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funder_partner: Kansas State University

CropSustaiN BNI Wheat Mission

The Novo Nordisk Foundation and CIMMYT have launched the 4-year CropSustaiN initiative to determine the global potential of wheat that is significantly better at using nitrogen, thanks to Biological Nitrification Inhibition (BNI)—and to accelerate breeding and farmer access to BNI wheat varieties.

With a budget of US$ 21 million, CropSustaiN addresses the pressing challenges of nitrogen pollution and inefficient fertilizer use, which contribute to greenhouse gas (GHG) emissions and ecological degradation. Currently, no other seed or agronomic practice-based solution matches BNI crops’ mitigation impact potential. Growing BNI crops can complement other climate mitigation measures.

The challenge

Agriculture is at the heart of both food and nutrition security and environmental sustainability. The sector contributes ca. 10-12% of global GHG emissions, including 80% of the highly potent nitrous oxide (N2O) emissions. Fertilizer use contributes to such N losses, because plants take up about 50%, the remainder being lost. Wheat is the world’s largest ‘crop’ consumer of nitrogen-based fertilizer—a relatively nitrogen-inefficient cereal—at the same time providing affordable calories to billions of resource-poor people and ca. 20% of globally consumed protein. CropSustaiN targets this nexus of productivity and planetary boundary impact by verifying and thus de-risking the needed breeding, agronomic, and social innovations.

A solution: BNI-wheat

BNI is a natural ability of certain plant species to release metabolites from their roots into the soil. They influence the nitrogen-transforming activity of nitrifying bacteria, slowing down the conversion of ammonium to nitrate in the soil. This preserves soil ammonium levels for a longer time, providing plants with a more sustained source of available nitrogen and making them more nitrogen-use efficient (nitrogen plant use efficiency). As a result, BNI helps reduce the release of N2O gas emissions and nitrate leaching to the surrounding ecosystem.

A research breakthrough in 2021, led by the Japan International Research Center of Agricultural Sciences (JIRCAS) in collaboration with CIMMYT, demonstrated that the BNI trait can be transferred from a wheat wild relative to a modern wheat variety by conventional breeding. BNI wheat can be made available to farmers worldwide.

Growing BNI wheat could reduce nitrogen fertilizer usage by 15-20%, depending on regional farming conditions, without sacrificing yield or quality.

 

Incorporating BNI into additional crops would reduce usage further. Farmers can get the same yield with less external inputs.

Other BNI-crops

CropSustaiN will work on spring and winter wheats. Rice, maize, barley, and sorghum also have BNI potential. CropSustaiN will build the knowledge base and share with scientists working on other crops and agronomic approaches.

Objectives and outcomes

This high risk, high reward mission aims to:

  • Verify the global, on-farm potential of BNI-wheat through field trial research and breeding.
  • Build the partnerships and pathways to meet farmer demand for BNI-wheat seeds.
  • Work with stakeholders on policy change that enables BNI crops production and markets

Success will be measured by determining nitrogen pollution reduction levels under different soil nitrogen environments and management conditions on research stations, documenting crop performance and safety, breeding for BNI spring and winter wheats for a wide range of geographies, and gauging farmer needs, interest, and future demand.

Wheat spikes against the sky at CIMMYT’s El Batán, Mexico headquarters. (Photo: H. Hernandez Lira/CIMMYT)

A collaborative effort

CIMMYT is the lead implementer of Novo Nordisk Foundation’s mission funding. CropSustaiN’s interdisciplinary, intersectoral, systems approach relies on building partnerships and knowledge-sharing within and outside this research initiative. 45+ partners are engaged in CropSustaiN.

The potential GHG emissions reduction from deploying BNI-wheat is estimated to be 0.016-0.19 gigatonnes of CO2-equivalent emissions per year, reducing 0.4-6% of total global N2O emissions annually, plus a lowering of nitrate pollution.

Impact on climate change mitigation and Nationally Determined Contributions (NDCs)

The assumption is that BNI wheat is grown in all major wheat-growing areas and that farmers will practice a behavioral shift towards lower fertilizer use and higher fertilizer use efficiency. That could lead to ca. a reduction of 17 megatons per year globally. This can help nations achieve their NDCs under the Paris Agreement.

International public goods, governance, and management

CIMMYT and the Foundation are committed to open access and the dissemination of seeds, research data, and results as international public goods. The governance and management model reinforces a commitment to equitable global access to CropSustaiN outputs, emphasized in partnership agreements and management of intellectual property.

