This affects the variability of cash value of the ecosystem. The research shows that risk premiums can be lowered just by making a minor change to the level of biodiversity. Risk premium is the reward that a risk-averse person requires to accept a higher risk.The researchers identified high value potential in biodiversity particularly in connection with the avoidance of social costs. These costs are borne by the public such as diseases caused by air pollution. In its mathematical calculations of these social costs, the study argues that more diverse, mixed agriculture and forest management systems pay off. "Biodiverse ecosystems require less pesticides and fertilizer," explains Thomas Knoke."Based on theoretical considerations and empirical evidence, we have found that ecosystems with several, but in all actuality relatively few, plant species can produce more economic benefits than those with only one species as well as those with a large number of species," the scientist summarizes.According to the research, biodiversity and ecosystem functionality rarely create a consistent upward curve. Instead, the team found empirical and theoretical evidence of strictly concave or strictly convex relationships between biodiversity and economic value.These findings in no way indicate that mega biodiverse ecosystems are not worth protecting. Instead they show that economic arguments alone are not sufficient when talking about these biodiversity "hot spots."What the relationships do highlight are the economic benefits that even a minor increase in biodiversity could have in the agricultural sector. When it comes to forests, the study shows that it is possible to manage a stable forest that serves a variety of functions with four to five species of trees. The relationships identified in the study can therefore be of considerable value in land use planning going forward.
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Agriculture & Food
| 2,020 |
January 29, 2020
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https://www.sciencedaily.com/releases/2020/01/200129174530.htm
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Prescribed burns benefit bees
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Freshly burned longleaf pine forests have more than double the total number of bees and bee species than similar forests that have not burned in over 50 years, according to new research from North Carolina State University.
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For many forests, fire is as essential as rainfall. But while several studies have outlined the benefits of human-controlled prescribed burns on forest ecosystems, little was understood about how prescribed burns, or fires in general, may impact pollinators."There is global concern about the decline of insects in general, and pollinators in particular, so it's really important for land managers to understand how prescribed fire affects insect communities," says Elsa Youngsteadt, co-author of a paper on the work and an assistant professor in NC State's Department of Applied Ecology."Given the importance of fire in maintaining longleaf pine ecosystems overall, you would expect it to be good for the region's native bees. But it's also easy to imagine small bees and their nests, especially nests in twigs and stems, just getting incinerated. We weren't sure where we would find the most robust pollinator community."NC State researchers worked with the Walthour-Moss Foundation's longleaf pine savannah reserve, which was established to protect this endangered pine. The reserve regularly burns 90% of its plots in 3-year cycles, while the remaining 10% of plots have not been burned for at least 50 years. This provided an ideal opportunity to compare bee abundance and diversity between unmanaged and managed ecosystems."The southeastern U.S. has some of the highest lightning strike rates in the world, which used to contribute to low-intensity fires passing through the longleaf pine savannas every 2 or 3 years," Youngsteadt says. "But agriculture, development, and logging fragmented this landscape and blocked the movement of fire."For this study, researchers placed bee "traps" at 16 sites: four that had been burned the year of sampling, four that had been burned one year before sampling, four that had been burned two years before sampling, and four unburned control sites.The researchers found that burned sites supported 2.3 times more total pollinators than plots that had not burned in 50 years. Burned sites also had 2.1 times as many different bee species as unburned sites. Within those burned areas, bee abundance and diversity tended to be greatest at sites that were most recently burned, and this abundance and diversity decreased with time since the last fire.But why?Fires maintain openings in the forest canopy, reduce ground cover and release nutrients into soils at the same time, creating the perfect environment for large blooms, increasing the flower resources pollinators rely on. The study also found that the low-intensity prescribed burns did not reduce the amount of nesting material for above-ground nesting pollinators, and the abundance of above-ground nesting pollinators was not impacted by the fires. Meanwhile, below-ground nesting species appeared to benefit from the increased access to bare soil."It's great news that prescribed fire, as currently used in longleaf pine savannas, is helping to support the pollinator community," Youngsteadt says. "But there's still a lot to learn. For example, the fires in this study were set in the winter, but many land managers use summer burns. Knowing the effects of fire in different seasons will be an important next step, as will knowing the optimal area of land to burn at any one time."
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Agriculture & Food
| 2,020 |
January 29, 2020
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https://www.sciencedaily.com/releases/2020/01/200129174528.htm
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Speedy recovery: New corn performs better in cold
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Nearly everyone on Earth is familiar with corn. Literally.
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Around the world, each person eats an average of 70 pounds of the grain each year, with even more grown for animal feed and biofuel. And as the global population continues to boom, increasing the amount of food grown on the same amount of land becomes increasingly important.One potential solution is to develop crops that perform better in cold temperatures. Many people aren't aware that corn is a tropical plant, which makes it extremely sensitive to cold weather. This trait is problematic in temperate climates where the growing season averages only 4 or 5 months -- and where more than 60% of its 1.6 trillion pound annual production occurs.A chilling-tolerant strain could broaden the latitudes in which the crop could be grown, as well as enable current farmers to increase productivity.A group of researchers led by David Stern, president of the Boyce Thompson Institute, have taken a step closer to this goal by developing a new type of corn that recovers much more quickly after a cold snap. Stern is also an adjunct professor of plant biology in Cornell University's College of Agriculture and Life Sciences.The research is described in a paper published online in This work built on research published in 2018, which showed that increasing levels of an enzyme called Rubisco led to bigger and faster-maturing plants. Rubisco is essential for plants to turn atmospheric carbon dioxide into sugar, and its levels in corn leaves decrease dramatically in cold weather.In the latest study, Stern and colleagues grew corn plants for three weeks at 25°C (77°F), lowered the temperature to 14°C (57°F) for two weeks, and then increased it back up to 25°C."The corn with more Rubisco performed better than regular corn before, during and after chilling," said Coralie Salesse-Smith, the paper's first author. "In essence, we were able to reduce the severity of chilling stress and allow for a more rapid recovery." Salesse-Smith was a Cornell PhD candidate in Stern's lab during the study, and she is now a postdoctoral researcher at the University of Illinois.Indeed, compared to regular corn, the engineered corn had higher photosynthesis rates throughout the experiment, and recovered more quickly from the chilling stress with less damage to the molecules that perform the light-dependent reactions of photosynthesis.The end result was a plant that grew taller and developed mature ears of corn more quickly following a cold spell.Steve Reiners, a co-team leader for Cornell Cooperative Extension's vegetable program, says that sweet corn is a major vegetable crop in New York, worth about $40-$60 million annually. He notes that many New York corn growers plant as soon as they can because an early crop commands the highest prices of the season.Reiners, who was not involved in the study, is also a professor of horticulture at Cornell."The corn we developed isn't yet completely optimized for chilling tolerance, so we are planning the next generation of modifications," said Stern. "For example, it would be very interesting to add a chilling-tolerant version of a protein called PPDK into the corn and see if it performs even better."The researchers believe their approach could also be used in other crops that use the C4 photosynthetic pathway to fix carbon, such as sugar cane and sorghum.Co-authors on the paper include researchers from The Australian National University in Canberra.The study was supported by the U.S. Department of Agriculture's National Institute of Food and Agriculture (2016-67013-24464) and Australian Research Council Centre of Excellence for Translational Photosynthesis (CE1401000015).
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Agriculture & Food
| 2,020 |
January 29, 2020
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https://www.sciencedaily.com/releases/2020/01/200129174508.htm
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Microscopic partners could help plants survive stressful environments
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Tiny, symbiotic fungi play an outsized role in helping plants survive stresses like drought and extreme temperatures, which could help feed a planet experiencing climate change, report scientists at Washington State University.
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Recently published in the journal While some microscopic fungi and bacteria cause disease, others live in harmony with plants, collecting water and nutrients in exchange for carbohydrates, or changing plants' internal and external environment in ways that help plants grow.These benefits help plants tolerate stresses that come from their environment. Dubbed abiotic stresses, challenges such as drought, extreme temperatures, and poor, toxic, or saline soils are among the leading causes of crop loss and decreasing farm productivity."Plants' abilities to tolerate stress are impacted by the bacteria and fungi that live on or inside them and make up the plant microbiome," said Porter, assistant professor in the School of Biological Sciences. "Just like how microbes in our digestive system help keep us healthy, microbes play an incredibly important role in plant health."Setting out to measure how beneficial microbes affect plants under both normal conditions and stress, Porter and Friesen reviewed 89 research experiments ranging from common Northwest food crops to wild species.Working with colleagues at Michigan State University and WSU, they compared five different classes of symbiotic bacteria and fungi that live on, in, and around plant roots, under stresses that included fungal diseases, grazing by animals and microscopic worms, heavy metal contamination, and drought, cold, and saline soils. Then, they tallied the effect on plant growth, biomass and yield.Results showed that while beneficial bacteria are more helpful in normal conditions, symbiotic fungi provide added benefits during crises."Stress makes these fungi even more important to plants, which we think is really interesting," said Friesen, assistant professor in the Department of Plant Pathology.Particularly beneficial were arbuscular mycorrhizal fungi, which colonize plant roots, provide water, and enhance uptake of nitrogen, phosphorus, and other micronutrients in the soil."Should growers want to foster the plant microbiome for stress resistance, our study suggests they should really focus on fungi," Porter said. "These beneficial microbes could be the key to helping us grow more food in the coming decades."With earth's population predicted to top 9 billion by 2050, scientists predict that current crop yields will need to double."As we expand where we grow crops, we're using marginal areas that are more stressful for plants," Porter said. "And as our climate changes, that creates stress for plants."Maren and I wanted to be forward-looking," she added. "We wanted to find evidence of how we can best use beneficial microbes to mitigate the stresses that we know are coming."Microbes offer a more sustainable tool for stress tolerance than applying hormones or chemicals, noted Friesen."Farmers are now having challenges with pathogens no longer responding to chemical treatments," she said. "There's already a lot of interest in scientific and industry circles in identifying and harnessing microbial solutions to agricultural problems. This study gives us ideas about where to look."
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Agriculture & Food
| 2,020 |
January 29, 2020
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https://www.sciencedaily.com/releases/2020/01/200129143349.htm
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Plants manipulate their soil environment to assure a steady supply of nutrients
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The next time you're thinking about whether to cook dinner or order a pizza for delivery, think of this: Plants have been doing pretty much the same thing for eons.
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Researchers in Rice University's Systems, Synthetic and Physical Biology program detailed how plants have evolved to call for nutrients, using convenient bacteria as a delivery service.Their open-access report in When nitrogen is present and available, plants don't need to order in. Their ability to sense the presence of a nearby slow-release nitrogen source, organic carbon, is the key."It's a gorgeous example of evolution: Plants change a couple of (oxygen/hydrogen) groups here and there in the flavonoid, and this allows them to use soil conditions to control which microbes they talk to," said Rice biogeochemist Caroline Masiello, a co-author of the study.The Rice team, in collaboration with researchers at Cornell University, specifically analyzed how flavonoids mediate interactions between plants and microbes depending on the presence of abiotic (nonliving) carbon. Their experiments revealed, to their surprise, that an excess of dissolved -- rather than solid -- carbon in soil effectively quenches flavonoid signals.Understanding how carbon in soil affects these signals may provide a way to engineer beneficial interactions between plants and microbes and to design effective soil amendments (additives that balance deficiencies in soil), according to the researchers. Plants use flavonoids as a defense mechanism against root pathogens and could manipulate the organic carbon they produce to interfere with signaling between microbes and other plants that compete for the same nutrients.Overall, they showed that higher organic carbon levels in soil repressed flavonoid signals by up to 98%. In one set of experiments, interrupting the signals between legume plants and microbes sharply cut the formation of nitrogen nodules.Rice graduate student Ilenne Del Valle began the study when she became interested in the subtle differences between the thousands of flavonoids and how they influence connections between plants and microbes in soil."We had studied how different soil amendments change how microbes communicate with one another," said Del Valle, co-lead author of the paper with former Cornell postdoctoral associate Tara Webster. "The next question was whether this was happening when the microbes communicate with plants."We knew that plants modulate symbiosis with microbes through flavonoid molecules," she said. "So we wanted to learn how flavonoids interact with soil amendments used for different purposes in agriculture."Because she counts two Rice professors -- Masiello and synthetic biologist Joff Silberg -- as her advisers, she had access to tools from both disciplines to discover the mechanisms behind those subtleties."We came into this thinking there was going to be a big effect from biochar," Silberg said. "Biochar is charcoal made for agricultural amendment, and it is well-known to affect microbe-microbe signals. It has a lot of surface area, and flavonoids look sticky, too. People thought they would stick to the biochar."They didn't. Instead, we found that dissolved carbon moving through water in the soil was affecting signals," he said. "It was very different from all of our expectations."The Rice and Cornell team set up experiments with soils from meadows, farms and forests and then mixed in three slightly different flavonoids: naringenin, quercetin and luteolin.They found the most dramatic effects when dissolved carbons derived from plant matter or compost were present. Plants employ naringenin, a variant of the flavonoid that gives grapefruit its bitter taste, and luteolin, expressed by leaves and many vegetables, to call for microbial nitrogen fixation. These were most curtailed in their ability to find microbes. Quercetin, also found in foods like kale and red onions and used for defense against pests, did not suffer the same fate.Masiello noted there's a cost for plants to connect with microbes in the soil."These relationships with symbionts are metabolically costly," she said. "Plants have to pay the microbes in photosynthesized sugar, and in exchange the microbes mine the soil for nutrients. Microbial symbionts can be really expensive subcontractors, sometimes taking a significant fraction of a plant's photosynthate."What Ilenne and Tara have shown is one mechanism through which plants can control whether they invest in expensive symbionts," she said. "Among a wide class of signaling compounds used by plants for many purposes, one specific signal related to nutrients is shut off by high soil organic matter, which is a slow-release source of nutrients. The plant signal that says 'come live with us' doesn't get through."This is good for plants because it means they don't waste photosynthate supporting microbial help they don't need. Ilenne and Tara have also shown that signals used for other purposes are slightly chemically modified so their transmission is not affected at the same rate."The researchers checked flavonoid concentrations in soil with standard chromatography as well as unique fluorescent and gas biosensors, genetically modified microbes introduced in 2016 with the support of a Keck Foundation grant, which also backed the current project. The microbes release a gas when they sense a particular microbial interaction in opaque materials like soil."The gas sensor ended up being very useful in experiments that looked like tea, where we couldn't image fluorescent signals," Silberg said.
