Shelves filled with maize seed samples make up the maize active collection at the germplasm bank at CIMMYT’s global headquarters in Texcoco, Mexico. It contains around 28,000 unique samples of maize seed â including more than 24,000 farmer landraces â and related species. (Photo: Xochiquetzal Fonseca/CIMMYT)
A new $25.7 million project, led by the International Maize and Wheat Improvement Center (CIMMYT), a Research Center part of CGIAR, the worldâs largest public sector agriculture research partnership, is expanding the use of biodiversity held in the worldâs genebanks to develop new climate-smart crop varieties for millions of small-scale farmers worldwide.
As climate change accelerates, agriculture will be increasingly affected by high temperatures, erratic rainfall, drought, flooding and sea-level rise. Looking to the trove of genetic material in genebanks, scientists believe they can enhance the resilience of food production by incorporating this diversity into new crop varieties â overcoming many of the barriers to fighting malnutrition and hunger around the world.
“Better crops can help small-scale farmers produce more food despite the challenges of climate change. Drought-resistant staple crops, such as maize and wheat, that ensure food amid water scarcity, and faster-growing, early-maturing varieties that produce good harvests in erratic growing seasons can make a world of difference for those who depend on agriculture. This is the potential for climate-adaptive breeding that lies untapped in CGIARâs genebanks,” said Claudia Sadoff, Managing Director, Research Delivery and Impact, and Executive Management Team Convener, CGIAR.
Over five years, the project, supported by the Bill & Melinda Gates Foundation, aims to identify plant accessions in genebanks that contain alleles, or gene variations, responsible for characteristics such as heat, drought or salt tolerance, and to facilitate their use in breeding climate-resilient crop varieties. Entitled Mining useful alleles for climate change adaptation from CGIAR genebanks, the project will enable breeders to more effectively and efficiently use genebank materials to develop climate-smart versions of important food crops, including cassava, maize, sorghum, cowpea and rice.
Wild rice. (Photo: IRRI)
The project is a key component of a broader initiative focused on increasing the value and use of CGIAR genebanks for climate resilience. It is one of a series of Innovation Sprints coordinated by the Agriculture Innovation Mission for Climate (AIM4C) initiative, which is led by the United Arab Emirates and the United States.
âBreeding new resilient crop varieties quickly, economically and with greater precision will be critical to ensure small-scale farmers can adapt to climate change,â said Enock Chikava, interim Director of Agricultural Development at the Bill & Melinda Gates Foundation. âThis initiative will contribute to a more promising and sustainable future for the hundreds of millions of Africans who depend on farming to support their families.â
Over the past 40 years, CGIAR Centers have built up the largest and most frequently accessed network of genebanks in the world. The network conserves and makes nearly three-quarters of a million crop accessions available to scientists and governments. CGIAR genebanks hold around 10% of the worldâs plant germplasm in trust for humanity, but account for about 94% of the germplasm distributed under the International Treaty on Plant Genetic Resources for Food and Agriculture, which ensures crop breeders globally have access to the fundamental building blocks of new varieties.
âThis research to develop climate-smart crop varieties, when scaled, is key to ensuring that those hardest hit by climate shocks have access to affordable staple foods,â said Jeffrey Rosichan, Director of the Crops of the Future Collaborative of the Foundation for Food & Agriculture Research (FFAR). âFurther, this initiative benefits US and world agriculture by increasing genetic diversity and providing tools for growers to more rapidly adapt to climate change.â
âWe will implement, for the first time, a scalable strategy to identify valuable variations hidden in our genebanks, and through breeding, deploy these to farmers who urgently need solutions to address the threat of climate change,â said Sarah Hearne, CIMMYT principal scientist and leader of the project.
Building on ten years of support to CIMMYT from the Mexican government, CGIAR Trust Fund contributors and the United Kingdomâs Biotechnology and Biological Sciences Research Council (BBSRC), the project combines the use of cutting-edge technologies and approaches, high-performance computing, GIS mapping, and new plant breeding methods, to identify and use accessions with high value for climate-adaptive breeding of varieties needed by farmers and consumers.
INTERVIEW OPPORTUNITIES:
Sarah Hearne â Principal Scientist, International Maize and Wheat Improvement Center (CIMMYT)
FOR MORE INFORMATION, OR TO ARRANGE INTERVIEWS, CONTACT THE MEDIA TEAM:
Marcia MacNeil, Head of Communications, CIMMYT. m.macneil@cgiar.org, +52 5558042004 ext. 2070.
Over the course of ten years, WHEAT worked with hundreds of research and development partners worldwide to release high-yielding, disease-resistant, nutritious and climate-resilient wheat varieties, and efficient, sustainable wheat-based cropping systems.
This final report from 2021 shares important research on staple cerealsâ role in global efforts towards food security, the number and distribution of wheat farms, the expected impact of climate change on wheat productivity, nitrogen-in-agriculture research, nutrition, and the most critical, immediate effects of COVID-19 on food systems, and more.
With its national partners, WHEAT released 70 new CGIAR-derived wheat varieties to farmers in 13 countries in 2021, and developed 18 innovations in the areas of genetics, biophysics, farm management, research and communication methods, or social sciences.