Invitation to join the mission

The CropSustaiN initiative is a bold step towards agricultural transformation. You are invited to become a partner. You can contribute to the mission with advice, by sharing methods, research data and results, or becoming a co-founder.

Please contact CropSustaiN Mission Director, Victor Kommerell, at v.kommerell@cgiar.org or Novo Nordisk Foundation’s Senior Scientific Manager, Jeremy A. Daniel, at jad@novo.dk.

Additional reference material

  1. BNI International Consortium (Japan International Research Center for Agricultural Sciences, JIRCAS)
  2. Nitrification inhibitors: biological and synthetic (German Environment Agency, Umweltbundesamt)
  3. CropSustaiN: new innovative crops to reduce the nitrogen footprint form agriculture
  4. Annual Technical Report 2024. CropSustaiN: A new paradigm to reduce the nitrogen footprint from agriculture
  5. BNI-Wheat Future: towards reducing global nitrogen use in wheat
  6. CIMMYT Publications Repository

Examining how insects spread toxic fungi

Maize grain heavily damaged by the larger grain borer and maize weevil. (Photo: Jessica González/CIMMYT)

According to the World Health Organization (WHO), 10% of the global population suffers from food poisoning each year. Aflatoxins, the main contributor to food poisoning around the world, contaminate cereals and nuts and humans, especially vulnerable groups like the young, elderly, or immune-compromised, and animals are susceptible to their toxic and potentially carcinogenic effects.

Fungi contamination occurs all along the production cycle, during and after harvest, so the mitigation of the mycotoxins challenge requires the use of an integrated approach, including the selection of farmer-preferred tolerant varieties, implementing good agricultural practices such as crop rotation or nitrogen management, reducing crop stress, managing pests and diseases, biological control of mycotoxigenic strains, and good post-harvest practices.

Monitoring of mycotoxins in food crops is important to identify places and sources of infestations as well as implementing effective agricultural practices and other corrective measures that can prevent outbreaks.

A bug problem

Insects can directly or indirectly contribute to the spread of fungi and the subsequent production of mycotoxins. Many insects associated with maize plants before and after harvest act as a vector by carrying fungal spores from one location to another.

International collaboration is key to managing the risks associated with the spread of invasive pests and preventing crop damage caused by the newly introduced pests. CIMMYT, through CGIAR’s Plant Health initiative, partners with the Center for Grain and Animal Health Research of the US Department of Agriculture (USDA) and Kansas State University are investigating the microbes associated with the maize weevil and the larger grain borer.

The experiment consisted of trapping insects in three different habitats, a prairie near CIMMYT facilities in El Batán, Texcoco, Mexico, a maize field, and a maize store at CIMMYT’s experimental station at El Batán, using Lindgren funnel traps and pheromones lures.

Hanging of the Lindgren funnel traps in a prairie near El Bátan, Texcoco, Mexico. (Photo: Jessica González/CIMMYT)

Preliminary results of this study were presented by Hannah Quellhorst from the Department of Entomology at Kansas State University during an online seminar hosted by CIMMYT.

The collected insect samples were cultured in agar to identify the microbial community associated with them. Two invasive pests, the larger grain bore and the maize weevil, a potent carcinogenic mycotoxin was identified and associated with the larger grain borer and the maize weevil.

The larger grain borer is an invasive pest, which can cause extensive damage and even bore through packaging materials, including plastics. It is native to Mexico and Central America but was introduced in Africa and has spread to tropical and subtropical regions around the world. Together with the maize weevil, post-harvest losses of up to 60% have been recorded in Mexico from these pests.

“With climate change and global warming, there are risks of these pests shifting their habitats to areas where they are not currently present like sub-Saharan Africa and North Africa,” said Quelhorst. “However, the monitoring of the movement of these pests at an international level is lacking and the microbial communities moving with these post-harvest insects are not well investigated.”

Zambia officials promote sustainable maize cropping practices for small-scale farmers

For the first time in Zambia, a special Ministry of Agriculture committee has endorsed innovative sustainable intensification practices to diversify maize-based farming systems and boost the food and nutritional security of millions of small farm households, while enriching depleted soils.

Zambia’s recently formed “National Advisory Committee for the Approval/Validation of Candidate Technologies or Agronomic Practices” approved in September the release to farmers of three new systems for better yields and soil maintenance: growing maize between “hedge-rows” of legume trees; or in rows side-by-side with grain legumes as strip crops; or on permanent, raised soil beds or ridges.

