In an analysis piece on Nature, the director of CIMMYT’s Global Wheat Program, Alison Bentley, highlights the expected income of the Russia-Ukraine war on food security.
In low-income nations, the ability of governments to continue to subsidize bread will be strained; the knock-on effects on overall government spending and provision of public services will reach far beyond wheat. The last time wheat prices increased sharply, in 2008, it precipitated food riots from Burkina Faso to Bangladesh.
An unprecedented level of international political and economic action is now required to safeguard the immediate food supply of those who are already vulnerable, including in the global south. At the same time, a range of agricultural interventions must be deployed to make the supply of wheat more resilient in the years ahead.
At the same time, climate change has likely slowed breeding progress for high-yielding, broadly adapted wheat, according to the new study, published recently in Nature Plants.
“Breeders are usually optimistic, overlooking many climate change factors when selecting,” said Matthew Reynolds, wheat physiologist at the International Maize and Wheat Improvement Center (CIMMYT) and co-author of the publication. “Our findings undermine this optimism and show that the amplified interaction of wheat lines with the environment due to climate change has made it harder for breeders to identify outstanding, broadly adapted lines.”
What do 10 million data points tell scientists?
Each year for nearly half a century, wheat breeders taking part in the CIMMYT-led International Wheat Improvement Network (IWIN) have tested approximately 1,000 new, experimental wheat lines and varieties at some 700 field sites in over 90 countries.
Promising lines are taken up by wheat breeding programs worldwide, while data from the trials is used to guide global breeding and other critical wheat research, explained Wei Xiong, CIMMYT crop modeler/physiologist based in China and lead author of the new paper.
“To date, this global testing network has collected over 10 million data points, while delivering wheat germplasm estimated to be worth several billion dollars annually in extra productivity to hundreds of millions of farmers in less developed countries,” Xiong said.
Xiong and his colleagues analyzed “crossover interactions” — changes in the relative rankings of pairs of wheat lines — in 38 years of data from four kinds of wheat breeding trials, looking for the extent to which climate change or breeding progress have flipped those rankings. Two of the trials whose data they examined focused on yield in bread wheat and durum wheat, while the other two assessed wheat lines’ performance under high temperatures and in semi-arid environments, respectively.
In addition to raising yields, wheat breeders are endowing the crop with added resilience for rising temperatures.
“We found that warmer and more erratic climates since the 1980s have increased ranking changes in global wheat breeding by as much as 15 percent,” Xiong said. “This has made it harder for breeders to identify superior, broadly adapted lines and even led to scientists discarding potentially useful lines.”
Conversely, wheat cultivars emerging from breeding for tolerance to environmental stresses, particularly heat, are showing substantially more stable yields across a range of environments and fostering wheat’s adaptation to current, warmer climates, while opening opportunities for larger and faster genetic gains in the future, according to the study.
“Among other things, our findings argue for more targeted wheat breeding and testing to address rapidly shifting and unpredictable farming conditions,” Reynolds added.
Grafting wheat shoot to oat root gives the plant tolerance to a disease called “Take-all,” caused by a pathogen in soil. The white arrow shows the graft junction. (Photo: Julian Hibberd)
Grafting is the technique of joining the shoot of one plant with the root of another, so they continue to grow together as one. Until now it was thought impossible to graft grass-like plants in the group known as monocotyledons because they lack a specific tissue type, called the vascular cambium, in their stem.
Researchers at the University of Cambridge have discovered that root and shoot tissues taken from the seeds of monocotyledonous grasses — representing their earliest embryonic stages — fuse efficiently. Their results are published today in the journal Nature.
An estimated 60,000 plants are monocotyledons; many are crops that are cultivated at enormous scale, for example rice, wheat and barley.
The finding has implications for the control of serious soil-borne pathogens including Panama Disease, or Tropical Race 4, which has been destroying banana plantations for over 30 years. A recent acceleration in the spread of this disease has prompted fears of global banana shortages.