This international Womenâs Day, March 8, 2022, the International Maize and Wheat Improvement Center (CIMMYT) celebrates the essential role that women play in agriculture and food systems, and acknowledges that gender equality is essential to achieve a sustainable future. The burden of climate change impacts women disproportionately, even though we rely on them to drive change in climate adaptation, mitigation and solutions.
For example, in the last year, CIMMYT research found that educating women farming wheat in Bihar, India, increases the adoption of climate-smart agricultural practices, which, in turn, reduces greenhouse gas emissions, and boosts nitrogen productivity, eco-efficiency and yield. Additionally, in Mexico, a CIMMYT study found that women are less likely to default on agricultural credit than men, but seldom receive loans. Connecting women to financial capital to obtain agricultural inputs is an essential step in boosting their decision-making in food production.
Read more about our pathbreaking work in gender research in the collection of stories below!
Gender equality for climate-resilient, sustainable food systems
A farmer weeds a maize field in Pusa, Bihar state, India. (Photo: M. DeFreese/CIMMYT)
Gender-responsive and gender-intentional maize breeding
A new paper by CIMMYT researchers takes stock of lessons learnt on gender inclusivity and maize breeding in Africa. Scientists also assess knowledge gaps that need to be filled to effectively support gender-responsive and gender-intentional breeding and seed systems work.
Alice Nasiyimu stands in front of a drought-tolerant maize plot at her family farm in Bungoma County, in western Kenya. (Photo: Joshua Masinde/CIMMYT)
Towards gender-transformative research in the CGIAR
Gender scientists from ten CGIAR centers and key partner institutions came together in a hybrid workshop to integrate gender-transformative research and methodologies into the new CGIAR Initiatives. In this series of videos, GENNOVATE partners share their insights on this topic.
The International Maize and Wheat Improvement Center (CIMMYT) mourns the passing of our much respected and admired colleague, agriculture, forestry and global development leader, Barbara H. Wells.
Wells held the positions of Global Director of Genetic Innovation of CGIAR and Director General of the International Potato Center (CIP). She had over 30 years of experience in multiple areas of research and management of innovations in the agriculture and forestry sectors. Barbara also served at several senior executive positions in the private sector throughout her outstanding career.
âWe are deeply saddened by the news of Barbaraâs passing and send our heartfelt condolences to her family, friends and colleagues at our sister center CIP,â said CIMMYT Director General Bram Govaerts.
CIPâs projects and activities flourished under her leadership, opening new collaboration opportunities with local partners and fellow CGIAR centers, particularly with those based in the Americas.
In their partnership, CIMMYT and CIP have successfully collaborated in several areas of research and capacity building for the benefit of smallholder farmers throughout the region; including:
Building resilience through poverty- and food security-based safety nets, including links to productive programs;
Rural financial inclusion, including different types of savings, loans, and credit instruments, management of risk, and remittances;
New financial arrangements and governance structures in value chains;
Public-policy institutional mechanisms for dialogue on policymaking;
Successful R&D and extension projects funded by local governments at both national and state levels;
A regional approach to agricultural policies and role of sub-national governments and intermediate cities; and
Delivery and monitoring instruments, including use of ICT technology.
âWe want our colleagues and friends throughout the world to know that we will honor Barbaraâs legacy by redoubling our efforts for those who really mattered to her, the farmers,â Govaerts said.
Emerging in the last 120 years, science-based plant breeding begins by creating novel diversity from which useful new varieties can be identified or formed. The most common approach is making targeted crosses between parents with complementary, desirable traits. This is followed by selection among the resulting plants to obtain improved types that combine desired traits and performance. A less common approach is to expose plant tissues to chemicals or radiation that stimulate random mutations of the type that occur in nature, creating diversity and driving natural selection and evolution.
Determined by farmers and consumer markets, the target traits for plant breeding can include improved grain and fruit yield, resistance to major diseases and pests, better nutritional quality, ease of processing, and tolerance to environmental stresses such as drought, heat, acid soils, flooded fields and infertile soils. Most traits are genetically complex â that is, they are controlled by many genes and gene interactions â so breeders must intercross and select among hundreds of thousands of plants over generations to develop and choose the best.
Plant breeding over the last 100 years has fostered food and nutritional security for expanding populations, adapted crops to changing climates, and helped to alleviate poverty. Together with better farming practices, improved crop varieties can help to reduce environmental degradation and to mitigate climate change from agriculture.
Is plant breeding a modern technique?
Plant breeding began around 10,000 years ago, when humans undertook the domestication of ancestral food crop species. Over the ensuing millennia, farmers selected and re-sowed seed from the best grains, fruits or plants they harvested, genetically modifying the species for human use.
Modern, science-based plant breeding is a focused, systematic and swifter version of that process. It has been applied to all crops, among them maize, wheat, rice, potatoes, beans, cassava and horticulture crops, as well as to fruit trees, sugarcane, oil palm, cotton, farm animals and other species.