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Agriculture & Food
| 2,020 |
January 29, 2020
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https://www.sciencedaily.com/releases/2020/01/200129091449.htm
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Traditional Chinese medicinal plant yields new insecticide compounds
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For hundreds of years, practitioners of traditional Chinese medicine have used an herb called
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Endophytes are microorganisms that live inside plant cells but do not cause apparent disease. Instead, some endophytes help plants survive by enhancing growth, nutrient acquisition, or resistance to drought or pests. Therefore, scientists are investigating endophytes as potential sources of new medicines and agrichemicals. Xiachang Wang, Lihong Hu and colleagues wanted to screen endophytes from To isolate endophytes, the researchers spread fresh, cut-up pieces of
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Agriculture & Food
| 2,020 |
January 29, 2020
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https://www.sciencedaily.com/releases/2020/01/200129091438.htm
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Pollination is better in cities than in the countryside
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Flowering plants are better pollinated in urban than in rural areas. This has now been demonstrated experimentally by a team of scientists led by the German Centre for Integrative Biodiversity Research (iDiv), the Martin Luther University Halle-Wittenberg (MLU) and the Helmholtz Centre for Environmental Research (UFZ). Although the scientists found a greater diversity of flying insects in the countryside, more bees in cities resulted in more pollinated flowers of test plants. By far the most industrious pollinators were bumble bees, most likely benefitting from the abundant habitats available in the city. To promote pollination, the researchers recommend to take into greater account the needs of bees when landscape planning -- both in cities and in the countryside. Their results have been published in the journal
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Cities all over the world are expanding. A number of studies have already shown that the conversion of natural areas into built land affects insects and, while the diversity and abundance of insects often decreases, some insect species or species groups may benefit. However, little is known about the effects of urbanisation on the ecosystem services insects provide, such as plant pollination.A team of scientists led by the German Centre for Integrative Biodiversity Research (iDiv), the Martin Luther University Halle-Wittenberg (MLU) and the Helmholtz Centre for Environmental Research (UFZ) have now investigated the effect of the urban environment on insect pollinators and pollination. For this purpose, flower-rich, inner city locations such as parks and botanical gardens were compared with similarly flower-rich sites in rural areas surrounding nine large German cities; Berlin, Braunschweig, Chemnitz, Dresden, Göttingen, Halle, Jena, Leipzig and Potsdam. The scientists sampled flying insects using pan-traps and potted red clover plants as reference for pollination in all locations. Furthermore, they also recorded all insect visits to red clover flowers 20 times a day for 15 minutes. The seeds produced were also counted, thus determining the rate of pollination success.The most successfully pollinated plants were in the cities; here the flowers were visited more often than in the rural areas. Although the researchers found a greater biodiversity and biomass of flying insects in the rural areas -- especially flies and butterflies -- these did little to pollinate the red clover. This job was done predominantly by bees, which showed higher species richness and flower visitation rates in cities. Indeed, three out of four of the recorded flower-visitors were bumble bees. At a frequency of 8.7 percent, the honey bee was the second most important pollinator.The researchers believe the great diversity and numbers of bees in cities is due to the availability of suitable habitats available for wild bees and bumblebees. Good nesting opportunities are found in exposed soils, dead wood and wall cavities, and the large variety of flowering plants in parks and gardens ensures a reliable food supply. Also, bees probably cope better with the challenge of highly dynamic city life than other groups of insects. "Urban people are constantly changing their environment. Finding your way around is a challenge that bees are particularly well-equipped to deal with due to their highly developed orientation and learning skills," says the head of the study, Prof Robert Paxton, scientist from Martin Luther University Halle-Wittenberg (MLU) and the German Centre for Integrative Biodiversity Research (iDiv). "Flies and butterflies obviously find this more difficult."Invariably, almost all the insect species assessed benefit from diverse habitat structures which reliably provide food, nesting sites and orientation. In agricultural land these are flower strips, grassland, forest and hedges, and in inner city locations, gardens, wastelands and parks. These are often missing in an extensively cleared agricultural landscape. "I was really shocked at how consistently poor the pollination performance in agricultural land was," says Paxton. "Other studies have shown that wild bees and bumble bees are particularly susceptible to pesticides. This could also help explain why their diversity is greater in the city, where pesticides play a lesser role."The figures show just how important pollination is, both for ecosystems and humankind. An estimated 90 percent of all flowering plant species rely on pollination by animals; insect pollinators are essential for maintaining plant diversity. But the food we eat also depends on pollination; the value of pollinators' services to global agriculture in 2015 was calculated at between $235 and $557 billion.Flowering plants and their pollinators also play an important role in cities. "What would our urban green spaces be without flowers?" says lead author Dr Panagiotis Theodorou, scientist from the German Centre for Integrative Biodiversity Research (iDiv), Martin Luther University Halle-Wittenberg (MLU) and the Helmholtz Centre for Environmental Research (UFZ). "The number of urban vegetable gardens and orchards is also growing, but without pollinators, no fruit will ripen there."In the medium term, however, cities could also help to maintain rural pollination. "If agricultural land degrades further, cities could serve as a source of pollinators for the farmland surrounding them," says Theodorou. The researchers therefore recommend that cities should be made more attractive to pollinators, and that the needs of the hardworking bumble bee should be especially taken into account when planning green spaces. But of course, more flower-rich areas and suitable nesting sites also need to be created in the countryside and linked to city habitats so as to boost pollination in commercial orchards.
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Agriculture & Food
| 2,020 |
January 27, 2020
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https://www.sciencedaily.com/releases/2020/01/200127134756.htm
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19th-century bee cells in a Panamanian cathedral shed light on human impact on ecosystems
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Despite being "neotropical-forest-loving creatures," some orchid bees are known to tolerate habitats disturbed by human activity. However, little did the research team of Paola Galgani-Barraza (Smithsonian Tropical Research Institute) expect to find as many as 120 clusters of nearly two-centuries-old orchid bee nests built on the altarpiece of the Basilica Cathedral in Casco Viejo (Panamá).
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This happened after restoration work, completed in 2018 in preparation for the consecration of a new altar by Pope Francis, revealed the nests. Interestingly, many cells were covered with gold leaf and other golden material applied during an earlier restoration following an 1870 fire, thus aiding the reliable determination of the age of the clusters. The cells were dated to the years prior to 1871-1876.The bee species, that had once constructed the nests, was identified as the extremely secretive Eufriesea surinamensis. Females are known to build their nests distant from each other, making them very difficult to locate in the field. As a result, there is not much known about them: neither about the floral resources they collect for food, nor about the materials they use to build their nests, nor about the plants they pollinate.However, by analysing the preserved pollen for the first time for this species, the researchers successfully detected the presence of 48 plant species, representing 43 genera and 23 families. Hence, they concluded that late-nineteenth century Panama City was surrounded by a patchwork of tropical forests, sufficient to sustain nesting populations of what today is a forest-dwelling species of bee.Not only did the scientists unveil important knowledge about the biology of orchid bees and the local floral diversity in the 19th century, but they also began to uncover key information about the functions of natural ecosystems and their component species, where bees play a crucial role as primary pollinators. Thus, the researchers hope to reveal how these environments are being modified by collective human behaviour, which is especially crucial with the rapidly changing environment that we witness today.
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Agriculture & Food
| 2,020 |
January 24, 2020
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https://www.sciencedaily.com/releases/2020/01/200124124518.htm
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Dance of the honey bee reveals fondness for strawberries
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Bees are pollinators of many wild and crop plants, but in many places their diversity and density is declining. A research team from the Universities of Göttingen, Sussex and Würzburg has now investigated the foraging behaviour of bees in agricultural landscapes. To do this, the scientists analysed the bees' dances, which are called the "waggle dance." They found out that honey bees prefer strawberry fields, even if they flowered directly next to the oilseed rape fields. Only when oilseed rape was in full bloom were fewer honey bees observed in the strawberry field. Wild bees, on the other hand, consistently chose the strawberry field. The results have been published in the journal
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A team from the Functional Agrobiodiversity and Agroecology groups at the University of Göttingen established small honey bee colonies next to eleven strawberry fields in the region of Göttingen and Kassel. The scientists then used video recordings and decoded the waggle dances. Honey bees dance to communicate the direction and distance of attractive food sources that they have visited. In combination with satellite maps of the landscape, the land use type that they preferred could be determined. The team also studied which plants the bees used as pollen resources and calculated the density of honey bees and wild bees in the study fields.Their results: honey bees prefer the strawberry fields, even when oilseed rape is flowering abundantly in the area. However, honey bees from the surrounding landscapes are less common in the strawberry fields when oilseed rape is in full bloom. "In contrast, solitary wild bees, like mining bees, are constantly present in the strawberry field," says first author Svenja Bänsch, post-doctoral researcher in the Functional Agrobiodiversity group at the University of Göttingen. "Wild bees are therefore of great importance for the pollination of crops," emphasizes Professor Teja Tscharntke, Head of the Agroecology group."With this study, we were able to show that small honey bee colonies in particular can be suitable for the pollination of strawberries in the open field. However, our results also show that wild bees in the landscape should be supported by appropriate management measures," concludes Head of Functional
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Agriculture & Food
| 2,020 |
January 23, 2020
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https://www.sciencedaily.com/releases/2020/01/200123134053.htm
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New experimental vaccine for African swine fever virus shows promise
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Government and academic investigators have developed a vaccine against African swine fever that appears to be far more effective than previously developed vaccines. The research appears this week in the
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Currently, there is no commercially available vaccine against African swine fever, which has been devastating the swine industry in Eastern Europe and Southeast Asia. African swine fever virus (ASFV) is highly contagious and often lethal to domestic and wild pigs. Outbreaks have been quelled -- more or less -- "by animal quarantine and slaughter," according to the report. (Humans are not susceptible to ASFV.)In the study, both low and high doses of the vaccine were 100% effective against the virus when the pigs were challenged 28 days post-inoculation.The research was motivated by the 2007 outbreak of African swine fever in the Republic of Georgia, said principal investigator Douglas P. Gladue, PhD, Senior Scientist, Plum Island Animal Disease Center, Agricultural Research Service, US Department of Agriculture. "This was the first outbreak in recent history outside of Africa and Sardinia -- where swine fever is endemic -- and this particular strain has been highly lethal and highly contagious, spreading quickly to neighboring countries." This is also a new strain of the virus, now known as ASFV-G (the G stands for Georgia).The 2007 outbreak was also the genesis of the African swine fever that has been spreading through Eastern Europe and east Asia, said Manuel V. Borca, PhD, also a Senior Scientist at the Plum Island Animal Disease Center.There is limited cross-protection between strains of African swine fever, likely because the antigens and degree of virulence differ among them, and none of the historical experimental vaccines have been shown to be effective against ASFV-G, said Dr. Gladue.So the investigators at Plum Island Animal Disease Center set out to develop a vaccine. Part of the process of developing whole virus vaccines involves deleting virulence genes from the virus. But when the researchers deleted genes similar to those that had been deleted in older ASFV strains to attenuate them, "it became clear that ASFV-G was much more virulent" than the other, historical isolates, because it retained a higher level of virulence, said Dr. Gladue. The investigators then realized they needed a different genetic target in order to attenuate ASFV-G.They used a predictive methodology called a computational pipeline to predict the roles of proteins on the virus. The computational pipeline predicted that a protein called I177l could interfere with the immune system of the pig. When they deleted this gene, ASFV-G was completely attenuated.More work needs to be done to meet regulatory requirements for commercialization, said Dr. Gladue. But "This new experimental ASFV vaccine shows promise, and offers complete protection against the current strain currently producing outbreaks throughout Eastern Europe and Asia."
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Agriculture & Food
| 2,020 |
January 23, 2020
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https://www.sciencedaily.com/releases/2020/01/200123095853.htm
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US households waste nearly a third of the food they acquire
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American households waste, on average, almost a third of the food they acquire, according to economists, who say this wasted food has an estimated aggregate value of $240 billion annually. Divided among the nearly 128.6 million U.S. households, this waste could be costing the average household about $1,866 per year.
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This inefficiency in the food economy has implications for health, food security, food marketing and climate change, noted Edward Jaenicke, professor of agricultural economics, College of Agricultural Sciences, Penn State."Our findings are consistent with previous studies, which have shown that 30% to 40% of the total food supply in the United States goes uneaten -- and that means that resources used to produce the uneaten food, including land, energy, water and labor, are wasted as well," Jaenicke said. "But this study is the first to identify and analyze the level of food waste for individual households, which has been nearly impossible to estimate because comprehensive, current data on uneaten food at the household level do not exist."The researchers overcame this limitation by borrowing methodology from the fields of production economics -- which models the production function of transforming inputs into outputs -- and nutritional science, by which a person's height, weight, gender and age can be used to calculate metabolic energy requirements to maintain body weight.In this novel approach, Jaenicke and Yang Yu, doctoral candidate in agricultural, environmental and regional economics, analyzed data primarily from 4,000 households that participated in the U.S. Department of Agriculture's National Household Food Acquisition and Purchase Survey, known as FoodAPS. Food-acquisition data from this survey were treated as the "input."FoodAPS also collected biological measures of participants, enabling the researchers to apply formulas from nutritional science to determine basal metabolic rates and calculate the energy required for household members to maintain body weight, which is the "output." The difference between the amount of food acquired and the amount needed to maintain body weight represents the production inefficiency in the model, which translates to uneaten, and therefore wasted, food."Based on our estimation, the average American household wastes 31.9% of the food it acquires," Jaenicke said. "More than two-thirds of households in our study have food-waste estimates of between 20% and 50%. However, even the least wasteful household wastes 8.7% of the food it acquires."In addition, demographic data collected as part of the survey were used to analyze the differences in food waste among households with a variety of characteristics.For example, households with higher income generate more waste, and those with healthier diets that include more perishable fruits and vegetables also waste more food, according to the researchers, who reported their findings in the "It's possible that programs encouraging healthy diets may unintentionally lead to more waste," Jaenicke said. "That may be something to think about from a policy perspective -- how can we fine-tune these programs to reduce potential waste."Household types associated with less food waste include those with greater food insecurity -- especially those that participate in the federal SNAP food assistance program, previously known as "food stamps" -- as well as those households with a larger number of members."People in larger households have more meal-management options," Jaenicke explained. "More people means leftover food is more likely to be eaten."In addition, some grocery items are sold in sizes that may influence waste, he said."A household of two may not eat an entire head of cauliflower, so some could be wasted, whereas a larger household is more likely to eat all of it, perhaps at a single meal."Among other households with lower levels of waste are those who use a shopping list when visiting the supermarket and those who must travel farther to reach their primary grocery store."This suggests that planning and food management are factors that influence the amount of wasted food," Jaenicke said.Beyond the economic and nutritional implications, reducing food waste could be a factor in minimizing the effects of climate change. Previous studies have shown that throughout its life cycle, discarded food is a major source of greenhouse gas emissions, the researchers pointed out."According to the U.N. Food and Agriculture Organization, food waste is responsible for about 3.3 gigatons of greenhouse gas annually, which would be, if regarded as a country, the third-largest emitter of carbon after the U.S. and China," Jaenicke said.The researchers suggested that this study can help fill the need for comprehensive food-waste estimates at the household level that can be generalized to a wide range of household groups."While the precise measurement of food waste is important, it may be equally important to investigate further how household-specific factors influence how much food is wasted," said Jaenicke. "We hope our methodology provides a new lens through which to analyze individual household food waste."The U.S. Department of Agriculture's National Institute of Food and Agriculture supported this work through its Agriculture and Food Research Initiative.
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Agriculture & Food
| 2,020 |
January 22, 2020
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https://www.sciencedaily.com/releases/2020/01/200122175710.htm
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Climate-friendly food choices protect the planet, promote health, reduce health costs
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Increased uptake of plant-based diets in New Zealand could substantially reduce greenhouse gas emissions while greatly improving population health and saving the healthcare system billions of dollars in the coming decades, according to a new University of Otago study.