“We’ve achieved something that everyone said was impossible. Grafting embryonic tissue holds real potential across a range of grass-like species. We found that even distantly related species, separated by deep evolutionary time, are graft compatible,” said Julian Hibberd in the University of Cambridge’s Department of Plant Sciences, senior author of the report.
The technique allows monocotyledons of the same species, and of two different species, to be grafted effectively. Grafting genetically different root and shoot tissues can result in a plant with new traits — ranging from dwarf shoots, to pest and disease resistance.
Alison Bentley, CIMMYT Global Wheat Program Director and a contributor to the report, sees great potential for the grafting method to be applied to monocot crops grown by resource-poor farmers in the Global South. “From our major cereals, wheat and rice, to bananas and matoke, this technology could change the way we think about adapting food security crops to increasing disease pressures and changing climates.”
High magnification images show successful grafting of wheat in which a connective vein forms between root and shoot tissue after four months. White arrows show the graft junction. (Photo: Julian Hibberd)Monocotyledons breakthrough
The scientists found that the technique was effective in a range of monocotyledonous crop plants including pineapple, banana, onion, tequila agave and date palm. This was confirmed through various tests, including the injection of fluorescent dye into the plant roots — from where it was seen to move up the plant and across the graft junction.
“I read back over decades of research papers on grafting and everybody said that it couldn’t be done in monocots. I was stubborn enough to keep going — for years — until I proved them wrong,” said Greg Reeves, a Gates Cambridge Scholar in the University of Cambridge Department of Plant Sciences, and first author of the paper.
“It’s an urgent challenge to make important food crops resistant to the diseases that are destroying them,” Reeves explained. “Our technique allows us to add disease resistance, or other beneficial properties like salt-tolerance, to grass-like plants without resorting to genetic modification or lengthy breeding programmes.”
The world’s banana industry is based on a single variety, called the Cavendish banana — a clone that can withstand long-distance transportation. With no genetic diversity between plants, the crop has little disease-resilience. And Cavendish bananas are sterile, so disease resistance cannot be bred into future generations of the plant. Research groups around the world are trying to find a way to stop Panama Disease before it becomes even more widespread.
Image of date palm two and a half years after grafting. Inset shows a magnified region at the base of the plant, with the arrowhead pointing to the graft junction. (Photo: Julian Hibberd)
Grafting has been used widely since antiquity in another plant group called the dicotyledons. Dicotyledonous orchard crops — including apples and cherries, and high-value annual crops including tomatoes and cucumbers — are routinely produced on grafted plants because the process confers beneficial properties, such as disease resistance or earlier flowering.
The researchers have filed a patent for their grafting technique through Cambridge Enterprise. They have also received funding from Ceres Agri-Tech, a knowledge exchange partnership between five leading universities in the United Kingdom and three renowned agricultural research institutes.
“Panama disease is a huge problem threatening bananas across the world. It’s fantastic that the University of Cambridge has the opportunity to play a role in saving such an important food crop,” said Louise Sutherland, Director of Ceres Agri-Tech.
Ceres Agri-Tech, led by the University of Cambridge, was created and managed by Cambridge Enterprise. It has provided translational funding as well as commercialisation expertise and support to the project, to scale up the technique and improve its efficiency.
This research was funded by the Gates Cambridge Scholarship programme.
The University of Cambridge is one of the world’s top ten leading universities, with a rich history of radical thinking dating back to 1209. Its mission is to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence.
The University comprises 31 autonomous Colleges and 150 departments, faculties and institutions. Its 24,450 student body includes more than 9,000 international students from 147 countries. In 2020, 70.6% of its new undergraduate students were from state schools and 21.6% from economically disadvantaged areas.
Cambridge research spans almost every discipline, from science, technology, engineering and medicine through to the arts, humanities and social sciences, with multi-disciplinary teams working to address major global challenges. Its researchers provide academic leadership, develop strategic partnerships and collaborate with colleagues worldwide.