Legume trees and grain legumes enhance soil nitrogen and organic matter content, and legume grains themselves are a valuable, alternative food, rich in protein for rural households. Raised soil beds and ridges can keep soils oxygenated and productive when heavy rainfall floods the fields, as can often occur in northern and northwestern Zambia.

All three systems can be bundled with conservation agriculture approaches, which are based on the principles of minimum soil disturbance, keeping crop residues on the soil, and growing a more diverse selection of crops.

The improved maize cropping methods are a research outcome of the Sustainable Intensification of Smallholder Farming Systems in Zambia (SIFAZ) project, a partnership involving the Food and Agriculture Organization (FAO) of the United Nations, Zambia’s Ministry of Agriculture (MoA), and the International Maize and Wheat Improvement Centre (CIMMYT), with funding from the European Union (EU) and building in part on other results in Africa, including the Feed the Future-Africa Research in Sustainable Development for the Next Generation (Africa RISING) initiative.

“The official clearing of these transformative cropping technologies is a huge milestone for the project and for Zambia’s resource-poor farmers,” said Christian Thierfelder, CIMMYT principal cropping systems agronomist based in southern Africa who, as part of SIFAZ, is testing and disseminating maize cropping practices that boost harvests, enrich soils, and capture and conserve moisture. “We’re working closely with Zambia’s MoA and the FAO, planning research trials, demonstrations and promotion to reach 20,000 farmers as a first step.”

An essential crop

Maize is the number-one food staple in sub-Saharan Africa, sown by some 300 million smallholder farmers using seasonal rains. A leading crop as well for Zambia’s small-scale, subsistence, and often impoverished farmers, maize grows poorly in extreme heat, infertile soils, and extended dry weather. Failed maize crops can bring hunger to smallholders and their families, for whom risks are high and formal safety nets are non-existent.

The EU recently announced that it will provide an additional EUR 20 million in funding for SIFAZ, now three years old and operating in five provinces and 27 districts of Zambia.

The cropping practices submitted to the National Advisory Committee by Thierfelder and his colleagues conform to a sustainable intensification assessment framework developed by the Feed the Future Innovation Lab for Collaborative Research on Sustainable Intensification of the US Agency for International Development (USAID) and Kansas State University.

“The framework provides a set of indicators for evaluating technologies according to their effects on productivity, economics, the environment, and social and human conditions — domains considered essential for sustainable agriculture systems,” Thierfelder explained. “The framework is well suited for smallholder farm settings, where agriculture is linked to development goals such as alleviating poverty, avoiding land degradation, increasing food and nutrition security, and supporting women’s empowerment.”

Cover photo: Jane Miti, a Zambia extension methodology officer, is testing intercropped strips of maize and soybean at Nyanje, Sinda District, to improve her soils and yields. (Photo: Christian Thierfelder/CIMMYT)

New publications: Genome-wide breeding to curtail wheat blast

A recent publication in the journal Frontiers of Plant Science provides results of the first-ever study to test genomic selection in breeding for resistance to wheat blast, a deadly disease caused by the fungus Magnaporthe oryzae that is spreading from its origin in Brazil to threaten wheat crops in South Asia and sub-Saharan Africa.

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.

Read the full study:
Genomic Selection for Wheat Blast in a Diversity Panel, Breeding Panel and Full-Sibs Panel

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 Innovación 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)

Scientists bridge theory and practice to boost climate resilience in wheat

With the past decade identified as the warmest on record and global temperatures predicted to rise by as much as 2 degrees Celsius over preindustrial levels by 2050, the world’s staple food crops are increasingly under threat.

A new review published this month in the Journal of Experimental Botany describes how researchers from the International Maize and Wheat Improvement Center (CIMMYT) and collaborators are boosting climate resilience in wheat using powerful remote sensing tools, genomics and big data analysis. Scientists are combining multiple approaches to explore untapped diversity among wheat genetic resources and help select better parents and progeny in breeding.

The review — authored by a team of 25 scientists from CIMMYT, Henan Agricultural University, the University of Adelaide and the Wheat Initiative — also outlines how this research can be harnessed on a global level to further accelerate climate resilience in staple crops.

“An advantage of understanding abiotic stress at the level of plant physiology is that many of the same tools and methods can be applied across a range of crops that face similar problems,” said first author and CIMMYT wheat physiologist Matthew Reynolds.

Abiotic stresses such as temperature extremes and drought can have devastating impacts on plant growth and yields, posing a massive risk to food security.

Harnessing research across a global wheat improvement network for climate resilience: research gaps, interactive goals, and outcomes.
Harnessing research across a global wheat improvement network for climate resilience: research gaps, interactive goals, and outcomes.