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Lead researcher and Otago medical student Jono Drew explains the global food system is driving both the climate crisis and the growing burden of common chronic diseases like cardiovascular disease, diabetes, and cancer."International research has highlighted the climate and health co-benefits that arise from consuming a diet that is rich in plant foods like vegetables, fruits, whole grains and legumes. We wanted to understand if this holds true here in New Zealand, and to tease out which eating patterns could offer the greatest co-benefits in this context."The research team developed a New Zealand-specific food emissions database that, in estimating greenhouse gas emissions arising from foods commonly consumed in New Zealand, considers important parts of the 'lifecycle' of each food, including farming and processing, transportation, packaging, warehouse and distribution, refrigeration needs, and supermarket overheads. Using their database, the team was then able to model climate, health, and health system cost impacts stemming from a range of dietary scenarios.Senior author Dr Alex Macmillan, Senior Lecturer in Environmental Health, says results from the study show that greenhouse gas emissions vary considerably between different foods in New Zealand. As a general rule, the climate impact of animal-based foods, particularly red and processed meats, tends to be substantially higher than that of whole plant-based foods, including vegetables, fruits, legumes, and whole grains."Fortunately, foods that are health-promoting tend also to be those that are climate friendly. Conversely, certain foods that carry known health risks are particularly climate-polluting. Red and processed meat intake, for instance, is associated with an increased risk of cardiovascular disease, type-2 diabetes and certain cancers," Dr Macmillan says.The research ultimately shows that a population-level dietary shift could, depending on the extent of changes made, offer diet-related emissions savings of between 4 to 42 per cent annually, along with health gains of between 1.0 to 1.5 million quality-adjusted life-years (a single quality-adjusted life-year is equal to one year of optimal health) and cost savings to the health system of NZD $14 to $20 billion over the lifetime of the current New Zealand population.Mr Drew says the analysis reveals emissions savings equivalent to a 59 per cent reduction in New Zealand's annual light passenger vehicle emissions could be possible if New Zealand adults consumed an exclusively plant-based diet and avoided wasting food unnecessarily."All of our scenarios were designed to meet New Zealand's dietary guidelines. We began with a baseline scenario where we looked at minimal dietary changes required, relative to what New Zealanders are consuming now, to meet the guidelines. These changes included increased intake of vegetables, fruits, whole grains and milk, along with decreased intake of highly processed foods. From there, we tailored our dietary scenarios to be progressively more plant-based- that is, substituting animal-based foods with plant-based alternatives."We thought it was important to show what was possible if people were willing to make changes to their eating pattern, and what would be possible if our entire population made a significant shift in that same direction," Mr Drew says."As our modelled dietary scenarios became increasingly plant-based and therefore more climate-friendly, we found that associated population-level health gains and healthcare cost savings tended also to increase. A scenario that replaced all meat, seafood, eggs, and dairy products with plant-based alternatives, and that also required people to cut out all unnecessary household food waste, was found to offer the greatest benefit across all three of these parameters," he says.Mr Drew says this is exciting because we can now better understand what it means to promote a climate-friendly eating pattern in the New Zealand context. "Essentially, the message is highly comparable to that being delivered in other countries already, and we should be rapidly looking for ways to effectively support our population in making eating pattern changes."The researchers argue that these findings should prompt national policy action, including revising the New Zealand dietary guidelines to include messaging on climate-friendly food choices. They also advocate for the implementation of other policy tools, such as pricing strategies, labeling schemes, and food procurement guidelines for public institutions."Well-designed public policy is needed worldwide to support the creation of a global food system that no longer exacerbates the climate crisis, nor the burden of non-communicable disease," Mr Drew says.
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Agriculture & Food
| 2,020 |
January 22, 2020
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https://www.sciencedaily.com/releases/2020/01/200122150024.htm
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Domesticated wheat has complex parentage
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Certain types of domesticated wheat have complicated origins, with genetic contributions from wild and cultivated wheat populations on opposite sides of the Fertile Crescent. Terence Brown and colleagues at the University of Manchester report these findings in a new paper published January 22, 2020 in the open-access journal
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A wild form of wheat called emmer wheat was one of the first plant species that humans domesticated. Emmer is not grown widely today, but gave rise to the durum wheat used for pasta and hybridized with another grass to make bread wheat, so its domestication was an important step in the transition from hunting and gathering to agriculture. While the archaeological record suggests that cultivation began in the southern Levant region bordering the eastern edge of the Mediterranean Sea around 9,500 years ago, genetic studies point to an origin in the northern region of the Fertile Crescent, in what is now Turkey. To clarify emmer's origins, researchers screened 189 types of wild and domesticated wheats and used the more that 1 million genetic variations that they identified to piece together the genetic relationships between different kinds of wheat.Based on the analysis, the researchers propose that an emmer crop, which humans cultivated but had not yet domesticated, spread from the southern Levant to southeast Turkey, where it mixed with a wild emmer population and ultimately yielded the first domesticated variety. The results of this hybridization can be detected in wild emmer plants in Turkey today.The complex evolutionary relationships between wild emmer and cultivated wheat varieties uncovered by the analysis are similar to the interbreeding that occurred between wild and cultivated populations of other grain crops, such as barley and rice.The authors add: "We used next-generation DNA sequencing technologies to detect hundreds of thousands of variants in the genomes of wild and cultivated emmer wheat, giving us an unprecedented insight into the complexity of its domestication process. The patterns we observed do not fit well with a simplistic model of fast and localized domestication event but suggest instead a long process of cultivation of wild wheat by hunter-gatherer communities connected throughout the Fertile Crescent, prior to the emergence of a fully domesticated wheat form."
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Agriculture & Food
| 2,020 |
January 22, 2020
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https://www.sciencedaily.com/releases/2020/01/200122150022.htm
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Even after death, animals are important in ecosystems
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Animal carcasses play an important role in biodiversity and the functioning of ecosystems, also over prolonged periods. Scientists from the German Centre for Integrative Biodiversity Research (iDiv) and the University of Groningen have published these findings in the journal
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In the Dutch nature reserve Oostvaardersplassen, one of the largest wetland areas in Central Europe, the scientists investigated how red deer carcasses impact local biodiversity. To this purpose, they first recorded the presence of insect species on surfaces both with and without carcasses, and then plant growth in the immediate vicinity of a carcass. They found that the carcasses not only directly benefit many carrion-eating insects like flies or carrion beetles, they also have a positive long-term effect on plant growth.Plants such as the Welted Thistle (The results shed new light on the role of animal carcasses in the ecosystem. "It is now largely accepted that dead wood remains in our forests -- which benefits many species," says Prof Chris Smit from the University of Groningen. "However, the sight of dead animals in nature is often still a social taboo, and this is a shame given their important value for ecosystems and biodiversity." Apart from this, EU laws make it difficult to leave the carcasses of large animals in nature reserves. The authors recommend relaxing these regulations for nature reserves.
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Agriculture & Food
| 2,020 |
January 22, 2020
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https://www.sciencedaily.com/releases/2020/01/200122080513.htm
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Vomiting bumblebees show that sweeter is not necessarily better
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Animal pollinators support the production of three-quarters of the world's food crops, and many flowers produce nectar to reward the pollinators. A new study using bumblebees has found that the sweetest nectar is not necessarily the best: too much sugar slows down the bees. The results will inform breeding efforts to make crops more attractive to pollinators, boosting yields to feed our growing global population.
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Bumblebees drink nectar from flowers, then offload it in their nest -- by vomiting -- for use by other bees in the colony. The sugar within nectar makes it appealing, and the more sugar within the nectar, the more energy it contains. But nectar also gets more thick and sticky as the sugar content rises, and this makes it more difficult for bees to drink and regurgitate -- requiring more time and energy.Published today in the "Bumblebees must strike a balance between choosing a nectar that is energy-rich, but isn't too time-consuming to drink and offload. Nectar sugar concentration affects the speed of the bees' foraging trips, so it influences their foraging decisions," said Dr Jonathan Pattrick, first author of this study, formerly a PhD student based jointly in the University of Cambridge's departments of Plant Sciences and Zoology and now a post-doctoral researcher in the University of Oxford's Department of Zoology.While it has long been known that nectar with a higher sugar concentration takes bees longer to drink, its effect on nectar regurgitation has not previously received much attention. This new information will help scientists make better predictions about which types of nectar bumblebees and other pollinators should like best, and consequently the kinds of flowers and plants they are most likely to visit. This will inform crop breeders in producing the most appealing flowers for better crop pollination and higher yields.To conduct the research, bees were allowed to forage on sugar solutions of three different concentrations in the Department of Plant Science's Bee Lab. While doing this, the bees were also timed and weighed. When the bees returned to their 'nest', the researchers watched them through a Perspex lid, timing how long it took for the bees to vomit up the nectar they had collected."For low strength nectar, bees had a quick vomit that only lasted a few seconds, then were back out and foraging again," said Pattrick, "but for really thick nectar they took ages to vomit, sometimes straining for nearly a minute."For any given nectar concentration, bees regurgitate the nectar quicker than they initially drink it. But as nectar sugar concentration -- and therefore stickiness -- goes up, the rate of regurgitation decreases faster than the rate of drinking. "It's hard to drink a thick, sticky liquid, but imagine trying to spit it out again through a straw -- that would be even harder," said Pattrick. "At a certain sugar concentration, the energy gain versus energy loss is optimised for nectar feeders."The perfect nectar sugar concentration for the highest energy intake depends on the species drinking it, because different species feed in different ways. Bumblebees and honeybees feed by dipping their tongue repeatedly into the nectar, but regurgitate by forcing the nectar back up through a tube -- just like when humans are sick. Other species such as Orchid Bees suck nectar up instead of lapping it, so struggle even more when nectar is highly concentrated. This influences nectar preference and the plants visited by different species.Current crop breeding is focused on enhancing traits like yield and disease resistance, rather than considering pollinator preference. The new results improve predictions of the perfect nectar concentration for making the most efficient use of pollinating bumblebees.Nectar is produced by flowers to attract pollinators, and a source of food for many species of insect, bird and mammal. The levels of the sugars sucrose, glucose and fructose within the nectar vary depending on the plant producing it."Studies have shown that numbers of some pollinators are going down, but there are more and more people in the world to feed. We need to make better use of the pollinators we have," said Professor Beverley Glover in Cambridge's Department of Plant Sciences and Director of Cambridge University Botanic Garden, who led the study. "This research will help us understand the types of flowers and plants the bees are most likely to visit, which will inform crop breeding to make the best use of the available pollinators."
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Agriculture & Food
| 2,020 |
January 21, 2020
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https://www.sciencedaily.com/releases/2020/01/200121124022.htm
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Feeding the world without wrecking the planet is possible
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"When looking at the status of planet Earth and the influence of current global agriculture practices upon it, there's a lot of reason to worry, but also reason for hope -- if we see decisive actions very soon," Dieter Gerten says, lead author from PIK and professor at Humboldt University of Berlin. "Currently, almost half of global food production relies on crossing Earth's environmental boundaries. We appropriate too much land for crops and livestock, fertilize too heavily and irrigate too extensively. To solve this issue in the face of a still growing world population, we collectively need to rethink how to produce food. Excitingly, our research shows that such transformations will make it possible to provide enough food for up to 10 billion people."
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The researchers ask the question how many people could be fed while keeping a strict standard of environmental sustainability worldwide. These environmental capacities are defined in terms of a set of planetary boundaries -- scientifically defined targets of maximum allowed human interference with processes that regulate the state of the planet. The present study accounts for four of nine boundaries most relevant for agriculture: Biosphere integrity (keeping biodiversity and ecosystems intact), land-system change, freshwater use, and nitrogen flows. Based on a sophisticated simulation model, the impacts of food on these boundaries are scrutinised at a level of spatial and process detail never accomplished before, and moreover aggregated to the entire planet. This analysis demonstrates where and how many boundaries are being violated by current food production and in which ways this development could be reverted through adopting more sustainable forms of agriculture.The encouraging result is that, in theory, 10 billion people can be fed without compromising the Earth system. This leads to very interesting conclusions, as Johan Rockström, director of PIK points out: "We find that currently, agriculture in many regions is using too much water, land, or fertilizer. Production in these regions thus needs to be brought into line with environmental sustainability. Yet, there are huge opportunities to sustainably increase agricultural production in these and other regions. This goes for large parts of Sub-Saharan Africa, for example, where more efficient water and nutrient management could strongly improve yields."As a positive side effect, sustainable agriculture can increase overall climate resilience while also limiting global warming. In other places, however, farming is so far off local and Earth's boundaries that even more sustainable systems could not completely balance the pressure on the environment, such as in parts of the Middle East, Indonesia, and to some extent in Central Europe. Even after recalibrating agricultural production, international trade will remain a key element of a sustainably fed world.Importantly, there is the consumers' end, too. Large-scale dietary shifts seem to be inevitable for turning the tide to a sustainable food system. For example, regarding China's currently rising meat consumption, parts of animal proteins would need to be substituted by more legumes and other vegetables. "Changes like this might seem hard to chew at first. But in the long run, dietary changes towards a more sustainable mix on your plate will not only benefit the planet, but also people's health," adds Vera Heck from PIK. Another crucial factor is reducing food loss. In line with scenarios adopted in the present study, the most recent IPCC Special Report on land use found that currently, up to 30 percent of all food produced is lost to waste. "This situation clearly calls for resolute policy measures to set incentives right on both the producers' and consumers' ends," Heck further lays out.Perhaps the most sensitive and challenging implication of the study relates to land. "Anything involving land tends to be complex and contested in practice because people's livelihoods and outlook depend on it. Transitioning to more sustainable land use and management is therefore a demanding challenge to policy-making. Key to success is that the regions affected need to see clear benefits for their development. Then there is a real chance that support for new directions will grow fast enough for stabilising the Earth system," says Wolfgang Lucht, co-chair for Earth System Analysis at PIK and co-author of the study.
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Agriculture & Food
| 2,020 |
January 21, 2020
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https://www.sciencedaily.com/releases/2020/01/200121112948.htm
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Banning food waste: Lessons for rural America
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While Vermonters support banning food waste from landfills -- and a whopping 72 percent already compost or feed food scraps to their pets or livestock -- few say they are willing to pay for curbside composting pick-up, new University of Vermont research shows.