With modern breeding, specialists began collecting and preserving crop diversity, including farmer-selected heirloom varieties, improved varieties and the cropsâ undomesticated relatives. Today hundreds of thousands of unique samples of diverse crop types, in the form of seeds and cuttings, are meticulously preserved as living catalogs in dozens of publicly-administered âbanks.â
The International Maize and Wheat Improvement Center (CIMMYT) manages a germplasm bank containing more than 180,000 unique maize- and wheat-related seed samples, and the Svalbard Global Seed Vault on the Norwegian island of Spitsbergen preserves back-up copies of nearly a million collections from CIMMYT and other banks.
Through genetic analyses or growing seed samples, scientists comb such collections to find useful traits. Data and seed samples from publicly-funded initiatives of this type are shared among breeders and other researchers worldwide. The complete DNA sequences of several food crops, including rice, maize, and wheat, are now available and greatly assist scientists to identify novel, useful diversity.
Much crop breeding is international. From its own breeding programs, CIMMYT sends half a million seed packages each year to some 800 partners, including public research institutions and private companies in 100 countries, for breeding, genetic analyses and other research.
Early in the 20th century, plant breeders began to apply the discoveries of Gregor Mendel, a 19th-century mathematician and biologist, regarding genetic variation and heredity. They also began to take advantage of heterosis, commonly known as hybrid vigor, whereby progeny of crosses between genetically different lines will turn out stronger or more productive than their parents.
Modern statistical methods to analyze experimental data have helped breeders to understand differences in the performance of breeding offspring; particularly, how to distinguish genetic variation, which is heritable, from environmental influences on how parental traits are expressed in successive generations of plants.
Since the 1990s, geneticists and breeders have used molecular (DNA-based) markers. These are specific regions of the plantâs genome that are linked to a gene influencing a desired trait. Markers can also be used to obtain a DNA âfingerprintâ of a variety, to develop detailed genetic maps and to sequence crop plant genomes. Many applications of molecular markers are used in plant breeding to select progenies of breeding crosses featuring the greatest number of desired traits from their parents.
Plant breeders normally prefer to work with âeliteâ populations that have already undergone breeding and thus feature high concentrations of useful genes and fewer undesirable ones, but scientists also introduce non-elite diversity into breeding populations to boost their resilience and address threats such as new fungi or viruses that attack crops.
Transgenics are products of one genetic engineering technology, in which a gene from one species is inserted in another. A great advantage of the technology for crop breeding is that it introduces the desired gene alone, in contrast to conventional breeding crosses, where many undesired genes accompany the target gene and can reduce yield or other valuable traits. Transgenics have been used since the 1990s to implant traits such as pest resistance, herbicide tolerance, or improved nutritional value. Transgenic crop varieties are grown on more than 190 million hectares worldwide and have increased harvests, raised farmersâ income and reduced the use of pesticides. Complex regulatory requirements to manage their potential health or environmental risks, as well as consumer concerns about such risks and the fair sharing of benefits, make transgenic crop varieties difficult and expensive to deploy.
Genome editing or gene editing techniques allow precise modification of specific DNA sequences, making it possible to enhance, diminish or turn off the expression of genes and to convert them to more favorable versions. Gene editing is used primarily to produce non-transgenic plants like those that arise through natural mutations. The approach can be used to improve plant traits that are controlled by single or small numbers of genes, such as resistance to diseases and better grain quality or nutrition. Whether and how to regulate gene edited crops is still being defined in many countries.
The mobile seed shop of Victoria Seeds Company provides access to improved maize varieties for farmers in remote villages of Uganda. (Photo: Kipenz Films for CIMMYT)
Selected impacts of maize and wheat breeding
In the early 1990s, a CIMMYT methodology led to improved maize varieties that tolerate moderate drought conditions around flowering time in tropical, rainfed environments, besides featuring other valuable agronomic and resilience traits. By 2015, almost half the maize-producing area in 18 countries of sub-Saharan Africa â a region where the crop provides almost a third of human calories but where 65% of maize lands face at least occasional drought â was sown to varieties from this breeding research, in partnership with the International Institute of Tropical Agriculture (IITA). The estimated yearly benefits are as high as $1 billion.
Intensive breeding for resistance to Maize Lethal Necrosis (MLN), a viral disease that appeared in eastern Africa in 2011 and quickly spread to attack maize crops across the continent, allowed the release by 2017 of 18 MLN-resistant maize hybrids.
Improved wheat varieties developed using breeding lines from CIMMYT or the International Centre for Agricultural Research in the Dry Areas (ICARDA) cover more than 100 million hectares, nearly two-thirds of the area sown to improved wheat worldwide, with benefits in added grain that range from $2.8 to 3.8 billion each year.
Breeding for resistance to devastating crop diseases and pests has saved billions of dollars in crop losses and reduced the use of costly and potentially harmful pesticides. A 2004 study showed that investments since the early 1970s in breeding for resistance in wheat to the fungal disease leaf rust had provided benefits in added grain worth 5.36 billion 1990 US dollars. Global research to control wheat stem rust disease saves wheat farmers the equivalent of at least $1.12 billion each year.
Crosses of wheat with related crops (rye) or even wild grasses â the latter known as wide crosses â have greatly improved the hardiness and productivity of wheat. For example, an estimated one-fifth of the elite wheat breeding lines in CIMMYT international yield trials features genes from Aegilops tauschii, commonly known as âgoat grass,â that boost their resilience and provide other valuable traits to protect yield.