Addressing research gaps

The authors identified nine key research gaps in efforts to boost climate resilience in wheat, including limited genetic diversity for climate resilience, a need for smarter strategies for stacking traits and addressing the bottleneck between basic plant research and its application in breeding.

Based on a combination of the latest research advances and tried-and-tested breeding methods, the scientists are developing strategies to address these gaps. These include:

  • Using big data analysis to better understand stress profiles in target environments and design wheat lines with appropriate heat and drought adaptive traits.
  • Exploring wheat genetic resources for discovery of novel traits and genes and their use in breeding.
  • Accelerating genetic gains through selection techniques that combine phenomics with genomics.
  • Crowd-sourcing new ideas and technologies from academia and testing them in real-life breeding situations.

These strategies will be thoroughly tested at the Heat and Drought Wheat Improvement Network (HeDWIC) Hub under realistic breeding conditions and then disseminated to other wheat breeding programs around the world facing similar challenges.

One factor that strongly influences the success and acceleration of climate resilience technologies, according to Reynolds, is the gap between theoretical discovery research and crop improvement in the field.

“Many great ideas on how to improve climate-resilience of crops pile up in the literature, but often remain ‘on the shelf’ because the research space between theory and practice falls between the radar of academia on the one hand, and that of plant breeders on the other,” Reynolds explained.

Translational research — efforts to convert basic research knowledge about plants into practical applications in crop improvement — represents a necessary link between the world of fundamental discovery and farmers’ fields and aims to bridge this gap.

Main research steps involved in translating promising technologies into genetic gains (graphical abstract, adapted from Reynolds and Langridge, 2016). Reprinted under licence CC BY-NC-ND.
Main research steps involved in translating promising technologies into genetic gains (graphical abstract, adapted from Reynolds and Langridge, 2016). Reprinted under licence CC BY-NC-ND.

The impacts of this research, conducted under HeDWIC — a project led by CIMMYT in partnership with experts around the world — will be validated on a global scale through the International Wheat Improvement Network (IWIN), with the potential to reach at least half of the world’s wheat-growing area.

The results will benefit breeders and researchers but, most importantly, farmers and consumers around the world who rely on wheat for their livelihoods and their diets. Wheat accounts for about 20% of all human calories and protein, making it a pillar of food security. For about 1.5 billion resource-poor people, wheat is their main daily staple food.

With the world population projected to rise to almost ten billion by 2050, demand for food is predicted to increase with it. This is especially so for wheat, being a versatile crop both in terms of where it can grow and its many culinary and industrial uses. However, current wheat yield gains will not meet 2050 demand unless serious action is taken. Translational research and strategic breeding are crucial elements in ensuring that research is translated into higher and stable yields to meet these challenges.

Read the full study:
Harnessing translational research in wheat for climate resilience

Cover photo: Wheat fields at CIMMYT’s experimental stations near Ciudad Obregón, Sonora state, Mexico. (Photo: M. Ellis/CIMMYT)

A challenge solved

Wheat stalks grow in a in India. (Photo: Saad Akhtar)
Wheat stalks grow in a field in India. (Photo: Saad Akhtar)

For scientists, determining how best to increase wheat yields to meet food demand is a persistent challenge, particularly as the trend toward sustainably intensifying production on agricultural lands grows.

The United Nations projects that the current global population of 7.6 billion will increase to more than 9.8 billion by 2050, making higher grain yield potential vital, particularly as climate instability increases due to global warming. International efforts are also focused on meeting the Zero Hunger target detailed in the UN Sustainable Development Goals before they expire in 2030.

Now, a new landmark research survey on the grain yield potential and climate-resilience of bread wheat (Triticum aestivum L.) has brought scientists a few strides closer to meeting their ambitions.

Grain yield has traditionally been an elusive trait in genomic wheat breeding because of its quantitative genetic control, which means that it is controlled by many genomic regions with small effects.

Challenges also include a lack of good understanding about the genetic basis of grain yield, inconsistent grain yield quantitative trait loci identified in different environments, low heritability of grain yield across environments and environment interactions of grain yield.

To dissect the genetic architecture of wheat grain yield for the purposes of the research, which appeared in Scientific Reports, researchers implemented a large-scale genome-wide association study based on 100 datasets and 105,000 grain yield observations from 55,568 wheat breeding lines developed by the International Maize and Wheat Improvement Center (CIMMYT).