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The study comes as Vermont prepares to implement a mandatory law that makes it illegal to throw food items in the trash beginning July 1, 2020. Several large cities including San Francisco and Seattle have implemented similar policies, but Vermont is the first state to ban household food waste from landfills. The policy is the last phase of a universal state recycling law passed in 2012 that bans all food waste, "blue bin" recyclables and yard debris from landfills statewide by 2020."Reducing household food waste is a powerful way individuals can help reduce the impacts of climate change and save money," said Meredith Niles, UVM Food Systems and Nutrition and Food Sciences assistant professor and lead author of the study. "Vermont has made a significant commitment to this effort and it's exciting to see the majority of Vermonters are already composting to do their part."Previous research by Niles and other UVM colleagues showed Americans waste nearly a pound of food daily, roughly one third of a person's recommended daily calories. When disposed of in a landfill, food waste rots and produces methane, a greenhouse gas 25 times more powerful than carbon dioxide over a 100-year period, according to the U.S. Environmental Protection Agency. Conversely, composting can aid in carbon sequestration and creates a natural fertilizer for farms and gardens.While several states and municipalities are exploring food waste strategies, few studies have examined food waste perceptions and behaviors in rural communities."The trend in big cities has been to offer curbside compost pickup programs, especially in densely populated areas, but there isn't a one size fits all for how we manage food waste," said Niles. "Our study suggests that, especially in more rural areas, people may already be managing their food waste in a way that leaves it out of the landfills."Niles surveyed nearly 600 households through the 2018 state Vermonter Poll, conducted annually by UVM's Center for Rural Studies. The study showed support for the new food waste ban, but only a minority of residents indicated they would be willing to pay for a future curbside compost pickup program. People in urban counties were significantly more likely to want curbside compost pickup compared to those managing their food waste through backyard composting or by feeding to pets or livestock."In a rural state like Vermont, households are generally further apart, which can increase food waste transport costs and have a negative environmental impact, especially if participation in a curbside compost program is low," said Niles, who is also a fellow at UVM's Gund Institute for Environment. "Instead, focusing curbside programs in densely populated areas may be more cost and environmentally effective and also garner greater household participation."Research has shown the rates of home composting in Vermont are much higher than in other regions. One third of Vermonters indicated they are exclusively composting or feeding food scraps to pets or livestock, with no food scraps ending up in the trash. This research suggests that investing in education, outreach and infrastructure to help households manage their own food waste could have significant environmental and economic impacts in other rural regions seeking food waste management solutions.
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Agriculture & Food
| 2,020 |
January 21, 2020
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https://www.sciencedaily.com/releases/2020/01/200121112946.htm
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Predators are most likely to be lost when habitats are converted for human use
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A first of its kind, global study on the impacts of human land-use on different groups of animals has found that predators, especially small invertebrates like spiders and ladybirds, are the most likely to be lost when natural habitats are converted to agricultural land or towns and cities. The findings are published in the British Ecological Society journal
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Small ectotherms (cold blooded animals such as invertebrates, reptiles and amphibians), large endotherms (mammals and birds) and fungivores (animals that eat fungi) were also disproportionally affected, with reductions in abundance of 25-50% compared to natural habitats.The researchers analysed over one million records of animal abundance at sites ranging from primary forest to intensively managed farmland and cities. The data represented over 25,000 species across 80 countries. Species were grouped by size, whether they were warm or cold blooded and by what they eat. Species ranged from the oribatid mite weighing only 2x10-6g, to an African elephant weighing 3,825kg.Dr. Tim Newbold at UCL (University College London) and lead author of the research said: "Normally when we think of predators, we think of big animals like lions or tigers. These large predators did not decline as much as we expected with habitat loss, which we think may be because they have already declined because of human actions in the past (such as hunting). We find small predators -- such as spiders and ladybirds -- to show the biggest declines."The results indicate that the world's ecosystems are being restructured with disproportionate losses at the highest trophic levels (top of the food chain). Knowing how different animal groups are impacted by changing land-use could help us better understand how these ecosystems function and the consequences of biodiversity change."We know that different types of animals play important roles within the environment -- for example, predators control populations of other animals. If some types of animals decline a lot when we lose natural habitats, then they will no longer fulfil these important roles." said Dr. Tim Newbold.The conversion of land to human use is associated with the removal of large amounts of natural plant biomass, usually to give space for livestock and crops. The limiting of the quantity and diversity of resources available at this level potentially explains the disproportionate reductions in predators seen in this study. As you go up the trophic levels (food chain), resource limitations are compounded through a process known as bottom-up resource limitation.The study is part of the PREDICTS project which explores how biodiversity responds to human pressures. The researchers analysed 1,184,543 records of animal abundance in the PREDICTS database, gathered from 460 published scientific studies. This database included all major terrestrial vertebrate taxa and many invertebrate taxa (25,166 species, 1.8% of described animals).Species were sorted into functional groups defined by their size, trophic level (what they consumed) and thermal regulation strategy (warm or cold blooded). The type of land-use at each of the 13,676 sample sites was classified from the description of the habitat in the source publication. The six broad categories were primary vegetation, secondary vegetation, plantation forest, cropland, pasture and urban. Three levels of human use intensity were also recorded: minimal, light and intense.Dr. Tim Newbold explained that studies like this are limited by the available data: "As with all global studies, we are limited in the information that is available to us about where animals are found and what they eat. We were able to get information for more animals than ever before, but this was still only around 1 out of every 100 animals known to science."The researchers also observed biases in the spread of data across types of land-use, animal groups and parts of the world. "Natural habitats and agricultural areas have been studied more than towns and cities. We think this is because ecologists tend to find these environments more interesting than urban areas as there tend to be more animals in them." said Dr. Tim Newbold. The researchers also found that large parts of Asia were under sampled for several functional groups. Birds were also better represented among vertebrates and insects better represented among invertebrates.The researchers are now interested in exploring how groups of animals that play particularly important roles for agriculture, such as pollinating or controlling crop pests, are affected by habitat loss.
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Agriculture & Food
| 2,020 |
January 21, 2020
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https://www.sciencedaily.com/releases/2020/01/200121112917.htm
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Insecticides are becoming more toxic to honey bees
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During the past 20 years, insecticides applied to U.S. agricultural landscapes have become significantly more toxic -- over 120-fold in some midwestern states -- to honey bees when ingested, according to a team of researchers, who identified rising neonicotinoid seed treatments in corn and soy as the primary driver of this change. The study is the first to characterize the geographic patterns of insecticide toxicity to bees and reveal specific areas of the country where mitigation and conservation efforts could be focused.
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According to Christina Grozinger, Distinguished Professor of Entomology and director of the Center for Pollinator Research, Penn State, this toxicity has increased during the same period in which widespread decline in populations of pollinators and other insects have been documented."Insecticides are important for managing insects that damage crops, but they can also affect other insect species, such as bees and other pollinators, in the surrounding landscape," she said. "It is problematic that there is such a dramatic increase in the total insecticide toxicity at a time when there is also so much concern about declines in populations of pollinating insects, which also play a very critical role in agricultural production."The researchers, led by Maggie Douglas, assistant professor of environmental studies, Dickinson College, and former postdoctoral fellow, Penn State, integrated several public databases -- including insecticide use data from the U.S. Geological Survey, toxicity data from the Environmental Protection Agency, and crop acreage data from the U.S. Department of Agriculture -- to generate county-level annual estimates of honey bee "toxic load" for insecticides applied between 1997 and 2012. The team defined toxic load as the number of lethal doses to bees from all insecticides applied to cropland in each county.The researchers generated separate estimates for contact-based toxic loads, such as when a bee is sprayed directly, and oral-based toxic loads, such as when a bee ingests the pollen or nectar of a plant that has recently been treated. They generated a map of predicted insecticide toxic load at the county level. Their results appear today (Jan. 21) in The team found that the pounds of insecticides applied decreased in most counties from 1997 to 2012, while contact-based bee toxic load remained relatively steady. In contrast, oral-based bee toxic load increased by 9-fold, on average, across the U.S. This pattern varied by region, with the greatest increase -- 121-fold -- seen in the Heartland, which the U.S. Department of Agriculture defines as all of Iowa, Illinois and Indiana; most of Missouri; and part of Minnesota, Ohio, Kentucky, Nebraska and South Dakota. The Northern Great Plains had the second highest increase at 53-fold. This region includes all of North Dakota and part of South Dakota, Nebraska, Colorado, Wyoming, Montana and Minnesota."This dramatic increase in oral-based toxic load is connected to a shift toward widespread use of neonicotinoid insecticides, which are unusually toxic to bees when they are ingested," said Douglas.The most widely used family of insecticides in the world, neonicotinoids are commonly used as seed coatings in crops, such as corn and soybean. Some of the insecticide is taken up by the growing plants and distributed throughout their tissues, while the rest is lost to the environment."Several studies have shown that these seed treatments have negligible benefits for most crops in most regions," said Grozinger. "Unfortunately, growers often don't have the option to purchase seeds without these treatments; they don't have choices in how to manage their crops."The researchers suggest that the common method of evaluating insecticide use trends in terms of pounds of insecticides applied does not give an accurate picture of environmental impact."The indicator we use -- bee toxic load -- can be considered as an alternative indicator in cases where impacts to bees and other non-target insects is a concern," said Douglas. "This is particularly relevant given that many states have recently developed 'Pollinator Protection Plans' to monitor and address pollinator declines. Ultimately, our work helps to identify geographic areas where in-depth risk assessment and insecticide mitigation and conservation efforts could be focused.""It is important to note that the calculation of bee toxic load provides information about the total toxicity of insecticides applied to a landscape," said Grozinger. "It does not calculate how much of that insecticide actually comes in contact with bees, or how long the insecticide lasts before it is broken down. Future studies are needed to determine how toxic load associates with changes in populations of bees and other insects."This research is part of a larger project to investigate the various stressors impacting pollinator populations across the United States. One tool created within this research project is Beescape, which allows users to explore the stressors affecting bees in their own communities.
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Agriculture & Food
| 2,020 |
January 21, 2020
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https://www.sciencedaily.com/releases/2020/01/200121133319.htm
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Insect bites and warmer climate means double-trouble for plants
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Recent models are telling us that, as our climate warms up, herbivores and pests will cause increased damage to agricultural crops. One study predicted that crop yield lost to insects increases 10 to 25 percent for every 1 degree Celsius increase.
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Michigan State University scientists think that these models are incomplete and that we may be underestimating the losses. A new study shows that infested tomato plants, in their efforts to fight off caterpillars, don't adapt well to rising temperatures. This double-edged sword worsens their productivity.According to the study, two factors are at play. The first is rising temperatures. Insect metabolism speeds up with heat and they eat more. Also, warmer temperatures could open up a wider range of hospitable habitats to insects.Second, and this is what current models ignore, is how the infested plants react to the heat."We know that there are constraints that prevent plants from dealing with two stresses simultaneously," said Gregg Howe, University Distinguished Professor at the MSU-DOE Plant Research Laboratory. "In this case, little is known about how plants cope with increased temperature and insect attack at the same time, so we wanted to try and fill that gap."Plants have systems to deal with different threats. Caterpillar attack? There is a system for that. When a caterpillar takes a bite off a leaf, the plant produces a hormone, called Jasmonate, or JA. JA tells the plant to quickly produce defense compounds to thwart the caterpillar.Temperatures too hot? Overheated crops have another bag of tricks to cool themselves down. Obviously, they can't make a run for the inviting shade under a tree. They lift their leaves away from the hot soil. They also "sweat" by opening their stomata -- similar to skin pores -- so that water can evaporate to cool the leaves.Nathan Havko, a postdoctoral researcher in the Howe lab, had a breakthrough when he grew tomato plants in hot growth chambers, which are kept at 38 degrees Celsius. He also let hungry caterpillars loose on them."I was shocked when I opened the doors to the growth chamber where the two sets of plants were growing at 'normal' and 'high' temperatures," Howe said. "The caterpillars in the warmer space were much bigger; they had almost wiped the plant out.""When temperatures are higher, a wounded tomato plant cranks out even more JA, leading to a stronger defense response," Havko said. "Somehow, that does not deter the caterpillars. Moreover, we found that JA blocks the plant's ability to cool itself down, it can't lift its leaves or sweat."Perhaps, the plants close their pores to stop losing water from the wounded sites, but they end up suffering the equivalent of a heat stroke. It's even possible that the caterpillars are crafty and do extra damage to keep the leaf pores closed and leaf temperatures elevated, which will speed up the insect's growth and development.And, there are consequences."We see photosynthesis, which is how crops produce biomass, is strongly impaired in these plants," Havko said. "The resources to produce biomass are there, but somehow they aren't used properly and crop productivity decreases."There are many open questions to be resolved but, as of right now, the study suggests that when global temperatures rise, plants might have too many balls to juggle."I think we have yet to appreciate the unexpected tradeoffs between defense responses and plant productivity, especially when other types of environmental stress are present," Howe said. "Turning on the defense response may do more harm than good if the plants face high temperatures or other stresses."The study is published in the journal
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Agriculture & Food
| 2,020 |
January 17, 2020
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https://www.sciencedaily.com/releases/2020/01/200117080838.htm
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Human ancestors may have eaten hard plant tissues without damaging teeth
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Go ahead, take a big bite.
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Hard plant foods may have made up a larger part of early human ancestors' diet than currently presumed, according to a new experimental study of modern tooth enamel from Washington University in St. Louis.Scientists often look at microscopic damage to teeth to infer what an animal was eating. This new research -- using experiments looking at microscopic interactions between food particles and enamel -- demonstrates that even the hardest plant tissues scarcely wear down primate teeth. The results have implications for reconstructing diet, and potentially for our interpretation of the fossil record of human evolution, researchers said."We found that hard plant tissues such as the shells of nuts and seeds barely influence microwear textures on teeth," said Adam van Casteren, lecturer in biological anthropology in Arts & Sciences, the first author of the new study in Traditionally, eating hard foods is thought to damage teeth by producing microscopic pits. "But if teeth don't demonstrate elaborate pits and scars, this doesn't necessarily rule out the consumption of hard food items," van Casteren said.Humans diverged from non-human apes about seven million years ago in Africa. The new study addresses an ongoing debate surrounding what some early human ancestors, the australopiths, were eating. These hominin species had very large teeth and jaws, and likely huge chewing muscles."All these morphological attributes seem to indicate they had the ability to produce large bite forces, and therefore likely chomped down on a diet of hard or bulky food items such as nuts, seeds or underground resources like tubers," van Casteren said.But most fossil australopith teeth don't show the kind of microscopic wear that would be expected in this scenario.The researchers decided to test it out.Previous mechanical experiments had shown how grit -- literally, pieces of quartz rock -- produces deep scratches on flat tooth surfaces, using a device that mimicked the microscopic interactions of particles on teeth. But there was little to no experimental data on what happens to tooth enamel when it comes in contact with actual woody plant material.For this study, the researchers attached tiny pieces of seed shells to a probe that they dragged across enamel from a Bornean orangutan molar tooth.They made 16 "slides" representing contacts between the enamel and three different seed shells from woody plants that are part of modern primate diets. The researchers dragged the seeds against enamel at forces comparable to any chewing action.The seed fragments made no large pits, scratches or fractures in the enamel, the researchers found. There were a few shallow grooves, but the scientists saw nothing that indicated that hard plant tissues could contribute meaningfully to dental microwear. The seed fragments themselves, however, showed signs of degradation from being rubbed against the enamel.This information is useful for anthropologists who are left with only fossils to try to reconstruct ancient diets."Our approach is not to look for correlations between the types of microscopic marks on teeth and foods being eaten -- but instead to understand the underlying mechanics of how these scars on tooth surface are formed," van Casteren said. "If we can fathom these fundamental concepts, we can generate more accurate pictures of what fossil hominins were eating."So those big australopith jaws could have been put to use chewing on large amounts of seeds -- without scarring teeth."And that makes perfect sense in terms of the shape of their teeth" said Peter Lucas, a co-author at the Smithsonian Tropical Research Institute, "because the blunt low-cusped form of their molars are ideal for that purpose.""When consuming many very small hard seeds, large bite forces are likely to be required to mill all the grains," van Casteren said. "In the light of our new findings, it is plausible that small, hard objects like grass seeds or sedge nutlets were a dietary resource for early hominins."