The University sits at the heart of the ‘Cambridge cluster’, in which more than 5,300 knowledge-intensive firms employ more than 67,000 people and generate £18 billion in turnover. Cambridge has the highest number of patent applications per 100,000 residents in the UK.
The International Maize and Wheat Improvement Center (CIMMYT) is the global leader in publicly-funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of the CGIAR System and leads the CGIAR Research Programs on Maize and Wheat and the Excellence in Breeding Platform. The Center receives support from national governments, foundations, development banks and other public and private agencies.
Cover photo: A banana producer in Kenya. (Photo: N. Palmer/CIAT)
Researchers from the International Maize and Wheat Improvement Center (CIMMYT) and the International Livestock Research Institute (ILRI) have identified new genomic regions associated with maize stover quality, an important by-product of maize which can be used in animal feed.
The results of the study, published this month in Nature Scientific Reports, will allow maize breeders to select for stover quality traits more quickly and cost-effectively, and to develop new dual purpose maize varieties without sacrificing grain yield.
The researchers screened diverse Asia-adapted CIMMYT maize lines from breeders’ working germplasm for animal feed quality traits. They then used these as a reference set to predict the breeding values of over a thousand doubled haploid lines derived from abiotic stress breeding programs based on genetic information. Based on these breeding values, the scientists further selected 100 of these double haploid lines and validated the performance of stover quality traits through field-based phenotyping.
The results demonstrate the feasibility of incorporating genomic prediction as a tool to improve stover traits, circumventing the need for field or lab-based phenotyping. The findings significantly reduce the need for additional testing resources — a major hindrance in breeding dual-purpose maize varieties.
Interestingly, the researchers found that increased animal feed quality in maize stover had no impact on grain yield, a concern raised by scientists in the past.
“The main purpose of this study and overall purpose of this CIMMYT and ILRI collaboration was to optimize the potential of maize crops for farm families, increase income, improve livelihoods and sustainably manage the crop livestock system, within limited resources,” said P.H. Zaidi, a maize physiologist at CIMMYT and co-author of the study.
“More than 70% of the farmers in the tropics are smallholders so they don’t have a lot of land to grow crops for grain purposes and separate stover for animal feed, so this is a very sustainable model if they grow dual purpose maize.”
By growing maize simultaneously for both human consumption and animal feed, farmers can get the most out of their crops and conserve natural resources like land and water.
A farmer works in a maize field close to the Pusa site of the Borlaug Institute for South Asia (BISA), in the Indian state of Bihar. (Photo: M. DeFreese/CIMMYT)
Fodder for thought
The findings from this study also validate the use of genomic prediction as an important breeding tool to accelerate the development and improvement of dual-purpose maize varieties, according to CIMMYT Maize Breeder and first author of the study, M.T. Vinayan.
With the demand for animal feed increasing around the world, crop scientists and breeders have been exploring more efficient ways to improve animal feed quality in cereals without compromising grain yields for human consumption.
“Not all maize varieties have good stover quality, which is what we realized when we started working on this project. However, we discovered that there are a few which offer just as good quality as sorghum stover — a major source of livestock fodder particularly in countries such as India,” said Zaidi.
The publication of the study is a fitting tribute to the late Michael Blummel, who was a principal scientist and deputy program leader in the feed and forage development program at ILRI and co-author of this study.
“A couple of years back Dr Blummel relocated from the Hyderabad office at ILRI to its headquarters at Addis Ababa, but he used to frequently visit Hyderabad, and without fail met with us on each visit to discuss updates, especially about dual-purpose maize work. He was very passionate about dual-purpose maize research with a strong belief that the additional income from maize stover at no additional cost will significantly improve the income of maize farmers,” Zaidi said. “Michael was following this publication very closely because it was the first of its kind in terms of molecular breeding for dual purpose maize. He would have been very excited to see this published.”