Biofortification â breeding to develop nutritionally enriched crops â has resulted in more than 60 maize and wheat varieties whose grain offers improved protein quality or enhanced levels of micro-nutrients such as zinc and provitamin A. Biofortified maize and wheat varieties have benefited smallholder farm families and consumers in more than 20 countries across sub-Saharan Africa, Asia, and Latin America. Consumption of provitamin-A-enhanced maize or sweet potato has been shown to reduce chronic vitamin A deficiencies in children in eastern and southern Africa. In India, farmers have grown a high-yielding sorghum variety with enhanced grain levels of iron and zinc since 2018 and use of iron-biofortified pearl millet has improved nutrition among vulnerable communities.
Innovations in measuring plant responses include remote sensing systems, such as multispectral and thermal cameras flown over breeding fields. In this image of the CIMMYT experimental station in ObregĂłn, Mexico, water-stressed plots are shown in green and red. (Photo: CIMMYT and the Instituto de Agricultura Sostenible)
Thefuture
Crop breeders have been laying the groundwork to pursue genomic selection. This approach takes advantage of low-cost, genome-wide molecular markers to analyze large populations and allow scientists to predict the value of particular breeding lines and crosses to speed gains, especially for improving genetically complex traits.
Speed breeding uses artificially-extended daylength, controlled temperatures, genomic selection, data science, artificial intelligence tools and advanced technology for recording plant information â also called phenotyping â to make breeding faster and more efficient. A CIMMYT speed breeding facility for wheat features a screenhouse with specialized lighting, controlled temperatures and other special fixings that will allow four crop cycles â or generations â to be grown per year, in place of only two cycles with normal field trials. Speed breeding facilities will accelerate the development of productive and robust varieties by crop research programs worldwide.
Data analysis and management. Growing and evaluating hundreds of thousands of plants in diverse trials across multiple sites each season generates enormous volumes of data that breeders must examine, integrate, and co-analyze to inform decisions, especially about which lines to cross and which populations to discard or move forward. New informatics tools such as the Enterprise Breeding System will help scientists to manage, analyze and apply big data from genomics, field and lab studies.
Following the leaders. Driven by competition and the quest for profits, private companies that market seed and other farm products are generally on the cutting edge of breeding innovations. The CGIARâs Excellence in Breeding (EiB) initiative is helping crop breeding programs that serve farmers in low- and middle-income countries to adopt appropriate best practices from private companies, including molecular marker-based approaches, strategic mechanization, digitization and use of big data to drive decision making. Modern plant breeding begins by ensuring that the new varieties produced are in line with what farmers and consumers want and need.
New improved maize varieties may fall short in meeting the needs of women and the poorest of farmers â a concern that remains a focus of the International Maize and Wheat Improvement Center (CIMMYT) and the wider CGIAR.
Lower than expected adoption rates for some new maize varieties suggest that innovative strategies in breeding and seed delivery are likely needed. There is broad recognition of the need to get new germplasm from the CGIAR and its partners into the fields of more farmers in less time.
CIMMYT research on markets and social inclusion focuses on understanding two related dynamics: the unique preferences, needs and circumstances faced by women and the poorest farmers, and the implications these carry for how breeding programs and seed companies design and market new varieties.
Taking stock of knowledge and gaps in gender and maize breeding
Decades of research on maize preferences have sought to understand if and how menâs and womenâs preferences differ. However, existing data provides unclear guidance to maize breeders on gender-relevant traits to prioritize in product profile design. The evidence suggests a lack of meaningful differences in what men and women are looking for in maizeÂÂâyield, drought tolerance and early maturityâare high priorities almost across the board.
One reason for the similarity in preferences among women and men may relate to how we evaluate them, the authors argue. Preference studies that focus on evaluation of varietiesâ agronomic and productivity-related traits may overlook critical components of farmersâ variety assessment and seed choice, including their household and farming context. Ultimately, they say, we need to explore new approaches to evaluating farmer demand for seed, considering new questions instead of continuing to look for gender-based differences in preferences.
A first step in that direction is to figure out how demand for maize seed differs among farmers according to their needs, priorities and resource limitations. Gender is definitely a part of that equation, but thereâs much more to think about, like how maize fits into household food security and livelihoods, decision-making dynamics around maize production, and seed accessibility. New tools will be needed for understanding those and how decision-making around seed happens in real-world contexts.
Understanding how farmers make decisions on seed choice
The authors offer several practical suggestions for maize breeders and other researchers in this space:
First, explore tools that allow farmers to evaluate varieties in their household context. Large-scale farmer-managed on-farm trials have gained attention in the CGIAR as tools for more accurate assessment of farmer preferences. These approaches have several added advantages. They enable evaluation of variety performance under realistic management conditionsâincluding under management practices used disproportionately by women, such as intercropping, which is typically excluded from larger researcher-managed trials. These approaches also enable farmer evaluation of maize varieties not only in terms of in-field performance and yield at harvest stage, but in terms of grain quality after harvest. This is particularly important for social inclusion, given womenâs disproportionate attention to traits related to processing and consumption.