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Agriculture & Food
| 2,020 |
January 16, 2020
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https://www.sciencedaily.com/releases/2020/01/200116141717.htm
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New model shows how crop rotation helps combat plant pests
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A new computational model shows how different patterns of crop rotation -- planting different crops at different times in the same field -- can impact long-term yield when the crops are threatened by plant pathogens. Maria Bargués-Ribera and Chaitanya Gokhale of the Max Planck Institute for Evolutionary Biology in Germany present the model in
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The continual evolution of plant pathogens poses a threat to agriculture worldwide. Previous research has shown that crop rotation can help improve pest control and soil quality. Other research shows that switching the environment in which a pathogen grows can limit its reproduction and change its evolution. However, these two concepts have been rarely studied together from an evolutionary point of view.To better understand how crop rotation can protect against pests, Bargués-Ribera and Gokhale developed a computational model of the technique that integrates evolutionary theory. They used the model to investigate a scenario in which cash crops (grown for profit) and cover crops (grown to benefit soil) are alternated, but are affected by a pathogen that only attacks the cash crops.The analysis identified which patterns of crop rotation maximize crop yield over multiple decades under the given scenario, revealing that regular rotations that switch every other year may not be optimal. The findings suggest that the long-term outcome of crop rotation depends on its ability to both maintain soil quality and diminish pathogen load during harvesting seasons."Our model is an example of how evolutionary theory can complement farmers' knowledge," Bargués-Ribera says. "In a world with ever increasing food demand, ecological and evolutionary principles can be leveraged to design strategies making agriculture efficient and sustainable."Future research could apply the new model to specific species to assess crop rotation patterns for specific crops and their pests. The model could also be used to help study the combined effects of crop rotation and other pest control techniques, such as fungicides and use of crops that have been genetically modified for pest resistance.
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Agriculture & Food
| 2,020 |
January 16, 2020
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https://www.sciencedaily.com/releases/2020/01/200116121843.htm
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Scientists uncover how an explosion of new genes explain the origin of land plants
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The new study, led by scientists from the universities of Bristol and Essex and published today [16 January] in
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Plants constitute one of the major lineages of life and are the basis of almost all ecosystems, being an important source of food and oxygen. During evolution, all organisms gain new genes, lose old ones, or simply recycle genes.The research team set out to understand which changes, at the genetic level, took place during the evolutionary transition of plants by comparing over 200 genomes, one of the largest datasets ever assembled to tackle the evolution of the plant kingdom.Using sophisticated computer techniques enabled the researchers to essentially travel back in time 470 million years ago to find out which genes were present in the first land-based plants as they evolved from living in water to land.Dr Jordi Paps, Lecturer from Bristol's School of Biological Sciences and lead researcher, explained: "After comparing over 200 genomes of the plant kingdom, we discovered that the origin of land plants is associated with two explosions of new genes, an unprecedented level of genomic novelty. Our findings challenge previous views of this transition being more gradual at genetic level."The first burst predates the origin of land plants, before they left their aquatic environments, and comprises genes that explain why plants are multicellular. The second coincides with the origin of land plants, and involved genes related to adaptations to challenges found in terrestrial environments."The team now plans to use the same approach to identify drought-resistant genes in crops.Dr Paps added: "We now plan to use the same approach to further explore the genes involved in drought tolerance. Most crops are sensitive to drought conditions, using our methods we can find genes involved in drought resistance that we can potentially introduce in dessication-sensitive plants."
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Agriculture & Food
| 2,020 |
January 15, 2020
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https://www.sciencedaily.com/releases/2020/01/200115191523.htm
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Lame sheep adjust their behavior to cope with their condition
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In the first study of its kind, published today in the
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The technology was developed by Dr Jasmeet Kaler, Associate Professor in Epidemiology and Farm Animal Health from the University, along with industry giant Intel and agricultural software developer Farm Wizard.Lameness is the biggest health and welfare problem on sheep farms, costing the sector around £80m a year. More than 90% of farmers in the UK report lameness in their flocks, most of which is caused by foot rot -- a bacterial infection. If spotted early enough, it can prevent the problem spreading in the flock.As sheep are a 'prey' species they are likely to mask signs of lameness when they feel threatened, or enlivened by the presence of observing farmers and vets. It means that up to now, diagnosis has been difficult and relies on visual inspection because there are no validated commercial tools available.The smart wearable technology consists of a sensing device worn on a sheep's ear tag that gathers accelerometer and gyroscope date effectively tracking the animal's behaviour and movement and its way of walking. The algorithms are used to create different alerts for farmers. What is particularly novel about the technology is that it uses edge processing which means it doesn't need to send all the data to the Cloud because it does the thinking on the device, which helps with battery life.For all three activities (standing, walking and lying), the study has identified features that differed between lame and non-lame sheep. This is particularly novel in lying and standing, which has unobvious lameness related behaviors which it would be difficult to spot with the human eye previously.The results suggest that instead of affecting how much of an activity lame sheep do, it shows that they actually carry out activities differently, leading to a change in acceleration and rotational movement.Detecting features that significantly differentiate lame from non-lame was not surprising because of visual differences previously reported between the gait pattern of lame and non-lame sheep. Five out of the top six characteristics when walking, were frequency, linked to rhythm and pace. These differences could be linked to reduced mobility because of the disease in lame sheep, which also resulted in differences in the regularity and frequency of head movements.Lame sheep also showed a change in gait with peculiar head nodding in line with stride compared to non-lame sheep which had a smoother stride pattern.A particularly interesting find, was that the results for classification of lameness had a higher accuracy within lying and standing activities.The top features include a mixture of frequency and time-domain features, this suggests differences in in the variability and smoothness of movements for both standing and lying down between lame and non-lame sheep. In lame sheep this could be an attempt by the animal to reduce discomfort caused by the lameness. Where they redistribute their body weight to an unaffected leg leading to postural changes when standing.The research also suggests that lame sheep possibly lie differently than non-lame ones, this could once again be due to the animal's attempt to alleviate the pain.Dr Kaler said: "Our study has shown conclusively that there are behavioural differences between lame and non-lame sheep when walking, standing and lying. This has been first report of its kind and given lameness classification is possible within all these activities this helps to improve the accuracy as well as flexibility in terms of energy requirements. This automated system for the lameness detection can help improve sheep health and welfare on farms."
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Agriculture & Food
| 2,020 |
January 15, 2020
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https://www.sciencedaily.com/releases/2020/01/200115093433.htm
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Nitrogen-fixing genes could help grow more food using fewer resources
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Scientists have transferred a collection of genes into plant-colonizing bacteria that let them draw nitrogen from the air and turn it into ammonia, a natural fertilizer.
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The work could help farmers around the world use less human-made fertilizers to grow important food crops like wheat, corn, and soybeans.The group of scientists, including two from Washington State University, published the study "Control of nitrogen fixation in bacteria that associate with cereals" late last month in "There's a growing interest in reducing the amount of fertilizer used in agriculture because it's expensive, has negative environmental impacts, and takes a lot of energy to make," said John Peters, Director of WSU's Institute of Biological Chemistry and a co-author on the paper. "There's a huge benefit to developing ways to increase the contributions of biological nitrogen fixation for crop production around the world."The team's research helps share a symbiotic benefit found in legume crops, which farmers have relied on for centuries to naturally enrich the soil.Legume crops, such as chickpeas and lentils, require significantly less fertilizer than other crops, because they've developed a symbiotic relationship with bacteria that grow within their root tissues. These bacteria convert nitrogen gas to ammonia through a process called biological nitrogen fixation.Bacteria take nitrogen from the air and convert it into ammonia for the plants, which use it for energy to grow. The plants in turn provide carbon and other nutrients to the microbes.To work symbiotically, legumes and microbes have evolved to release signals that each can understand. The plants give off chemicals that signal to the bacteria when they need fixed nitrogen. The bacteria produce similar signals to let the plants know when they need carbon.To develop a synthetic method for this symbiosis between other bacteria and crops, scientists worked to determine the groups of genes in bacteria that enable nitrogen fixing, then add those gene groups into other bacteria."This is just one step, although a large step, on the road to figuring out how to promote increasing contribution of biological nitrogen fixation for crop production," Peters said.Peters and WSU are co-leads on the overall project with his colleague Philip Poole at the University of Oxford in the UK.Reducing fertilizer requirements could have massive impacts on food availability, energy use and agriculture costs all over the world.Fertilizers are too expensive for many farmers around the world. Without them, many nutritionally valuable foods won't grow in many areas due to nitrogen-poor soil."This project is aimed at increasing food production and helping feed the world," Peters said. "Transforming food production to work without nitrogen-based fertilizers could be a huge development in underdeveloped countries. Adding these microbes would be like pouring kombucha on roots."Peters' lab specializes in studying metabolic processes in bacteria, or how they create and use energy. His lab provided a blueprint for how nitrogen fixation works in different organisms. Then his co-authors, synthetic biologists at the Massachusetts Institute of Technology, can create the mechanisms that microbes and plants will need."This is such a complex and wide-spread challenge it really takes a large team with varied areas of expertise to solve," Peters said. "But if we succeed, the reward could be huge for the entire planet."The project has been funded the National Science Foundation and the Biotechnology and Biological Sciences Research Council in the UK.
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Agriculture & Food
| 2,020 |
January 15, 2020
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https://www.sciencedaily.com/releases/2020/01/200115075617.htm
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Are sinking soils in the Everglades related to climate change?
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Characterized by alligators, airboats and catfish, the Everglades is a region of swampy wetlands in southern Florida. In addition to the area's role in Florida's tourism industry, the Everglades play a significant part in protecting our environment -- through carbon sequestration.
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Over a quarter of the Everglades are encompassed in the Everglades Agricultural Area. The Everglades Agricultural Area includes 700,000 acres of farmland where sugar cane, winter vegetables and other crops are grown.The farmland was created by draining the Everglades, starting over 100 years ago. There are four main canals that drain the area. Farmers also have systems of ditches to manage the water levels in their fields and to provide irrigation to crops.Since the 1950s, scientists have been studying an environmental change in the Everglades, called soil subsidence. Soil subsidence is the sinking or settling of the earth's surface. Researchers estimate a subsidence rate of about 1 inch per year.Soil subsidence is a growing problem. In recent years, soils around the Everglades are so shallow that farmers are struggling to manage water and grow crops.Previously, it was not clear if carbon quality played a role in soil subsidence. So, Andres Rodriguez, a researcher at University of Florida, was ready to find out. Ultimately, Rodriguez and his team want to improve soil conservation and explore different water management strategies. This research is important to protect the Everglades Agricultural Area, which plays a large role in Florida's agriculture economy.Carbon sequestration is a process where carbon from the atmosphere is stored in the soil, which helps lessen global warming. Plants, ocean, and the soil all capture and store carbon.The soil of the Everglades, called peat, is largely made up of waterlogged, decomposing plant and animal materials. The peat soil stores a large amount of carbon compared to other soils across the globe.When the Everglades Agricultural Area was drained, the soil was exposed to higher levels of oxygen. Decomposition of the plant and animal materials happens much faster with more oxygen. When the carbon in the soil decomposes, it becomes carbon dioxide gas. The mass of the soil decreases, and gas goes into the atmosphere. It's a big chemistry equation."It's not easy to picture a soil that disappears," says Rodriguez. "The most challenging process I have to explain -- and the most striking -- is how carbon in the soil goes from the soil to the atmosphere."The process of soil subsidence can release significant amounts of greenhouse gasses. This can have connections with climate change."To improve soil conservation, I recommend farmers avoid using short flood cycles," says Rodriguez. "I also suggest they use a crop rotation with rice during the summer." These practices decrease the amount of oxygen reaching the soil, which minimizes decomposition.He also encourages increasing soil carbon by adding plant material back into the soil. Farmers can do this by incorporating residue from sugarcane harvest into the soil. "I am aware that the practices I recommend present challenges from the agronomic point of view, but I am confident they can be sorted." Says Rodriguez.Rodriguez presented his research at the November International Annual Meeting of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America in San Antonio. This research was funded by the Soil and Water Sciences Department and the Everglades Research and Education Center at the University of Florida.
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Agriculture & Food
| 2,020 |
January 14, 2020
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https://www.sciencedaily.com/releases/2020/01/200114101706.htm
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Global diets are converging, with benefits and problems
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Research carried out by the University of Kent has shown that diets are changing in complex ways worldwide. International food supply patterns are supporting healthier diets in parts of the world, but causing underweight and obesity elsewhere. They are also having important effects on environmental sustainability, with potentially worrying consequences.
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Dr James Bentham, Lecturer in Statistics at Kent's School of Mathematics, Statistics and Actuarial Science, led the research alongside Professor Majid Ezzati from the School of Public Health at Imperial College London and other UK and international colleagues. The researchers carried out the study analysing food supply data for 171 countries from the 1960's to 2010's.The team discovered that South Korea, China and Taiwan have experienced the largest changes in food supply over the past five decades, with animal source foods such as meat and eggs, sugar, vegetables, seafood and oilcrops all becoming a much larger proportion of diet. In contrast, in many Western countries the supply of animal source foods and sugar has declined, particularly in high-income English-speaking countries such as the UK, US, Canada and Australia. The researchers also found that many countries around the world have seen an increase in vegetable-based diets. The sub-Saharan Africa region showed the least change, with a lack of diverse food supply, and this could be an explanation for the region's malnutrition.The declines in diets based on animal source foods and sugar and corresponding increases in vegetable availability indicate a possible trend towards more balanced and healthier foods in some parts of the world. However, in South Korea, China and Taiwan in particular, the increase in animal source and sugar availability has occurred at the same time as a dramatic rise in obesity, and also suggests that changes in diet may be having a substantial negative effect on the environment.Dr Bentham said: 'There are clear shifts in global food supply, and these trends may be responsible for strong improvements in nutrition in some parts of the world. However, obesity remains a long-term concern, and we hope that our research will open doors to analysis of the health impacts of global diet patterns. Equally, we must also consider carefully the environmental impacts of these trends.'Professor Ezzati added: 'Advances in science and technology, together with growing incomes, have allowed many nations to have access to a diversity of foods. We must harness these advances and set in place policies that provide healthier foods for people everywhere, especially those who can currently least afford them.'
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Agriculture & Food
| 2,020 |
January 13, 2020
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https://www.sciencedaily.com/releases/2020/01/200113153335.htm
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Nanosatellites improve detection of early-season corn nitrogen stress
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For corn growers, the decision of when and how much nitrogen fertilizer to apply is a perennial challenge. Scientists at the University of Illinois have shown that nanosatellites known as CubeSats can detect nitrogen stress early in the season, potentially giving farmers a chance to plan in-season nitrogen fertilizer applications and alleviate nutrient stress for crops.