They evaluated the lines between 2003 and 2019 in different sites, years, planting systems, irrigation systems and abiotic stresses at CIMMYT’s primary yield testing site, the Norman E. Borlaug Experimental Research Station, Ciudad Obregon, Mexico, and in an additional eight countries — including Afghanistan, India and Myanmar — through partnerships with national programs.

The researchers also generated the grain-yield associated marker profiles and analyzed the grain-yield favorable allele frequencies for a large panel of 73,142 wheat lines, resulting in 44.5 million data points. The marker profiles indicated that the CIMMYT global wheat germplasm is rich in grain yield favorable alleles and is a trove for breeders to choose parents and design strategic crosses based on complementary grain yield alleles at desired loci.

“By dissecting the genetic basis of the elusive grain-yield trait, the resources presented in our study provide great opportunities to accelerate genomic breeding for high-yielding and climate-resilient wheat varieties, which is a major objective of the Accelerating Genetic Gain in Maize and Wheat project,” said CIMMYT wheat breeder Philomin Juliana.

“This study is unique and the largest-of-its-kind focusing on elucidating the genetic architecture of wheat grain yield,” she explained, “a highly complex and economically important trait that will have great implications on future diagnostic marker development, gene discovery, marker-assisted selection and genomic-breeding in wheat.”

Currently, crop breeding methods and agronomic management put annual productivity increases at 1.2% a year, but to ensure food security for future generations, productivity should be at 2.4% a year.

So, the extensive datasets and results presented in this study are expected to provide a framework for breeders to design effective strategies for mitigating the effects of climate change, while ensuring food-sustainability and security.

Five big steps toward wheat self-sufficiency in Pakistan

A seed vendor near Islamabad, Pakistan. For improved crop varieties to reach the farmers who need them, they usually must first reach local vendors, who form an essential link in the chain between researchers, seed producers and farmers. (Photo: M. DeFreese/CIMMYT)
A seed vendor near Islamabad, Pakistan. For improved crop varieties to reach the farmers who need them, they usually must first reach local vendors, who form an essential link in the chain between researchers, seed producers and farmers. (Photo: M. DeFreese/CIMMYT)

Wheat is not just an essential part of the Pakistani diet, but also absolutely critical to the country’s economy and to the farmers who cultivate it. The government of Pakistan’s goal to achieve self-sufficiency in wheat production just became more attainable with the release of five new wheat varieties. These new seeds could help the country’s 8.8 million hectares of wheat-farmed area become more productive, climate-resilient and disease-resistant — a welcome development in a region where new climate change scenarios threaten sustained wheat production.

With multiple years of on-station and on-farm testing, the Wheat Research Institute (WRI) in Faisalabad, the Arid Zone Research Institute (AZRI) in Bhakhar, and the Barani Agricultural Research Institute in Chakwal released five varieties: Subhani 2021, MH-2021, Dilkash-2021, Bhakkar-20 and MA-2020.

The varieties, drawn from germplasm from the International Maize and Wheat Improvement Center (CIMMYT), were developed for different production environments in the Punjab province of Pakistan.

Dilkash-2021 was developed by WRI from a cross with a locally developed wheat line and a CIMMYT wheat line. MH-2021 and MA-2020 were selected from the CIMMYT wheat breeding germplasm through international trials and nurseries.

Subhani-21 and MA-2020 were selected from special trials assembled by CIMMYT for expanded testing, early access and genomic selection under the USAID-funded Feed the Future Innovation Lab for Applied Wheat Genomics at Kansas State University, in partnership with Cornell University and four South Asian countries (Bangladesh, India, Nepal and Pakistan).

Over the course of multiple years and locations, the new varieties exhibited a yield potential that is 5 to 20% higher than current popular varieties such as Faisalabad 2008, in addition to good grain quality and attainable yields of over 7 tons per hectare. They also showed an impressive resistance to leaf and yellow rusts, compatibility with wheat-rice and wheat-cotton farming systems, and resilience to stresses.

“It is exciting to see new varieties coming out of these collaborative projects between the Pakistani breeding programs, CIMMYT and the university teams,” said Jesse Poland, associate professor at Kansas State University and director of the Wheat Genomics Innovation Lab.

Wheat breeder and WRI director Javed Ahmad (center, wearing a white cap) explains the performance of a new variety and its positive traits to visitors. (Photo: Muhammad Shahbaz Rafiq)
Wheat breeder and WRI director Javed Ahmad (center, wearing a white cap) explains the performance of a new variety and its positive traits to visitors. (Photo: Muhammad Shahbaz Rafiq)

Closing the yield gap between research fields and smallholder fields

Despite all of these encouraging traits, releasing a new variety is just half of the battle. The other half is getting these new, quality seeds to markets quickly so that wheat growers can realize the benefits. A fast-track seed multiplication program for each of these varieties has been designed and implemented.