A farmer in Morogoro, Tanzania, discusses differences in his maize ears caused by differences in on-farm conditions. (Photo: Anne Wangalachi/CIMMYT)
Global climate change represents an existential threat to many of the world’s most vulnerable farmers, introducing new stresses and amplifying the unpredictability and risk inherent in farming. In low- and middle-income countries that are heavily reliant on domestic production, this increased risk and unpredictability threatens disastrous consequences for the food security and wellbeing of rural and urban populations alike.
Given the stakes, substantial investments have been made towards developing climate-resilient crops. But what happens when the innovations widely considered to be beneficial don’t gain traction on the ground, among those who stand to lose the most from inaction? What can researchers, policymakers and funders do to ensure that the most vulnerable rural populations don’t lose out on the benefits?
These are the questions posed by a new scoping review co-authored by Kevin Pixley, interim deputy director general for research and partnerships and director of the Genetic Resources Program at the International Maize and Wheat Improvement Center (CIMMYT).
The paper relies on a descriptive analysis of 202 studies from the past 30 years which assess the determinants of climate-resilient crop adoption by small-scale producers in low- and middle-income countries. These were identified through an extensive search and screening process of multiple academic databases and grey literature sources, and selected from an initial pool of over 6,000 articles.
Taking stock
The authors identified interventions determining adoption across the literature surveyed. A key theme which emerged was the need for context-sensitive technical and financial support for climate-resilient crop adoption. Nearly 16% of the studies found that adoption depended on access to relevant extension programs. Around 12% identified access to credit and other financial instruments as key, while a further 12% identified the implementation of community programs supporting climate-resilient crops as a determining factor.
However, the study stresses that there are no one-size-fits-all solutions. Increased adoption of climate-resilient agricultural innovations will depend on interventions being highly context informed. For example, the review shows that while some studies identified older farmers as more reluctant to adopt new technologies, an equal number of studies found the opposite.
Moreover, the review identified important opportunities for further research. Gender-based approaches, for example, remain a blind spot in the literature. The majority of studies reviewed only included women if they were household heads, thus overlooking the role they may play in influencing the adoption of new agricultural technologies in male-headed households.
A community-based seed producer in Kiboko, Kenya, inspects her crop of drought-tolerant maize. (Photo: Anne Wangalachi/CIMMYT)
Driving evidence-based policymaking
The review was published as part of a collection of 10 research papers produced as part of Ceres2030: Sustainable Solutions to End Hunger. The project, a partnership between Cornell University, the International Food Policy Research Institute (IFPRI) and the International Institute for Sustainable Development (IISD), distills decades of scientific and development research into a clear menu of policy options for funders committed to achieving the UN’s Sustainable Development Goal 2: Ending world hunger by 2030.
Speaking at a German government event on achieving Sustainable Development Goal 2, Bill Gates praised the Ceres2030 initiative, noting that “nothing on this scale has ever been done because we lacked the tools to analyze this complex information. But with the new research, solid evidence will drive better policymaking.”
He went on to highlight the CGIAR’s leadership role in these efforts, saying: “The CGIAR system is a key global institution that is investing in these approaches. It’s a critical example of how innovation can lead the way.”
A new study analyzing the diversity of almost 80,000 wheat accessions reveals consequences and opportunities of selection footprints. (Photo: Keith Ewing)
Researchers working on the Seeds of Discovery (SeeD) initiative, which aims to facilitate the effective use of genetic diversity of maize and wheat, have genetically characterized 79,191 samples of wheat from the germplasm banks of the International Maize and Wheat Improvement Center (CIMMYT) and the International Center for Agricultural Research in the Dry Areas (ICARDA).
The findings of the study published today in Nature Communications are described as “a massive-scale genotyping and diversity analysis” of the two types of wheat grown globally — bread and pasta wheat — and of 27 known wild species.
Wheat is the most widely grown crop globally, with an annual production exceeding 600 million tons. Approximately 95% of the grain produced corresponds to bread wheat and the remaining 5% to durum or pasta wheat.
The main objective of the study was to characterize the genetic diversity of CIMMYT and ICARDA’s internationally available collections, which are considered the largest in the world. The researchers aimed to understand this diversity by mapping genetic variants to identify useful genes for wheat breeding.