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"Using this technology, we can possibly see the nitrogen stress early on, before tasseling. That means farmers won't need to wait until the end of the season to see the impact of their nitrogen application decisions," says Kaiyu Guan, assistant professor in the Department of Natural Resources and Environmental Sciences at the University of Illinois, and Blue Waters professor at the National Center for Supercomputing Applications. He is also principal investigator on a new study published in Being able to detect and address changes in crop nutrient status in real time is vitally important to avoid damage at critical periods and optimize yield. In general, existing satellite technology cannot achieve both high spatial resolution and high revisiting frequency (how often a given satellite comes back to the same spot above the Earth). Alternatively, drones can detect nutrient status in real time, but they usually can only cover local areas; thus, their utility is limited in scale.CubeSats bridge the gap between existing satellite technology and drones. With more than 100 of the relatively tiny satellites currently in orbit, Guan says, "CubeSats from Planet get down to a 3-meter resolution and revisit the same location every few days. So, right now we can monitor crop nitrogen status in real time for a much broader area than drones."Guan and his collaborators tested the capabilities of both drones and CubeSats to detect changes in corn chlorophyll content, a proxy for the plant's nitrogen status. The researchers focused on an experimental field in Central Illinois during the 2017 field season. Corn in the field was nitrogen-stressed to varying degrees due to multiple nitrogen application rates and timings, including all nitrogen applied at planting, and split applications at several developmental stages.The analyzed field was one of several in a larger study looking at nitrogen rates and timing, set up by Emerson Nafziger, professor emeritus in the Department of Crop Sciences at Illinois and co-author on the study."The idea was to see how much effect timing and form of nitrogen fertilizer would have on yield. This study allows an evaluation of how well the imaging could capture yield responses to nitrogen applied at different rates and times," Nafziger says.The scientists compared images from drones and CubeSats, and their signals matched well with tissue nitrogen measurements taken from leaves in the field on a weekly basis. Both technologies were able to detect changes in chlorophyll contents with a similar degree of accuracy and at the same point in the season."This information generates timely and actionable insights related to nitrogen stress, and so could provide guidance for additional nitrogen application where it's needed," Guan says.The implications go beyond optimizing yield."The low cost of nitrogen fertilizer and high corn yield potential motivates farmers to apply extra nitrogen as 'insurance' against nitrogen deficiency that lowers yield. But applying more nitrogen than the crop requires is both a financial and environmental risk," says Yaping Cai, graduate student in Guan's research group and lead student author on the paper.Guan adds, "A better tool for fertilizer use, enabled through new satellite technology and ecosystem modeling, could ultimately help farmers to reduce cost, increase yield, and meanwhile reduce environmental footprint for a sustainable agricultural landscape."
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Agriculture & Food
| 2,020 |
January 13, 2020
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https://www.sciencedaily.com/releases/2020/01/200113111145.htm
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Atlantic circulation collapse could cut British crop farming
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Crop production in Britain will fall dramatically if climate change causes the collapse of a vital pattern of ocean currents, new research suggests.
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The Atlantic Meridional Overturning Circulation (AMOC) brings heat from the tropics, making Britain warmer and wetter than it would otherwise be.University of Exeter scientists show that, while warming Britain is expected to boost food production, if the AMOC collapses it would not just wipe out these gains but cause the "widespread cessation of arable (crop-growing) farming" across Britain.Such a collapse -- a climate change "tipping point" -- would leave Britain cooler, drier and unsuitable for many crops, the study says.The main problem would be reduced rainfall and, though irrigation could be used, the amount of water and the costs "appear to be prohibitive.""If the AMOC collapsed, we would expect to see much more dramatic change than is currently expected due to climate change," said Dr Paul Ritchie, of the University of Exeter."Such a collapse would reverse the effects of warming in Britain, creating an average temperature drop of 3.4°C and leading to a substantial reduction in rainfall (?123mm during the growing season)."These changes, especially the drying, could make most land unsuitable for arable farming."The study examines a "fast and early" collapse of the AMOC, which is considered "low-probability" at present -- though the AMOC has weakened by an estimated 15% over the last 50 years.Professor Tim Lenton, Director of the Global Systems Institute at the University of Exeter, said worst-case scenarios must be considered when calculating risks."Any risk assessment needs to get a handle on the large impacts if such a tipping point is reached, even if it is a low-probability event" he said."The point of this detailed study was to discover how stark the impacts of AMOC collapse could be."The study follows a recent paper by Lenton and colleagues warning of a possible "cascade" of inter-related tipping points.The new study reinforces the message that "we would be wise to act now to minimise the risk of passing climate tipping points" said Lenton.Growing crops is generally more profitable than using land as pasture for livestock rearing, but much of northern and western Britain is unsuitable for arable farming."With the land area suitable for arable farming expected to drop from 32% to 7% under AMOC collapse, we could see a major reduction in the value of agricultural output," said Professor Ian Bateman, of Exeter's Land, Environment, Economics and Policy Institute."In this scenario, we estimate a decrease of £346 million per year -- a reduction of over 10% in the net value of British farming."Speaking about the expectation that moderate warming would boost agricultural production in Britain, he added: "It's important to note that the wider effects for the UK and beyond will be very negative as import costs rise steeply and the costs of most goods climb."The study focusses on agriculture, but AMOC collapse and the resulting temperature drop could lead to a host of other economic costs for the UK.The AMOC is one reason that average temperatures in Britain are warmer than those of many places at similar latitudes. For example, Moscow and the southern extremes of Alaska are further south than Edinburgh.The paper, published in the inaugural issue of the journal
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Agriculture & Food
| 2,020 |
January 13, 2020
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https://www.sciencedaily.com/releases/2020/01/200113093732.htm
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Research identifies possible on/off switch for plant growth
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New research from UC Riverside identifies a protein that controls plant growth -- good news for an era in which crops can get crushed by climate change.
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Researchers found the protein, IRK, while looking for clues to the ways plant cells divide or expand. They discovered IRK in the roots cells of a plant related to mustard."When this protein is present, the root perceives a signal that tells cells not to divide," said Jaimie Van Norman, who led the study and is an assistant professor of plant sciences at UCR. "If we can get the plant to ignore those signals, we may be able to get it to grow in conditions where it might not otherwise."The team's work on IRK was recently published in There may be some instances in which farmers also want to limit plant growth. For example, keeping weeds small, or trying to pause crop growth until a severe storm passes. IRK can be instrumental for both goals."This discovery gives us another way to control growth," Van Norman said. "Understanding how the plant itself stops growth can also allow us to accelerate growth."So far, Van Norman's team has only tested the effects of turning off the IRK gene in Arabidopsis, the mustard relative. However, Van Norman said the IRK protein is also found in other crop plants.This research is notable not only for its potential impact on crop and food security, but also because roots have historically been less well studied than the above-ground parts of plants. This is likely due to the relatively inaccessible nature of roots, Van Norman said.However, the roots are critical for plant survival and for the production of above-ground plant organs such as leaves flowers and fruits. Therefore, understanding their function and development is critical in efforts to improve crop productivity.Previous research has examined the role of signals sent between cells up and down the plant from the roots up toward the shoots and vice versa. This study shows communication between cells across the root is important as well."There was a longstanding hypothesis that this type of horizontal communication between cells was important, and this work provides new evidence that it is," Van Norman said.Next, Van Norman is hoping to understand whether bigger roots survive stress better. Some of the biggest challenges to crops include drought and high levels of salinity in soils.Salts accumulate in soil both from natural and humanmade sources, such as fertilizers and salts in irrigation waters. If there is too much salt built up near the soil surface, it can prevent vital processes in plant growth and even cause crops to fail entirely.Out of an abundance of caution and without accurate salinity measurements, farmers have traditionally over-irrigated their fields to send salts into lower soil depths where they are less harmful to crops. However, this practice is being scrutinized as both the quantity and quality of water becomes scarcer."It may be the case that by understanding what happens when the IRK-producing gene is turned off, we can make root growth less sensitive to soil conditions that pose a threat to food security," Van Norman said.
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Agriculture & Food
| 2,020 |
January 9, 2020
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https://www.sciencedaily.com/releases/2020/01/200109112857.htm
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Plants' 'organic' wounds improve produce
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Texas A&M AgriLife Research scientists found benefits of insect leaf-wounding in fruit and vegetable production. Stress responses created in the fruits and vegetables initiated an increase in antioxidant compounds prior to harvest, making them healthier for human consumption.
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"Many studies in the past supported this idea, but many others showed no differences," said Luis Cisneros-Zevallos, Ph.D., AgriLife Research horticulture and food scientist in College Station and principal investigator for a study addressing this controversy. "In our study we proved that wounding leaves in plants like those caused by insects produce healthier organic fruit."View the original publication in "We conducted studies using strawberries as a crop model and applied various levels of wounding to the leaves a few days before harvesting the fruit. We found how several genes associated with sugar translocation and phenolic compound biosynthesis were overexpressed in the distant strawberry fruit," said Facundo Ibanez, Ph.D., an investigator for the project associated with the Instituto Nacional de Investigacion Agropecuaria, Uruguay.All plants have the ability to respond to the environment by activating the secondary metabolism as part of a defense mechanism or as part of an adaptation process. It also activates the primary metabolism, which will move the carbon source needed to produce those antioxidant compounds, explained Cisneros-Zevallos."There was the existing idea proposed by others that insects present in the field in organic farming could cause a stress response in the plant and increase antioxidant compounds," said Cisneros-Zevallos. "However, this hypothesis or concept was never tested until now, where we mimicked the damage caused by insects."Ibanez said the study emphasized fresh produce as an excellent source of health-promoting compounds and that perhaps insects in some way can be allies to achieve even healthier produce."Healthier grown produce for the food industry can be a driving force for large-scale production and an attractive investment to relevant stakeholders," he said.Organic farming in recent years has experienced continued growth and a higher demand among consumers. This has had a positive large-scale impact on the organic industry, farmers and other industries related to organic produce, said Cisneros-Zevallos.After several studies published in the past on post-harvest wounding stress effects on different crops, the team was inspired to apply this approach to leaf surfaces in the field that mimicked the attack of insects to the plant."This observation was key when we designed the strategies to be used in the study, that simple wounding stress on leaf surfaces elicited this systemic response with the unique observation of higher accumulation of phenolic antioxidants in fruit," Ibanez said."Our team has elucidated a controversy that was an open question for many years," Cisneros-Zevallos said. "Understanding how these antioxidants are produced by a simple stress like wounding can certainly transform the way the fresh produce industry operates, including both organic and conventional. And it may allow the industry to adopt novel tools based on pre-harvest stress to favor the accumulation of healthier antioxidants in fresh produce and processed foods."
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Agriculture & Food
| 2,020 |
January 8, 2020
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https://www.sciencedaily.com/releases/2020/01/200108102257.htm
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Most meat eaters support veganism as 'ethical' and good for the environment
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A recently published study that looked at public opinion on plant-based diets has found widespread support for the ethics and environmental benefits of veganism and vegetarianism among meat eaters, but finds that the barriers are practical matters of taste, price, and convenience.
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Analysis published in the journal By contrast, over 80% of respondents thought veganism was not easy, 77% thought it 'inconvenient' and over 60% thought it was not enjoyable. Attitudes from respondents towards vegetarianism were significantly more positive on almost all counts.The study, which involved 1,000 men and women with an average age of 34, was conducted in September 2018. Participants were recruited online through the survey platform Prolific. The work was partially funded by the charity Viva! as part of Chris Bryant's ESRC PhD. His research is focused on shifting preferences away from animal consumption in view of climate change and reducing animal suffering.Chris Bryant from Bath's Department of Psychology explains: "At a time of year when many people are considering switching to plant-based diets with 'Veganuary', this study shows that most people already agree with the ethics of veganism and are aware of the benefits of vegan diets to the environment."That many people agree with the principles of veganism is one thing, but in terms of changing behaviours we need to acknowledge that for many it has been seen as too expensive, inconvenient and a sacrifice in terms of taste."Interestingly, in the time since this study was conducted, these things have all changed substantially. Supermarkets, restaurants, and even fast food outlets have developed numerous high quality and affordable vegan options. Having direct replacements for the foods people know and like makes it easier for everybody to consume fewer animal products. If we are to reduce animal product consumption in the UK and around the world, the development of high quality affordable alternatives to animal products is key."January marks the start of Veganuary, the annual campaign which last year inspired over a million people to try vegan diets for January and beyond.Earlier this month, the fast food bakery Greggs launched a vegan steak bake. This follows the introduction of Subway's vegan Meatball Marinara sub and even a vegan KFC burger.
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Agriculture & Food
| 2,020 |
January 8, 2020
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https://www.sciencedaily.com/releases/2020/01/200108074807.htm
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LED lighting in greenhouses helps but standards are needed
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While LED lighting can enhance plant growth in greenhouses, standards are needed to determine the optimal intensity and colors of light, according to Rutgers research that could help improve the energy efficiency of horticultural lighting products.
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Many lighting companies market their LED (light-emitting diode) products with claims of delivering an optimal "light recipe" that often consists of a combination of wavelengths and color ratios, such as a 4-to-1 red to blue ratio on the spectrum (colors of a rainbow). Plant scientists often use this information to evaluate the potential effects of lamps on plant growth and development. But standardized procedures on how to calculate these ratios are lacking, according to a study soon to be published in the journal Acta Horticulturae."The more efficient supplemental lighting sources are, the less electric power growers need to finish their crops," said senior author A.J. Both, a professor and extension specialist in controlled environment engineering in the Department of Environmental Sciences in the School of Environmental and Biological Sciences at Rutgers University-New Brunswick. "We hope to help make indoor crop production more sustainable and affordable."Increased energy efficiency can have a big impact on the bottom line, and information about new crop lighting strategies will help the burgeoning indoor farming industry, Both said.In greenhouses and controlled environments, electric lamps are used to supplement sunlight and extend lighting times to produce horticultural crops, such as vegetables, flowers and herbs, according to a previous study led by Both. Recent advances in energy-efficient LED technology provide the horticultural industry with multiple lighting options. But growers can't easily compare technologies and LED options because of a lack of independent data on how lamps perform. That study led to a proposed standardized product label allowing for comparisons of lamps across manufacturers.Both and colleagues continue to focus on independently assessing performance metrics such as power consumption, efficiency, light intensity and the light distribution pattern and relaying that information to commercial growers. Recent advancements have provided opportunities to precisely control the light from LED lamps and study their impacts on plant growth and development, according to Both's research. Both and his team work closely with plant scientists who study the impact of light on plants grown for food or ornamental crops.The new study recommends using a spectroradiometer, an instrument that measures light output across a specific range of wavelengths. Using such an instrument, various light ratios can be calculated. The researchers reported substantial differences in light ratios comparing sunlight with common lamps, including LED, high-pressure sodium, incandescent and fluorescent lamps used for plant lighting. The researchers hope that their work will contribute to the development of standard definitions for specific wavebands (ranges of wavelengths) that are important for plant growth and development.The lead author of the new study is Timothy Shelford, a part-time research specialist at Rutgers who also works at Cornell University. Claude Wallace, a Rutgers graduate and part-time employee, also contributed to the study.
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Agriculture & Food
| 2,020 |
January 8, 2020
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https://www.sciencedaily.com/releases/2020/01/200108074757.htm
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Drones effective tools for fruit farmers
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People have used the phrase "drone on and on" for a long time. Webster's dictionary defines this figure of speech as "to speak for a long time in a dull voice without saying anything interesting."