Second, move beyond gender-based preferences in evaluating seed demand. Gendered preferences matter, but they may not be the sole factor that determines a farmerâs choice of seed. We need to understand market segments for seed in relation to farmersâ aspirations, risk perceptions and tolerance, livelihood priorities, and household context. This also means exploring the intrahousehold gender dynamics of maize farming and seed choice to understand womenâs roles in decision-making in maize production, processing, and consumption.
Finally, consider questions related to maize seed systems more broadly. Are maize seed systems capable of delivering gender-responsive and gender-intentional varieties to women and men? What are the barriers to wider uptake of new varieties aside from variety suitability? Innovative marketing and delivery mechanisms may be critical to realizing gains from more gender-intentional breeding.
With the transition to the One CGIAR, sharing tools and lessons learned across crops will be increasingly important. Researchers in the CGIAR community have developed new tools for gender-responsive and gender-intentional breeding. This includes through the Gender and Breeding Initiative, which has published the G+ tools to support gendered market segmentation and gender-intentional product profile development.
While learning from one anotherâs experiences will prove essential during the transition, recognizing that the gender dynamics of maize production may be very different from sweet potato production will also be key. Here, the new Market Intelligence & Product Profiles initiative and SeEdQUAL initiative on seed systems will both create new spaces for exploring these issues across crops.
Sieg Snapp is the director of the Sustainable Agrifood Systems program at CIMMYT, which brings together global agricultural economics, systems analysis on agrifood innovations and agricultural systems for development in Africa, Asia and Latin America.
As a Professor of Soils and Cropping Systems Ecology at Michigan State University and Associate Director of the Center for Global Change and Earth Observations, she led research on sustainable farming, particularly for cereal-based, rainfed systems in Africa and North America.
Snapp first partnered with CIMMYT in 1993, when she developed the “mother and baby” trial design. This go-to tool for participatory research has developed farmer-approved technologies in 30 countries.
Snapp has partnered with local and international scientists to tackle sustainable development goals, improve livelihoods and farm sustainably. Her two hundred publications and text books address co-learning, ecological intensification and open data to generate relevant science.
A farmer harvests wheat in one of CIMMYT’s research plots in Ethiopia. (Photo: P. Lowe/CIMMYT)
Five international wheat research teams have been awarded grants for their proposals to boost climate resilience in wheat through discovery and development of new breeding technologies, screening tools and novel traits.
Wheat is one of the worldâs most important staple crops, accounting for about 20% of all human calories and protein and is increasingly threatened by the impacts of climate change. Experts around the world are working on ways to strengthen the crop in the face of increasing heat and drought conditions.
The proposals were submitted in response to a call by the Heat and Drought Wheat Improvement Consortium (HeDWIC), led by the International Maize and Wheat Improvement Center (CIMMYT) and global partners, made in 2021.
The grants were made possible by co-funding from the Foundation for Food & Agriculture Research (FFAR) and in-kind contributions from awardees as part of a project which brings together the latest research from scientists across the globe to deliver climate resilient wheat to farmers as quickly as possible.
Cutting-edge wheat research
Owen Atkin, from the Centre for Entrepreneurial Agri-Technology at the Australian National University, leads the awarded project âDiscovering thermally stable wheat through exploration of leaf respiration in combination with photosystem II capacity and heat tolerance.â
âThe ratio of dark respiration to light and CO2 saturated photosynthesis is a clear indicator of the respiratory efficiency of a plant,â Atkin said. âWe will measure and couple this indicator of respiratory efficiency to the leaf hyperspectral signature of field grown wheat exposed to heat and drought. The outcome could be a powerful tool which is capable of screening for wheat lines that are more productive when challenged with drought and heatwave.â
Hannah M. Schneider, of Wageningen University & Research, leads the awarded project examining the use of a novel root trait called Multiseriate Cortical Sclerenchyma to increase drought-tolerance in wheat.
âDrought is a primary limitation to global crop production worldwide. The presence of small outer cortical cells with thick, lignified cell walls (MCS: Multiseriate Cortical Sclerenchyma) is a novel root trait that has utility in drought environments,â Schneider said. âThe overall objective of this project is to evaluate and develop this trait as a tool to improve drought resistance in wheat and in other crops.â
An improved wheat variety grows in the field in Islamabad, Pakistan. (Photo: A. Yaqub/CIMMYT)
John Foulkes, of the University of Nottingham, leads an awarded project titled âIdentifying spike hormone traits and molecular markers for improved heat and drought tolerance in wheat.â
âThe project aims to boost climate-resilience of grain set in wheat by identifying hormone signals to the spike that buffer grain set against extreme weather, with a focus on cytokinin, ABA and ethylene responses,â Foulkes said. âThis will provide novel phenotyping screens and germplasm to breeders, and lay the ground-work for genetic analysis and marker development.â
Erik Murchie, from the University of Nottingham, leads an awarded project to explore new ways of determining genetic variation in heat-induced growth inhibition in wheat.
âHigh temperature events as part of climate change increasingly limit crop growth and yield by disrupting metabolic and developmental processes. This project will develop rapid methods for screening growth and physiological processes during heat waves, generating new genetic resources for wheat,â Murchie said.