From germplasm bank to breadbasket
The results show distinct biological groupings within bread wheats and suggest that a large proportion of the genetic diversity present in landraces has not been used to develop new high-yielding, resilient and nutritious varieties.
“The analysis of the bread wheat accessions reveals that relatively little of the diversity available in the landraces has been used in modern breeding, and this offers an opportunity to find untapped valuable variation for the development of new varieties from these landraces”, said Carolina Sansaloni, high-throughput genotyping and sequencing specialist at CIMMYT, who led the research team.
The study also found that the genetic diversity of pasta wheat is better represented in the modern varieties, with the exception of a subgroup of samples from Ethiopia.
The researchers mapped the genomic data obtained from the genotyping of the wheat samples to pinpoint the physical and genetic positions of molecular markers associated with characteristics that are present in both types of wheat and in the crop’s wild relatives.
According to Sansaloni, on average, 72% of the markers obtained are uniquely placed on three molecular reference maps and around half of these are in interesting regions with genes that control specific characteristics of value to breeders, farmers and consumers, such as heat and drought tolerance, yield potential and protein content.
Open access
The data, analysis and visualization tools of the study are freely available to the scientific community for advancing wheat research and breeding worldwide.
“These resources should be useful in gene discovery, cloning, marker development, genomic prediction or selection, marker-assisted selection, genome wide association studies and other applications,” Sansaloni said.
The study was part of the SeeD and MasAgro projects and the CGIAR Research Program on Wheat (WHEAT), with the support of Mexico’s Secretariat of Agriculture and Rural Development (SADER), the United Kingdom’s Biotechnology and Biological Sciences Research Council (BBSRC), and CGIAR Trust Fund Contributors. Research and analysis was conducted in collaboration with the National Institute of Agricultural Botany (NIAB) and the James Hutton Institute (JHI).
About CIMMYT:
The International Maize and What Improvement Center (CIMMYT) is the global leader in publicly-funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of the CGIAR System and leads the CGIAR programs on Maize and Wheat and the Excellence in Breeding Platform. The Center receives support from national governments, foundations, development banks and other public and private agencies. For more information visit staging.cimmyt.org.
Elite wheat varieties at CIMMYT’s experimental station in Ciudad Obregon, in Mexico’s Sonora state. (Photo: Marcia MacNeil/CIMMYT)
In a new study, scientists have found that genome segments from a wild grass are present in more than one in five of elite bread wheat lines developed by the International Maize and Wheat Improvement Center (CIMMYT).
Scientists at CIMMYT and other research institutes have been crossing wild goat grass with durum wheat — the wheat used for pasta — since the 1980s, with the help of complex laboratory manipulations. The new variety, known as synthetic hexaploid wheat, boosts the genetic diversity and resilience of wheat, notoriously vulnerable due to its low genetic diversity, adding novel genes for disease resistance, nutritional quality and heat and drought tolerance.
The study, which aimed to measure the effect of these long-term efforts using state-of-the-art molecular technology, also found that 20% of CIMMYT modern wheat lines contain an average of 15% of the genome segments from the wild goat grass.
“We’ve estimated that one-fifth of the elite wheat breeding lines entered in international yield trials has at least some contribution from goat grass,” said Umesh Rosyara, genomic breeder at CIMMYT and first author of the paper, which was published in Nature Scientific Reports. “This is much higher than expected.”
Although the synthetic wheat process can help bring much-needed diversity to modern wheat, crossing with synthetic wheat is a complicated process that also introduces undesirable traits, which must later be eliminated during the breeding process.
“Many breeding programs hesitate to use wild relatives because undesirable genomic segments are transferred in addition to desirable segments,” said Rosyara. “The study results can help us devise an approach to quickly eliminate undesirable segments while maintaining desirable diversity.”
CIMMYT breeding contributions are present in nearly half the wheat sown worldwide, many of such successful cultivars have synthetic wheat in the background, so the real world the impact is remarkable, according to Rosyara.