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Yet, in agriculture, drones aren't dull, at all!Farmers use drones to be more efficient. Drones help farmers improve yields and stay ahead of problems before they become too big.Olga Walsh, University of Idaho, is researching the use of drones for fruit trees. Most of the agricultural applications for drones -- or, more technically unmanned aerial vehicles (UAV) -- have been on grain crops like wheat, corn and soy."Adoption and use of crop sensors in production agriculture saves thousands of dollars every year in many crops," says Walsh. "Crop sensors also help to significantly improve the efficiency of agricultural inputs, such as fertilizers and water. Finally, drones can minimize negative impacts of agricultural activities on environmental quality."In Idaho, the fruit industry grows grapes, cranberries, apples, and even alternative fruits like Asian pears. Apples are the largest fruit crop in Idaho, with over 60 million pounds of apples produced per year.1Walsh's research team focused on applying UAV technology to fruit trees. Her previous work has been with wheat and other crops. "We know drones can be used in orchards," says Walsh. "But there aren't any grower recommendations regarding what data needs to be collected and what kind of data is most useful, depending on the grower objective."The most promising ways the drones could be employed for the orchards and tree nurseries are:Like with other uses of drones in agriculture, Walsh's work helps to collect detailed information about the crops, faster than humans could by physically "scouting" the fields. "The UAVs are capable of acquiring images with high resolutions that are ideal for detecting various crop issues," says Walsh."The UAV systems allow scanning the crops from above. They obtain high quality images and high-resolution spectral data. This is correlated with plant growth, health, water and nutrient status, and can be used to estimate biomass production." All are indicators of potential yield.It's not just about the speed of scouting a field. "Sensors can function within regions of the electromagnetic spectrum where human eyes can't," says Walsh. "Sensors are much more reliable and objective than visual assessment. They provide quantitative information (numeric data that can be measured and compared) versus qualitative information (descriptive data that can be observed)."Team members also perform outreach. "We conduct grower education on the use of remote sensing and using UAVs for crop monitoring," says Walsh. "We do demonstration flights and produce publications to boost grower adoption of precision agriculture methods.""The overall goal of this work is to strengthen sustainability and competitiveness of Idaho fruit tree producers," says Walsh. "Our findings increased awareness, knowledge, and adoption of crop sensors and UAVs."And, that's not dull at all!Walsh presented her work at the November International Annual Meeting of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America in San Antonio. Funding for this project came from the Idaho State Department of Agriculture Nursery Advisory and Florist Advisory Committee.1.
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Agriculture & Food
| 2,020 |
January 7, 2020
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https://www.sciencedaily.com/releases/2020/01/200107170110.htm
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Research team traces evolution of the domesticated tomato
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In a new paper, a team of evolutionary biologists and geneticists led by senior author associate professor Ana Caicedo, with first author Hamid Razifard at the University of Massachusetts Amherst, and others, report that they have identified missing links in the tomato's evolution from a wild blueberry-sized fruit in South America to the larger modern tomato of today.
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The missing link that deserves more attention than it has gotten to date, they say, is one of a number of intermediate variants between the fully wild and fully domesticated tomato. Results of their genetic studies indicate that the modern cultivated tomato is most closely related to a weed-like tomato group still found in Mexico rather than to semi-domesticated intermediate types found in South America.Razifard, a postdoctoral researcher in the Caicedo lab, says, "What's new is that we propose that about 7,000 years ago, these weedy tomatoes may have been re-domesticated into the cultivated tomato." The common cultivated tomato is the world's highest value and most widely grown vegetable crop and an important model for studying fruit development, Caicedo and colleagues point out.In this work, part of a larger research effort supported by the National Science Foundation and led by Esther van der Knaap at the University of Georgia, the researchers say that for many years an oversimplified view of tomato domestication was thought to involve two major transitions, the first from small, wild Solanum pimpinellifolium L. (SP) to a semi-domesticated intermediate, S. lycoperiscum L. var. cerasiforme (SLC). The second was a transition from an intermediate group (SLC) to fully domesticated cultivated tomato (S. lycopersicum L. var. lycopersicum (SLL)).Their genetic studies address the role of what they call a "historically contentious" and complex intermediate stage of tomato domestication, an essential chapter that should not be overlooked in the tomato's long journey from wildness to domestication. Details appear in an Advanced Access edition of Razifard and colleagues, who created a public genomic variants dataset for this study, used whole-genome sequencing of wild, intermediate and domesticated (SP, SLC, and SLL) varieties, plus population genomic analyses to reconstruct tomato domestication, focusing on evolutionary changes especially in the intermediate stages (SLC). They generated new whole-genome sequences for 166 samples, with particular attention to intermediate variants from its native range and cultivated fruit from Mexico, previously under-represented in studies.Razifard says, "We found that SLC may have originated in Ecuador around 80,000 years ago as a wild species rather than a domesticate. It was cultivated in Peru and Ecuador by native people later to create medium-size tomato fruits. We also found that two subgroups from the intermediate group may have spread northward to Central America and Mexico possibly as a weedy companion to other crops.""Remarkably, these northward extensions of SLC seem to have lost some of the domestication-related phenotypes present in South America. They still grow in milpas of Mexico, where people use them as food although not cultivating them intentionally," he adds. Milpas are fields where farmers plant many different crops in the same area.He and Caicedo note that an origin of the domestic tomato from weed-like ancestors was proposed in 1948 based on the many native names that exist for the weed-like tomato, in contrast to fewer names for the common cultivated tomato. This hypothesis was challenged by others who argued against Mexico as a center of tomato domestication due to the absence of completely wild tomatoes there.Razifard says, "It's still a mystery how tomatoes have moved northward. All we have is genetic evidence and no archaeological evidence because tomato seeds don't preserve well in the archeological records."The researchers point out that exploring intermediate stages of tomato domestication has "direct implications for crop improvement." For example, they observed some signals of selection in certain intermediate populations for alleles involved in disease resistance and drought tolerance, important, Razifard says, "Such evidence is useful for finding candidate alleles that can be used for creating disease-resistant and/or drought-tolerant tomatoes." Other intermediate populations had higher beta-carotene or sugar content, attractive traits to consumers.The evolutionary biologist says, "This is the kind of paper that Darwin would have enjoyed reading. He drew many of his insights on evolution from studying plants, especially crops. He corresponded extensively with botanists before he finalized his theory of evolution through natural selection."A postdoctoral researcher who did much of the population genomic analyses for this project, Razifard adds that he wants to support the movement in biology against "plant blindness," the tendency to ignore the importance of plants in studying evolution as well as other subfields of biology. Also, he is from a minority Azerbaijani-speaking area of Iran and says, "This paper is special to me because it's my first one with a female-majority author list. I feel lucky to be part of a generation that is changing science, and I hope this paper serves as a model for gender equity in STEM fields."
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Agriculture & Food
| 2,020 |
January 6, 2020
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https://www.sciencedaily.com/releases/2020/01/200106141614.htm
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Specifying irrigation needs for container-grown plants
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A study at the University of Florida's Institute of Food and Agricultural Sciences examined the efficiency of irrigation schedules used for container-grown plants to determine if they could be improved with specific daily adjustments.
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Jeff Million and Tom Yeager conducted two experiments to monitor the effect of irrigation schedules on plant growth and water usage.The researchers present their findings in their article "Periodic Versus Real-time Adjustment of a Leaching Fraction-based Microirrigation Schedule for Container-grown Plants" published in the open-access journal The goal of efficient irrigation is to supply enough water for profitable production, but not so much that unnecessary leaching occurs. Million and Yeager determined that one method for monitoring irrigation efficiency under a wide range of production conditions is to note the amount of container drainage and then divide that by the amount of irrigation water applied to the container. The result is called the leaching fraction.The leaching fraction is defined as the degree of extra irrigation water that must be applied above the amount required by the crop in order to maintain acceptable substrate water content.Open-field production of 524,000 irrigated acres of horticultural plants in the United States used 205 billion gallons of water in a recent year. Fifty percent of this water was pumped from groundwater sources. These figures are concerning because water resources for irrigation are becoming increasingly limited -- technologies to conserve water are needed.Million and Yeager devised two experiments to determine if a leaching fraction-guided irrigation practice with fixed irrigation run times could be improved by using an evapotranspiration-based scheduling program to make additional adjustments to irrigation run times based on real-time weather information, including rain.Evapotranspiration is the process by which water is transferred from the land to the atmosphere by evaporation from the soil and by transpiration from plants.Although sprinkler irrigation is used to produce plants in small containers in high densities, direct application of water using spray-stake irrigation is used to produce plants in larger containers that are placed in low densities. Compared with in-ground production, container production of plants with sprinkler irrigation is inherently inefficient, as containers occupy only a fraction of the production area even when closely spaced.Direct application of water to the container with spray-stake irrigation can also be inefficient. Typical water delivery rates for spray-stakes are much higher than for typical sprinkler systems so that small changes in irrigation run times can equate to large changes in application volumes and higher chances of overwatering.Efficiency of spray-stake irrigation can be improved by using a cyclic irrigation system that applies water multiple times per day rather than relying on a single application.A tested irrigation system with pressure-compensating emitters applied irrigation uniformly and consistently, whereas in a nursery with large irrigated areas, irrigation water may be distributed less uniformly, and irrigation applications may be unpredictably skipped for a host of reasons.Million and Yeager used a medium-flow, down-spray emitter in a container that represented the smaller size of the range of containers that are typically in nurseries and production facilities. This likely resulted in a more efficient retention of water than would have occurred using the same spray-stake in a larger container.The researchers found that small daily adjustments to the amount of water applied based on evapotranspiration were not beneficial for saving water compared to adjustments made every 1 to 3 weeks, based on leaching fraction tests. The fact that plant growth was similar for all plants indicates, as Yeager adds, "the leaching fraction test provides a way to justify the amount of irrigation applied and the test is easy to conduct in the nursery."
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Agriculture & Food
| 2,020 |
January 6, 2020
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https://www.sciencedaily.com/releases/2020/01/200106141608.htm
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Genes controlling mycorrhizal colonization discovered in soybean
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Like most plants, soybeans pair up with soil fungi in a symbiotic mycorrhizal relationship. In exchange for a bit of sugar, the fungus acts as an extension of the root system to pull in more phosphorus, nitrogen, micronutrients, and water than the plant could on its own.
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Mycorrhizal fungi occur naturally in soil and are commercially available as soil inoculants, but new research from the University of Illinois suggests not all soybean genotypes respond the same way to their mycorrhizal relationships."In our study, root colonization by one mycorrhizal species differed significantly among genotypes and ranged from 11 to 70%," says Michelle Pawlowski, postdoctoral fellow in the Department of Crop Sciences at Illinois and co-author on a new study in To arrive at that finding, Pawlowski grew 350 diverse soybean genotypes in pots filled with spores of a common mycorrhizal fungus. After six weeks, she looked at the roots under a microscope to evaluate the level of colonization."It was a little bit of a gamble because we didn't know much about soybean's relationship with mycorrhizae and did not know if differences in colonization among the soybean genotypes would occur. So when we screened the soybean genotypes and found differences, it was a big relief," Pawlowski says. "That meant there was a potential to find genetic differences, too."The process of root colonization starts before fungal spores even germinate in the soil. Roots exude chemicals, triggering spores to germinate and grow toward the root. Once the fungus makes contact, there's a complex cascade of reactions in the plant that prevents the usual defensive attack against invading pathogens. Instead, the plant allows the fungus to enter and set up shop inside the root, where it creates tiny tree-like structures known as arbuscules; these are where the fungus and plant trade sugar and nutrients.The study suggests there is a genetic component to root colonization rates in soybean. To find it, Pawlowski compared the genomes of the 350 genotypes and honed in on six genomic regions associated with differing levels of colonization in soybean."We were able to use all the information we have on the soybean genome and gene expression to find possible causal genes within these six regions," she says.According to the study, the genes control chemical signals and pathways that call fungus toward roots, allow the plant to recognize mycorrhizal fungus as a "good guy," help build arbuscules, and more. "For almost every step in the colonization process, we were finding related genes within those regions," Pawlowski says.Knowing which genes control root colonization could lead breeders to develop soybean cultivars with a higher affinity for mycorrhizal fungus, which could mean improved nutrient uptake, drought tolerance, and disease resistance."This environmentally friendly approach to improving soybean production may also help reduce the overuse of fertilizers and pesticides and promote more holistic crop production systems," says Glen Hartman, plant pathologist in the Department of Crop Sciences and crop pathologist for USDA-ARS.
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Agriculture & Food
| 2,020 |
January 6, 2020
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https://www.sciencedaily.com/releases/2020/01/200106123443.htm
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Dogs and wolves are both good at cooperating
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A team of researchers have found that dogs and wolves are equally good at cooperating with partners to obtain a reward. When tested in same-species pairs, dogs and wolves proved equally successful and efficient at solving a given problem. This finding suggests that basic cooperation abilities were present in a common ancestor of dogs and wolves, and have not been lost in the domestication process.
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It is estimated that dogs were domesticated as much as 30,000 -- 40,000 years ago, and over that span of time they have undergone many changes from their wild counterparts, wolves. In a study published in the To test cooperation ability, the researchers created a test scenario that was designed to mimic a hunting situation, one in which multiple animals were trying to take down a larger herbivore, such as an elk or other horned prey. The concept was that, in the wild, one of the animals would need to draw the attention -- and the dangerous horns -- of the potential prey, so that the other could attack from the rear and bring the prey down. Thus the animal that took the most risk in the hunt also had to trust that it would be given a share of the reward in the end. The test apparatus involved a barrier separating the participants from a food reward, with two openings on opposite ends that were controlled by a researcher. When the first animal approached an opening, the door before it would shut while the opposite door remained open, allowing the partner to enter first and access the food. The door then remained open, so that other animal could then enter. Thus the animals had to cooperate in two ways -- first by positioning themselves on opposite ends of the barrier and then by timing and coordinating their approaches towards the barrier.The researchers found that the dogs and wolves were equally successful, succeeding in about three out of four trials on average. "Dogs were not outperformed by wolves in coordinating their actions, in the frequency of success or in how long the task took," explains Juliane Bräuer of the Max Planck Institute for the Science of Human History, lead author of the study and head of the DogStudies group at the institute. "This is somewhat surprising, as it contradicts recent findings by other researchers related to more complex cooperation tasks performed by dogs and wolves." The researchers hypothesize that this could be due to the simple nature of the task in the present study, which might require only basic cooperation skills.After solving the test, the pairs generally shared the food reward, but sharing was more likely when the dominant member of the pair was the second to arrive at the reward. "The probability of co-feeding during successful trials was higher when dominants 'took the risk,' so to speak, in moving first and drawing the closed door, because their higher rank gave them a higher chance to nonetheless get their share even if they accessed the food reward a few seconds after the subordinate," explains Bräuer. So while the researchers set out to test cooperation, it turned out that competition within the pair was also a factor.Interestingly, however, dogs and wolves seemed to differ in which animal in the pair was willing to move first, drawing the closed door and thus being second to the food. Dominant wolves seemed to be more willing to take on this task in general than dominant dogs, and did so more frequently the more times the pair shared food. Dominant dogs, on the other hand, apparently seem to prefer to wait for their partner to draw the closed door. As would be expected, the more times dogs shared food, the more likely the subordinate member of the pair was to move first and draw the closed door.The researchers point out that, although the kind of coordination shown in the present study may rely on more simple mechanisms than full, conscious cooperation, it can still inform us about how cooperative behavior might have changed -- or not -- during the domestication process. "Our results suggest that the abilities needed to coordinate actions were already present in the dog-wolf ancestor," notes Bräuer. "In future studies, it would be interesting to focus on the question of how exactly factors like social dynamics, living conditions, the type of task and maybe also breed differences influence the cooperative behavior of dogs and wolves."