Eric Ober of the National Institute of Agricultural Botany in the UK, leads the awarded project âTargeted selection for thermotolerant isoforms of starch synthase.â
âWheat remains a predominant source of calories and is fundamental to regional food security around the world. It is urgent that breeders are equipped to produce new varieties with increased tolerance to heat and drought, two stresses that commonly occur together, limiting grain production. The formation and filling of grain depends on the synthesis of starch, but a key enzyme in the pathway, starch synthase, is particularly sensitive to temperatures over 25°C. However, there exist forms of this enzyme that exhibit greater thermotolerance than that found in most current wheat varieties,â Ober said. âThis project aims to develop a simple assay to screen diverse germplasm for sources of more heat-resistant forms of starch synthase that could be bred into new wheat varieties in the future.â
Breakthroughs from these projects are expected to benefit other crops, not just wheat. Other benefits of the projects include closer interaction between scientists and breeders and capacity building of younger scientists.
Genomic selection identifies individual plants based on the information from molecular markers, DNA signposts for genes of interest, that are distributed densely throughout the wheat genome. For wheat blast, the results can help predict which wheat lines hold promise as providers of blast resistance for future crosses and those that can be advanced to the next generation after selection.
In this study, scientists from the International Maize and Wheat Improvement Center (CIMMYT) and partners evaluated genomic selection by combining genotypic data with extensive and precise field data on wheat blast responses for three sets of genetically diverse wheat lines and varieties, more than 700 in all, grown by partners at locations in Bangladesh and Bolivia over several crop cycles.
The study also compared the use of a small number of molecular markers linked to the 2NS translocation, a chromosome segment from the grass species Aegilops ventricosa that was introduced into wheat in the 1980s and is a strong and stable source of blast resistance, with predictions using thousands of genome-wide markers. The outcome confirms that, in environments where wheat blast resistance is determined by the 2NS translocation, genotyping using one-to-few markers tagging the translocation is enough to predict the blast response of wheat lines.
Finally, the authors found that selection based on a few wheat blast-associated molecular markers retained 89% of lines that were also selected using field performance data, and discarded 92% of those that were discarded based on field performance data. Thus, both marker-assisted selection and genomic selection offer viable alternatives to the slower and more expensive field screening of many thousands of wheat lines in hot-spot locations for the disease, particularly at early stages of breeding, and can speed the development of blast-resistant wheat varieties.
The research was conducted by scientists from the International Maize and Wheat Improvement Center (CIMMYT), the Bangladesh Wheat and Maize Research Institute (BWMRI), the Instituto Nacional de InnovaciĂłn Agropecuaria y Forestal (INIAF) of Bolivia, the Borlaug Institute for South Asia (BISA) and the Indian Council of Agricultural Research (ICAR) in India, the Swedish University of Agricultural Sciences (Alnarp), and Kansas State University in the USA. Funding for the study was provided by the Bill & Melinda Gates Foundation, the Foreign and Commonwealth Development Office of the United Kingdom, the U.S. Agency for International Development (USAID), the CGIAR Research Program on Wheat (WHEAT), the Indian Council of Agricultural Research (ICAR), the Swedish Research Council, and the Australian Centre for International Agricultural Research (ACIAR).
Cover photo: A researcher from Bangladesh shows blast infected wheat spikes and explains how the disease directly attacks the grain. (Photo: Chris Knight/Cornell University)
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.
âBreeders are usually optimistic, overlooking many climate change factors when selecting,â said Matthew Reynolds, wheat physiologist at the International Maize and Wheat Improvement Center (CIMMYT) and co-author of the publication. âOur 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.â
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.
âTo 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,â Xiong said.
Xiong and his colleagues analyzed âcrossover interactionsâ â changes in the relative rankings of pairs of wheat lines â 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 linesâ 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.
âWe found that warmer and more erratic climates since the 1980s have increased ranking changes in global wheat breeding by as much as 15 percent,â Xiong said. âThis has made it harder for breeders to identify superior, broadly adapted lines and even led to scientists discarding potentially useful lines.â
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 wheatâs adaptation to current, warmer climates, while opening opportunities for larger and faster genetic gains in the future, according to the study.
âAmong other things, our findings argue for more targeted wheat breeding and testing to address rapidly shifting and unpredictable farming conditions,â Reynolds added.
Like many development research and funding organizations, the Australian Centre for International Agricultural Research (ACIAR) is emphasizing a renewed commitment to a nutrition-sensitive approach to agricultural development projects.
In the past decade, awareness has grown about the importance of diets that are rich in vitamins and minerals, and the need to combat micronutrient malnutrition which can lead to irreversible health outcomes impacting entire economies and perpetuating a tragic cycle of poverty and economic stagnation.
Lack of vitamins and minerals, often called âhidden hunger,â is not confined to lower-income food-insecure countries. In richer countries we clearly see a transition towards energy-rich, micronutrient-poor diets. In fact, populations throughout the world are eating more processed foods for reasons of convenience and price. To hit our global hunger and health targets we need to invest in nutrition-sensitive agricultural research and production as well as promoting affordable diets with varied and appealing nutrient-rich foods.
Alongside hunger, we have a pandemic of diet-related diseases that is partly caused by the over-consumption of energy-rich junk diets. This is because modern food formulations are often shaped towards addictive and unhealthy products. We see this in rising levels of obesity and diabetes, some cancers, heart diseases and chronic lung conditions.