“With this retrospective look at the development and use of synthetic wheat, we can now say with certainty that the best wheat lines selected over the past 30 years are benefiting from the genes of wheat’s wild relatives,” he explained. “Even more, using cutting-edge molecular marker technology, we should be able to target and capture the most useful genes from wild sources and better harness this rich source of diversity.”
Modern breeders tread in nature’s footsteps
The common bread wheat we know today arose when an ancient grain called emmer wheat naturally cross-bred with goat grass around 10,000 years ago. During this natural crossing, very few goat grass genes crossed over, and as a result, current bread wheat is low in diversity for the genome contributed by goat grass. Inedible and considered a weed, goat grass still has desirable traits including disease resistance and tolerance to climate stresses.
Scientists sought to broaden wheat’s genetic diversity by re-enacting the ancient, natural cross that gave rise to bread wheat, crossing improved durum wheat or primitive emmer with different variants of goat grass. The resulting synthetic wheats were crossed again with improved wheats to help remove undesirable wild genome segments.
Once synthetic wheat is developed, it can be readily crossed with any elite wheat lines thus serving as a bridge to transfer diversity from durum wheat and wild goat grass to bread wheat. This helps breeders develop high yielding varieties with desirable traits for quality varieties and broad adaption.
CIMMYT is the first to use wheat’s wild relatives on such a large scale, and the synthetic derivative lines have been used by breeding programs worldwide to develop popular and productive bread wheat varieties. One example, Chuanmai 42, released in China in 2003, stood as the leading wheat variety in the Sichuan Basin for over a decade. Other synthetic derivative lines such as Sokoll and Vorobey appear in the lineage of many successful wheat lines, contributing crucial yield stability — the ability to maintain high yields over time under varying conditions.
The successful, large-scale use of genes from wheat’s wild relatives has helped broaden the genetic diversity of modern, improved bread wheat nearly to the level of the crop’s heirloom varieties. This diversity is needed to combat future environmental, pest, and disease challenges to the production of a grain that provides 20% of the calories consumed by humans worldwide.
This work was supported by the CGIAR Research Program on Wheat (WHEAT) and Seeds of Discovery (SeeD), a multi-project initiative comprising MasAgro Biodiversidad, a joint initiative of CIMMYT and the Ministry of agriculture and rural development (SADER) through the MasAgro (Sustainable Modernization of Traditional Agriculture) project; the CGIAR Research Programs on Maize (MAIZE) and Wheat (WHEAT); and a computation infrastructure and data analysis project supported by the UK’s Biotechnology and Biological Sciences Research Council (BBSRC). CIMMYT’s worldwide partners participated in the evaluation of CIMMYT international wheat yield trials.
For more information, or to arrange interviews with the researchers, please contact:
About the CGIAR Research Program on Wheat
The CGIAR Research Program on Wheat (WHEAT) is led by the International Maize and Wheat Improvement Center (CIMMYT), with the International Center for Agricultural Research in the Dry Areas (ICARDA) as a primary research partner. Funding comes from CGIAR, national governments, foundations, development banks and other agencies, including the Australian Centre for International Agricultural Research (ACIAR), the UK Department for International Development (DFID) and the United States Agency for International Development (USAID).
About CIMMYT
The International Maize and Wheat Improvement Center (CIMMYT) is the global leader in publicly funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of CGIAR and leads the CGIAR Research Programs on Maize and Wheat, and the Excellence in Breeding Platform. The center receives support from national governments, foundations, development banks and other public and private agencies.
Farmer Gashu Lema’s son harvests improved variety “Kubsa” wheat, Gadulla village, Mojo, Ethiopia. (Photo: P. Lowe/CIMMYT/P. Lowe
A recent article in the journal Nature Plants validates the work of wheat breeders who produce yield-boosting varieties for farmers across a range of incomes and environments.