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Agriculture & Food
| 2,020 |
January 6, 2020
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https://www.sciencedaily.com/releases/2020/01/200106122009.htm
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Processed foods highly correlated with obesity epidemic in the US
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As food consumed in the U.S. becomes more and more processed, obesity may become more prevalent. Through reviewing overall trends in food, George Washington University (GW) researcher Leigh A. Frame, PhD, MHS, concluded that detailed recommendations to improve diet quality and overall nutrition are needed for consumers, who are prioritizing food that is cheaper and more convenient, but also highly processed. Her conclusions are published in a review article in
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"When comparing the U.S. diet to the diet of those who live in "blue zones" -- areas with populations living to age 100 without chronic disease -- the differences are stark," said Frame, co-author of the article, program director for the Integrative Medicine Programs, executive director of the Office of Integrative Medicine and Health, and assistant professor of clinical research and leadership at the GW School of Medicine and Health Sciences. "Many of the food trends we reviewed are tied directly to a fast-paced U.S. lifestyle that contributes to the obesity epidemic we are now facing."The rising obesity epidemic in the U.S., as well as related chronic diseases, are correlated with a rise in ultra-processed food consumption. The foods most associated with weight gain include potato chips, sugar sweetened beverages, sweets and desserts, refined grains, red meats, and processed meats, while lower weight gain or even weight loss is associated with whole grains, fruits, and vegetables. Other food trends outlined in the report include insufficient dietary fiber intake, a dramatic increase in food additives like emulsifiers and gums, and a higher prevalence of obesity, particularly in women.In mice and in vitro trials, emulsifiers, found in processed foods, have been found to alter microbiome compositions, elevate fasting blood glucose, cause hyperphagia, increase weight gain and adiposity, and induce hepatic steatosis. Recent human trials have linked ultra-processed foods to decreased satiety (fullness), increased meal eating rates (speed), worsening biochemical markers, including inflammation and cholesterol, and more weight gain. In contrast, populations with low meat, high fiber, and minimally processed foods -- the "blue zones" -- have far less chronic diseases, obesity rates, and live longer disease-free."Rather than solely treating the symptoms of obesity and related diseases with medication, we need to include efforts to use food as medicine," said Frame. "Chronic disease in later years is not predestined, but heavily influenced by lifestyle and diet. Decreasing obesity and chronic disease in the U.S. will require limiting processed foods and increasing intake of whole vegetables, legumes, nuts, fruits, and water. Health care providers must also emphasize lifestyle medicine, moving beyond 'a pill for an ill.' "
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Agriculture & Food
| 2,020 |
January 6, 2020
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https://www.sciencedaily.com/releases/2020/01/200106121957.htm
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Researchers united on international road map to insect recovery
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It's no secret that many insects are struggling worldwide. But we could fix these insects' problems, according to more than 70 scientists from 21 countries. Their road map to insect conservation and recovery is published in
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The goal is to start insect recovery soon, says initiator Prof. Jeff Harvey from the Netherlands Institute of Ecology (NIOO-KNAW) and Vrije Universiteit Amsterdam. Evidence is growing that all over the world, insect species are suffering from multiple human-induced stress factors: habitat loss and fragmentation, pollution, invasive species, climate change and overharvesting. "As scientists, we want to gather all available knowledge and put it to action together with land managers, policy makers and everyone else involved."The roadmap is based on achieving targets over different timescales. More than 70 experts from all continents joined the effort, including book author Dave Goulson and leading scientist Hans de Kroon whose study on insect biomass decline is well-known. "Essentially, we are thinking strategically and this is novel," explains Harvey. "Now and down the road, all to reverse insect declines."Insect abundance, diversity and biomass are frequently under pressure. It affects all functional groups: from predators to pollinators. The scientists state that "insects are vitally important in a wide range of ecosystem services of which some are indispensible for food production and security, as in pest control."The steps to be taken are divided into immediate, mid- and long-term actions. First of all, there are a number of actions coined as 'no-regret solutions' that can be taken immediately and regardless of new knowledge still to come -- as they will not just benefit single insect species. Secondly, there is the urgent need to prioritise: which species, areas and issues need our attention the most.For the mid-term, new experiments should be planned to clarify which stress factors cause what effects. And to gain knowledge in understudied areas. A parallel action here would be to dig through existing insect collections, in museums for instance. "This can fill in gaps in our diversity data of the past, as an essential base of reference."Finally, more long-term actions would include the formation of public-private partnerships and sustainable financing initiatives to restore and create places to live for the insects. Combined with a global monitoring programme where people all use the exact same methods and sites, over longer timescales. "In that way, we can definitely compare the well-being of insects worldwide, and rule out possibly disruptive inconsistencies."The extensive group of scientific experts involved in the road map stresses that insect declines are a serious threat, one that society cannot postpone addressing any longer. Harvey: "Most importantly, we hope that end-users and land managers now can use this road map in for instance farming, habitat management and urban development as a template for true insect recovery."With more than 300 staff members and students, the Netherlands Institute of Ecology (NIOO-KNAW) is one of the largest research institutes of the Royal Netherlands Academy of Arts and Sciences (KNAW). The institute specialises in water and land ecology. As of 2011, the institute is located in an innovative and sustainable research building in Wageningen, the Netherlands. NIOO has an impressive research history that stretches back 60 years and spans the entire country, and beyond.
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Agriculture & Food
| 2,020 |
January 2, 2020
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https://www.sciencedaily.com/releases/2020/01/200102143425.htm
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Climate change and deforestation could decimate Madagascar's rainforest habitat by 2070
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A study in
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Madagascar -- a biodiversity hotspot where 80 to 90% of its animal and plant species are exclusive to the area -- has been devasted by decades of deforestation and overharvesting. The activities have destroyed much of the land cover that provides habitat for a variety of unique animals, including currently endangered varieties of lemurs. In particular, two species of ruffed lemurs are now critically endangered, and these animals play a central role in dispersing the seeds of a number of plant species that provide food and shelter for other animals across the rainforest."Because of their essential role as seed dispersers and their sensitivity to habitat degradation, ruffed lemurs serve as a critical indicator of the health of Madagascar's entire eastern rainforest," said Andrea Baden, a professor of anthropology at The Graduate Center, CUNY and Hunter College and the study's primary investigator. "When we projected the impact of deforestation and climate change, we found that deforestation alone and climate change alone could reduce ruffed lemur habitat by over 50%. Even more alarming, these two factors together are projected to essentially decimate suitable rainforest habitat by the end of the century."The researchers' data suggest that the speed and intensity of destruction to Madagascar's eastern rainforest will be greatly determined by whether the country institutes strict protections against deforestation or a relaxed set of policies. Protecting forested areas that provide shelter to ruffed lemurs and serve as corridor links to their strongholds is particularly important to survival given their role as a keystone species that enables the survival of a large number of animal and plant species in one of the world's most biodiverse regions."The results from our study will be useful to nonprofit organizations, park management, and the broader conservation community," Baden said. "Our results indicate potential conservation opportunities for ruffed lemurs and any of the rainforest-dwellers that rely on forest cover and connectivity. Protected areas are vital to species persistence."
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Agriculture & Food
| 2,020 |
January 2, 2020
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https://www.sciencedaily.com/releases/2020/01/200102143357.htm
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Craft-beer boom linked to record-number of US states growing hops
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Craft breweries aren't just a fun place to meet up with friends. They may be fueling an unprecedented geographic expansion of hop production across the U.S., according to researchers at Penn State and The University of Toledo. Their findings suggest that as more craft breweries emerge around the country, so may new opportunities for farmers.
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Hops are a key ingredient in beer production, providing aroma and bittering characteristics. Before 2007, hop production in the U.S. was limited to only three Pacific Northwest states -- Oregon, Washington, and Idaho -- according to Claudia Schmidt, assistant professor of agricultural economics in Penn State's College of Agricultural Sciences. Citing a report released this year by the Hop Growers of America, she said that 29 states are now engaging in hop production."Our study is the first to systematically show that the number of hop farms in a state is related to the number of craft breweries," said Schmidt. "It suggests that in areas where hop production is possible and not cost-prohibitive, breweries are expanding markets for farmers and providing an opportunity to diversify farm income."Using data from the U.S. Census of Agriculture and ReferenceUSA, the researchers found that from 2007 to 2017, the number of breweries in the U.S. more than quadrupled from 992 to more than 4,000, and that the number of breweries in a state is associated with more hop farms and hop acres five years later. The number of hop farms grew from 68 to 817, and hop acreage expanded from 31,145 to 59,429 acres."This growth has not only led to interesting changes in the locations of hop farms across the U.S., but it has positioned the U.S. as the largest producer of hops globally, both in terms of acreage and production," said Elizabeth Dobis, a postdoctoral scholar at the Penn State-based Northeast Regional Center for Rural Development, and lead author of the study.Working with farm, brewery, and climate data, the researchers developed a statistical model to determine whether new craft breweries in a state between 2007 and 2017 resulted in a larger number of hop producers and hop acres planted, by both new and existing growers in that state. They built a time-lag into their model to identify the effect of new breweries over time. They also controlled for other variables that may influencefarmers to start growing hops, such as average farm size, average net farm income, and climate.Their findings, which were published recently in the One possible explanation for the trend is that the growing consumer demand for locally sourced food and beverages encourages craft brewers to seek out locally grown ingredients, said Schmidt."While most craft breweries serve a local market, they haven't always sourced local ingredients for their beers," Schmidt said. "But if you're a brewer looking to differentiate yourself in an increasingly crowded market, sourcing ingredients locally is an approach that some brewers have found to be effective."For example, in a project unrelated to this study, Penn State Extension's Kristy Borrelli and Maria Graziani conducted focus groups with Pennsylvania craft brewers, who reported that sourcing ingredients locally helps them connect with their customers' sense of place and preference for a flavor profile that is unique to the region.If more brewers are looking for hops grown nearby, then more farmers may be willing to try growing them, even if only on a small scale. For instance, in Pennsylvania only 17 farms reported hop production in 2017, and their combined acreage is small -- only 21 acres in all, according to the U.S. Census of Agriculture.Looking forward, the researchers said that they will collaborate with Penn State Extension to identify the specific attributes and price points that Pennsylvania craft brewers are looking for in order to help inform farmers' production decisions.
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Agriculture & Food
| 2,020 |
December 30, 2019
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https://www.sciencedaily.com/releases/2019/12/191230104753.htm
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Long-dormant disease becomes most dominant foliar disease in New York onion crops
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New York is the fifth largest producer of onion bulbs in the United States, producing over 110,000 metric tons from over 2,800 hectares. Most of these onions are grown on high organic matter soils, where foliar disease management is crucial to productivity and profitability. These foliar diseases include Botrytis leaf blight, purple blotch, downy mildew, and Stemphylium leaf blight.
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Stemphylium leaf blight (SLB) initially appears as small, tan to brown lesions that coalesce and extend the length of the leaves. These lesions become dark olive brown to black, contributing to the loss of green leaf area, which may affect bulb size and quality and prevents the plant tops from lodging naturally when the bulbs are fully matured.Until recently, SLB has been considered a minor foliar disease as it has not done much damage in New York since the early 1990s. However, onion growers in New York have recently seen an increase in the dieback of their crops, and scientists at Cornell University were surprised to discover that SLB was the cause."We set out to determine the cause of the dieback problem," said Frank Hay, one of the Cornell University scientists. "A surprise was that Stemphylium leaf blight had long been considered a minor disease of onion but had become the dominant foliar disease in New York onion crops."Hay and his colleagues discovered that the re-emergence of SLB occurred as the disease developed resistance to fungicides. Their research has resulted in the removal of some fungicides from commercial production as widespread field resistance has developed.
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Agriculture & Food
| 2,019 |
December 24, 2019
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https://www.sciencedaily.com/releases/2019/12/191224085707.htm
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'Lost crops' could have fed as many as maize
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Make some room in the garden, you storied three sisters: the winter squash, climbing beans and the vegetable we know as corn. Grown together, newly examined "lost crops" could have produced enough seed to feed as many indigenous people as traditionally grown maize, according to new research from Washington University in St. Louis.
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But there are no written or oral histories to describe them. The domesticated forms of the lost crops are thought to be extinct.Writing in the Growing goosefoot (Archaeologists found the first evidence of the lost crops in rock shelters in Kentucky and Arkansas in the 1930s. Seed caches and dried leaves were their only clues. Over the past 25 years, pioneering research by Gayle Fritz, professor emerita of archaeology at Washington University, helped to establish the fact that a previously unknown crop complex had supported local societies for millennia before maize -- a.k.a. corn -- was adopted as a staple crop.But how, exactly, to grow them?The lost crops include a small but diverse group of native grasses, seed plants, squashes and sunflowers -- of which only the squashes and sunflowers are still cultivated. For the rest, there is plenty of evidence that the lost crops were purposefully tended -- not just harvested from free-living stands in the wild -- but there are no instructions left."There are many Native American practitioners of ethnobotanical knowledge: farmers and people who know about medicinal plants, and people who know about wild foods. Their knowledge is really important," Mueller said. "But as far as we know, there aren't any people who hold knowledge about the lost crops and how they were grown."It's possible that there are communities or individuals who have knowledge about these plants, and it just isn't published or known by the academic community," she said. "But the way that I look at it, we can't talk to the people who grew these crops."So our group of people who are working with the living plants is trying to participate in the same kind of ecosystem that they participated in -- and trying to reconstruct their experience that way."That means no greenhouse, no pesticides and no special fertilizers."You have not just the plants but also everything else that comes along with them, like the bugs that are pollinating them and the pests that are eating them. The diseases that affect them. The animals that they attract, and the seed dispersers," Mueller said. "There are all of these different kinds of ecological elements to the system, and we can interact with all of them."Her new paper reported on two experiments designed to investigate germination requirements and yields for the lost crops.Mueller discovered that a polyculture of goosefoot and erect knotweed is more productive than either grown separately as a monoculture. Grown together, the two plants have higher yields than global averages for closely related domesticated crops (think: quinoa and buckwheat), and they are within the range of those for traditionally grown maize."The main reason that I'm really interested in yield is because there's a debate within archeology about why these plants were abandoned," Mueller said. "We haven't had a lot of evidence about it one way or the other. But a lot of people have just kind of assumed that maize would be a lot more productive because we grow maize now, and it's known to be one of the most productive crops in the world per unit area."Mueller wanted to quantify yield in this experiment so that she could directly compare yield for these plants to maize for the first time.But it didn't work out perfectly. She was only able to obtain yield estimates for two of the five lost crops that she tried to grow -- but not for the plants known as maygrass, little barley and sumpweed.Reporting on the partial batch was still important to her."My colleagues and I, we're motivated from the standpoint of wanting to see more diverse agricultural systems, wanting to see the knowledge and management of indigenous people recognized and curiosity about what the ecosystems of North America were like before we had this industrial agricultural system," Mueller said.
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Agriculture & Food
| 2,019 |
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