Investing in agri-food research and improving nutrition will be much cheaper than treating these diet-related non-communicable diseases. Besides being healthier, many people will be much happier and able to live more productive lives.
Yet, the picture is bigger than micronutrient malnutrition. Even if new investments in research enable us to increase the production and delivery of fruits, vegetables and other nutrient-rich foods such as legumes and nuts, we will not have cracked the whole problem of food security, nutrition and health.
Besides âhidden hunger,â many hundreds of millions of people worldwide are hungry because they still lack the basic availability of food to live and work.
Enter cereals. Wheat, maize and rice have been the major sources of dietary energy in the form of carbohydrates in virtually all societies and for thousands of years: recent research in the Middle East suggests that the original âpaleoâ diet was not just the result of hunting and gathering, but included cereals in bread and beer!
There are three reasons why cereals are essential to feeding the world:
First, nutritionists and medics tell us that cereals not only provide macronutrients â carbohydrates, proteins and fats â and micronutrients â vitamins and minerals. We now know that cereals are important sources of bioactive food components that are not usually classed as nutrients, but are essential to health all the same. These are compounds like carotenoids, flavonoids, phytosterols, glucosinolates and polyphenols, which are found naturally in various plant foods and have beneficial antioxidant, anticarcinogenic, anti-inflammatory and antimicrobial properties, likely to be important in mitigating and/or combating disease.
Second, whole-grain foods, especially wheat, are also a major source of dietary fibre, which is essential for efficient digestion and metabolism. Fibre from cereals also nourishes the human gut flora whose products such as short-chain fatty acids have many health benefits including combatting some cancers. Eating such carbohydrates also helps us recognise that we have eaten sufficiently, so that we know when âenough is enough.â
Third, cereal foods are relatively cheap to produce and to buy, and also easy to transport and preserve. Hence, supplies are relatively stable, and good nutrition from cereals is likely to remain accessible to less affluent people.
But all is not well with cereals these days. Cereals are under siege from climate change-related heat and drought, and new and more virulent forms of plant diseases, which threaten our agriculture and natural resources. There remains much research to undertake in this era of rapidly changing climatic conditions, and of economic and political stresses.
Here are a few strategies for agri-food research and its supporters:
We can further increase the nutritional content of cereal foods through biofortification during plant breeding.
We can produce disease- and heat-resilient varieties of grains that are efficient in the use of water and fertilizer, and whose production is not labor-intensive.
By working with communities, we can adapt new production technologies to local conditions, especially where women are the farmers.
We can enhance the quality of cereal foods through nutrient fortification during milling, and by better processing methods and food formulation.
Experts in all agri-food disciplines can work together to inform and ânudgeâ consumers to make healthy food purchasing decisions.
Cereals matter, but in an age of misinformation, we still have to be cautious: Some people are susceptible to certain components of cereals such as gluten. People who are medically diagnosed with cereal intolerances must shape their diets accordingly and get their carbohydrates and bioactive food components from other sources.
So, we cannot live on bread alone: We should aim for diets which are rich in diverse foods.
Such diets include fruits and vegetables that must be accessible to people in different regions, particularly to the most vulnerable, and that provide different macronutrients, micronutrients and essential bioactive components. For most of us, the health-promoting content of cereals means that they must remain a major part of the global diet.
Nigel Poole is Emeritus Professor of International Development at SOAS University of London and Consultant at the International Maize and Wheat Improvement Center (CIMMYT).
Rajiv Sharma is Senior Scientist at the International Maize and Wheat Improvement Center (CIMMYT).
Alison Bentley is the Director of the Global Wheat Program at the International Maize and Wheat Improvement Center (CIMMYT).
In an op-ed on Newsweek, CIMMYT director general Bram Govaerts wrote argues the best protection is actually reducing food system risks by building food system resilience against shocks. He highlighted how previous investments in agricultural research and development generated evidence-based strategies that mitigate global food price crisis.
Grafting wheat shoot to oat root gives the plant tolerance to a disease called âTake-all,â 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 â representing their earliest embryonic stages â 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.
âWeâve 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,â said Julian Hibberd in the University of Cambridgeâs 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 â 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. âFrom 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.â
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 â from where it was seen to move up the plant and across the graft junction.
âI read back over decades of research papers on grafting and everybody said that it couldnât be done in monocots. I was stubborn enough to keep going â for years â until I proved them wrong,â said Greg Reeves, a Gates Cambridge Scholar in the University of Cambridge Department of Plant Sciences, and first author of the paper.
âItâs an urgent challenge to make important food crops resistant to the diseases that are destroying them,â Reeves explained. âOur 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.â
The worldâs banana industry is based on a single variety, called the Cavendish banana â 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 â including apples and cherries, and high-value annual crops including tomatoes and cucumbers â 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.
âPanama disease is a huge problem threatening bananas across the world. Itâs fantastic that the University of Cambridge has the opportunity to play a role in saving such an important food crop,â 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 worldâs 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 âCambridge clusterâ, in which more than 5,300 knowledge-intensive firms employ more than 67,000 people and generate ÂŁ18 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)
Several recent studies document the long-term health and economic benefits from the âGreen Revolutionâ â the widespread adoption of high-yielding staple crop varieties during the last half of the 20th century â and argue for continued investment in the development and use of such varieties.