Based on a rigorous large-scale study spanning five decades of wheat breeding progress under cropping systems with low, medium and high fertilizer and chemical plant protection usage, the authors conclude that modern wheat breeding practices aimed at high-input farming systems have promoted genetic gains and yield stability across a wide range of environments and management conditions.
In other words, wheat breeding benefits not only large-scale and high-input farmers but also resource-poor, smallholder farmers who do not use large amounts of fertilizer, fungicide, and other inputs.
This finding underscores the efficiency of a centralized breeding effort to improve livelihoods across the globe – the philosophy behind the breeding programs of the International Maize and Wheat Improvement Center (CIMMYT) over the past 50 years.
It also contradicts a commonly held belief that breeding for intensive systems is detrimental to performance under more marginal growing environments, and refutes an argument by Green Revolution critics that breeding should be targeted to resource-poor farmers.
In a commentary published in the same Nature Plants issue, two CIMMYT scientists — Hans Braun, director of CIMMYT’s global wheat program and the CGIAR Research Program on Wheat, and Matthew Reynolds, CIMMYT wheat physiologist — note the significance of the study.
“Given that wheat is the most widely grown crop in the world, sown annually on around 220 million ha and providing approximately 20% of human calories and protein, the social and economic implications are large,“ they state.
Among other implications:
The study found that modern breeding has reduced groups of genes (haplotypes) with negative or neutral effects – a finding which will help breeders combine positive haplotypes in the future, including for hybrid breeding.
The study demonstrates the benefits of breeding for overall yield potential, which — given that wheat is grown over a wider range of environments, altitudes and latitudes than any other crop, with widely ranging agronomic inputs – has significant cost-saving implications.
Braun and Reynolds acknowledge that the longstanding beliefs challenged by this study have a range of influences, from concern about rural livelihoods, to the role of corporate agribusiness and the capacity of Earth’s natural resources to sustain 10 billion people.
While they welcome the conclusions as a validation of their work, they warn against seeing the study as “a rubber stamp for all things ‘high-input’” and encourage openness to new ideas as the need arises.
“If the climate worsens, as it seems destined to, we must certainly be open to new ways of doing business in crop improvement, while having the common sense to embrace proven technologies,” they conclude.
The reported work by wheat scientists paves the way for expanded use of wild grass species, such as Aegilops tauschii (also known as goat grass; pictured here) as sources of new genes for higher grain zinc in wheat. (Photo: CIMMYT)
An international team of scientists applied genome-wide association analysis for the first time to study the genetics that underlie grain zinc concentrations in wheat, according to a report published in Nature Scientific Reports on September 10.
Analyzing zinc concentrations in the grain of 330 bread wheat lines across diverse environments in India and Mexico, the researchers uncovered 39 new molecular markers associated with the trait, as well as two wheat genome segments that carry important genes for zinc uptake, translocation, and storage in wheat.
The findings promise greatly to ease development of wheat varieties with enhanced levels of zinc, a critical micronutrient lacking in the diets of many poor who depend on wheat-based food, according to Velu Govindan, wheat breeder at the International Maize and Wheat Improvement Center (CIMMYT) and first author of the new report.
“A collaboration among research centers in India, Australia, the USA and Mexico, this work will expedite breeding for higher zinc through use of ‘hotspot’ genome regions and molecular markers,” said Govindan. “It also advances efforts to make selection for grain zinc a standard feature of CIMMYT wheat breeding. Because varieties derived from CIMMYT breeding are grown on nearly half the world’s wheat lands, ‘mainstreaming’ high zinc in breeding programs could improve the micronutrient nutrition of millions.”
More than 17 percent of humans, largely across Africa and Asia, lack zinc in their diets, a factor responsible for the deaths of more than 400,000 young children each year.
Often used in human disease research, the genome-wide association approach was applied in this study to zero in on genome segments — known as quantitative trait loci (QTLs) — that carry genes of interest for wheat grain zinc content, according to Govindan.