âOur estimates provide compelling evidence that the health benefits of broad-based increases in agricultural productivity should not be overlooked,â the authors state. âFrom a policy perspective, government subsidies for inputs leading to a green revolution as well as investments in extension and R&D programs seem to be important.â
Norman Borlaug (fourth from right) shows a plot of Sonora-64 wheat â one of the semi-dwarf, high-yield, disease-resistant varieties that was key to the Green Revolution â to a group of young international trainees at CIMMYT’s experimental station in Ciudad Obregon, Sonora state, Mexico. (Photo: CIMMYT)
The COVID-19 pandemic exposed the fragility of the global food system and the need to transform it, increasing its environmental and economic resilience to withstand future threats, and underpinning healthier diets. The studies suggest that improved versions of cereal crops such as rice, wheat, and maize can play a key role.
âOur work speaks to the importance of supporting innovation and technology adoption in agriculture as a means of fostering economic development, improved health, and poverty reduction, said author Jan von der Goltz. âIt also suggests that it is reasonable to view with some alarm the steady decline in funding for cereal crop improvement over the last few decades in sub-Saharan Africa, the continent with least diffusion of modern varieties.â
Likewise, a study co-authored by Prashant Bharadwaj of the University of California, San Diego, concluded that farmer adoption of high-yielding crop varieties (HYVs) in India reduced infant mortality dramatically across the country. Between 1960 and 2000, infant deaths dropped from 163.8 to 66.6 per 1,000 live births, and this occurred during the decades of Indiaâs wheat productivity leap from 0.86 to 2.79 tons per hectare, as a result of HYV adoption and improved farming practices.
âWhat both of these papers do is to carefully establish a causal estimate of how HYVs affect infant mortality, by only comparing children born in the same location at different points in time, when HYV use was different, and by checking that mortality before arrival of HYVs was trending similarly in places that would receive different amount of HYVs,â Bharadwaj said.
âIn the absence of a randomized control trial, these econometric techniques produce the best causal estimate of a phenomenon as important as the spread of HYVs during and after the Green Revolution,â he added. These thoughts were echoed by University of California San Diego professor Gordon McCord, a co-author of the global study.
Recent studies indicate that the Green Revolution also had long-term economic impacts, which also affected health outcomes.
In a 2021 update to the 2018 paper âTwo Blades of Grass: The Impact of the Green Revolution,â Douglas Gollin, Professor of Development Economics at Oxford University and co-authors found that, in 90 countries where high-yielding varieties were adopted between 1965 and 2010, food crop yields increased by 44% and that, had this adoption not occurred, GDP per capita in the developing world could be half of what it is today.
Even a 10-year delay of the Green Revolution would, in 2010, have cost 17% of GDP per capita in the developing world, with a cumulative GDP loss of $83 trillion, equivalent to one year of current global GDP.
These GDP and health impacts were boosted by a related reduction in population growth. By observing causal inference at country, regional and developing world levels, and using a novel long-term impact assessment method, the study authors detected a trend: as living standards improved for rural families, they generally wanted to invest more in their children and have fewer.
âOur estimates suggest that the world would have contained more than 200 million additional people in 2010, if the onset of the Green Revolution had been delayed for ten years,â Gollin and his co-authors stated. This lower population growth seems to have increased the relative size of the working age population, which furthered GDP growth.
Ethiopian farmers give feedback to CGIAR researchers about durum wheat varieties. (Photo: C.Fadda/Bioversity International) (CC BY-NC-ND 2.0)
A long-term investment in system transformation
It takes time from the point of an intervention to when broad health impacts can be observed in the population, the authors note. For example, although the development of modern high-yielding varieties began in the 1950s and 60s, the rate of adoption did not speed up until the 1980s, 1990s, and even into the 2000s, with evidence from sub-Saharan Africa showing that variety adoption has increased by as much in the 2000s as in the four preceding decades.
In addition, any nutrition and food security strategy which aims to reach the second Sustainable Development Goal of feeding 9 billion by 2050 must incorporate wider system transformation solutions, such as zero-emissions agriculture, affordable, diverse diets and increased land conservation.
As Gollin explained, âThe Green Revolution taught us that we need to approach productivity increases, especially in staple crop yields, differently. The challenge now is more complex: we need to get the same productivity increases, with fewer inputs and resources, more environmental awareness, and in larger quantities for more people.â
In part, this means increasing productivity on existing agricultural land with positive environmental and social impacts, according to Bram Govaerts, director general of the International Maize and Wheat Improvement Center (CIMMYT).
âBreeding and sharing more productive, hardy crop varieties is as important as ever,â Govaerts said, âbut also engaging farmers â in our case, smallholders â in shared research and innovation efforts to bridge yield gaps, build climate-resilient farming systems, and open access to better nutrition and market opportunities.â
Cover photo: Children eat lunch at a mobile crĂšche outside Delhi, India. (Photo: Atul Loke/ODI) (CC BY-NC 2.0)