“The advantages of the genome-wide association method over traditional QTL mapping include better coverage of alleles and the ability to include landraces, elite cultivars, and advanced breeding lines in the analysis,” he explained. “Our study fully opens the door for the expanded use of wheat progenitor species as sources of alleles for high grain zinc, and the outcomes helped us to identify other candidate genes from wheat, barley, Brachypodium grasses and rice.”
Farmers in South Asia are growing six zinc-enhanced wheat varieties developed using CIMMYT breeding lines and released in recent years, according to Ravi Singh, head of the CIMMYT Bread Wheat Improvement Program.
Financial support for this study was provided by HarvestPlus (www.HarvestPlus.org), a global alliance of agriculture and nutrition research institutions working to increase the micronutrient density of staple food crops through biofortification. The views expressed do not necessarily reflect those of HarvestPlus. It was also supported by CGIAR Funders, through the Research Program on Wheat and the Research Program on Agriculture for Nutrition and Health. Research partners in India and Pakistan greatly contributed to this study by conducting high-quality field trials.
At CIMMYT’s Science Week 2018, Nature Genetics Senior Editor Catherine Potenski spoke on how to publish plant genomics research that has broad, novel impact.
Catherine Potenski, Senior Editor of Nature Genetics, talks to participants of CIMMYT’s Science Week on June 26, 2018. (Photo: Alfonso Cortés/CIMMYT)
Having research that is high-impact is not only critical to doing excellent science that has meaning, but also a premier way to let the research community know what you are doing and reach a broader audience, according to Catherine Potenski, Senior Editor at Nature Genetics, one of the more than 70 high-quality academic journals of publishing company Springer Nature.
“Plant genomics is an exciting field that is a priority for Nature Genetics given climate change and other challenges,” said Potenski. “We look for studies with novelty, a genetics scope and resource value.”
Nature Genetics is highly selective and publishes approximately 200 papers per year. Potenski wants to make the editorial review process more productive and simple for researchers so they can share their best work.
“You should organize your paper to highlight the impact of the findings and write a cover letter that places your work in context, highlighting what gap of knowledge it fills and how others will use this research,” explained Potenski. In addition, scientists should target the right journal for their research. In case of doubt, they can send a pre-submission inquiry and work with editors.
Impact is not always immediate, and the impact factor is not necessarily a good or proven metric. “The first CRISPR articles published in the early 2000s are now very impactful, but nobody knew the impact they would have then. Just because it is not in a high-impact journal, it does not mean it is not high-impact,” she said.
Potenski shared the six questions plant researchers should ask themselves when submitting research to Nature Genetics.
Is my main approach genetic?
Your main analyses should be based on genetic screens, Quantitative Trait Locus (QTL) mapping, genome re-sequencing or other genetic approaches. If the main analysis of a paper is in transcriptomics, imaging or biochemistry, this could be considered off scope (but fine if they are secondary analyses).
Are the findings highly novel?
Your research should reflect a new method or finding that is really groundbreaking. Findings that just provide insight into a known process, are confirmatory or incremental do not meet Nature’s standards. If the finding is only new for a specific crop, that might also not be sufficiently novel.
Is there a large user group for the data?
Bigger is usually always better; you want your research to apply to or benefit as many people as possible. If the crop you are studying is widely consumed like wheat, or you have a large study scope such as large-scale GWAS (Genome-Wide Association Study) analysis, that will impact many more people than if you are studying watermelons using single QTL mapping.
Is this a very large or unique dataset?
You want large, high-quality datasets and analyses that are unique and other groups cannot easily repeat. Ideally this leads to a new approach in your field. Data that are open and easily available, and studies using the latest technologies also get priority.
Do the findings provide biological insights?
You want people reading your study to learn something new about plant biology. Instead of merely reporting domestication patterns, you want something new about the mechanisms of evolution or adaptation. Editors look for comprehensive, molecular mechanistic insight into the processes studied.
Is there evidence for crop improvement?
Editors prioritize studies with potential for crop improvement, especially in the context of climate change and food security. You want your research to be demonstrated in a crop plant, ideally in the physical plant and not in a model simulation.