“Pakistan has started to multiply early-generation seeds of rust-resistant varieties. These will be available to seed companies for multiplication and provision to farmers in the shortest possible time,” agreed wheat breeder and WRI Director Javed Ahmad and the National Wheat Coordinator Atiq Rattu.

Wheat breeder and WRI director Javed Ahmad (left) discusses performance of the new varieties with a colleague. (Photo: Muhammad Shahbaz Rafiq)
Wheat breeder and WRI director Javed Ahmad (left) discusses performance of the new varieties with a colleague. (Photo: Muhammad Shahbaz Rafiq)

However, the current seed replacement rate is still low, mainly because new, quality seeds are rarely available at the right time, location, quantity, and price for smallholders. Strengthening and diversifying seed production of newly released varieties can be done by decentralizing seed marketing and distribution systems and engaging both public and private sector actors. Additionally, marketing and training efforts need to be improved for women, who are mostly responsible for household-level seed production and seed care.

In 2020, Pakistan harvested 25.7 million tons of wheat, up from 23.3 million tons a decade ago in 2010, which roughly matches its annual consumption of the crop. Pakistan is coming close to its goal of self-sufficiency, as outlined in the Pakistan Vision 2025, Food Security Policy 2018 and Vision for Agriculture 2030. Research shows that the public sector cannot extensively disseminate seeds alone; new policies must create an attractive environment to private sector partners, so that entrepreneurs are also attracted to the seed business.  With continued efforts and a bold distribution and training effort, new releases like these will contribute to narrowing the yield gap between research stations and farmers’ fields.

First complete cytological characterization of the 2NvS translocation

Wheat infected with the blast fungus in Meherpur, Bangladesh, in 2019. (Photo: PLOS Biology)
Wheat infected with the blast fungus in Meherpur, Bangladesh, in 2019. (Photo: PLOS Biology)

As scientists study and learn more about the complicated genetic makeup of the wheat genome, one chromosomal segment has stood out, particularly in efforts to breed high-yielding wheat varieties resistant to devastating and quickly spreading wheat diseases.

Known as the 2NvS translocation, this segment on the wheat genome has been associated with grain yield, tolerance to wheat stems bending over or lodging, and multiple-disease resistance.

Now, thanks to a new multi-institution study led by wheat scientist Liangliang Gao of Kansas State University, we have a clearer picture of the yield advantage and disease resistance conferred by this chromosomal segment for wheat farmers — and more opportunities to capitalize on these benefits for future breeding efforts.

The Aegilops ventricosa 2NvS segment in bread wheat: cytology, genomics and breeding, published in Theoretical and Applied Genetics, summarizes the collaborative effort by scientists from several scientific institutions — including International Maize and Wheat Improvement Center (CIMMYT) head of global wheat improvement Ravi Singh and wheat scientist Philomin Juliana —  to conduct the first complete cytological characterization of the 2NvS translocation.

A rich background

The 2NvS translocation segment has been very valuable in disease-resistance wheat breeding since the early 1990s. Originally introduced into wheat cultivar VPM1 by the French cytogeneticist Gerard Doussinault in 1983 by crossing with a wild wheat relative called Aegilops ventricosa, the segment has been conferring resistance to diseases like eye spot (Pch1 gene), leaf rust (Lr37 gene), stem rust (Sr38 gene), stripe rust (Yr17 gene), cereal cyst (Cre5 gene), root knot (Rkn3 gene) and wheat blast.

The high-yielding blast-resistant CIMMYT-derived varieties BARI Gom 33 and WMRI#3 (equivalent to Borlaug100),released in Bangladesh to combat a devastating outbreak of wheat blast in the region, carry the 2NvS translocation segment for blast resistance.

Earlier research by Juliana and others found that the proportion of lines with the 2NvS translocation had increased by 113.8% over seven years in CIMMYT’s international bread wheat screening nurseries: from 44% in 2012 to 94.1% in 2019. It had also increased by 524.3% in the semi-arid wheat screening nurseries: from 15% in 2012 to 93.7% in 2019. This study validates these findings, further demonstrating an increasing frequency of the 2NvS translocation in spring and winter wheat breeding programs over the past two decades.

New discoveries

The authors of this study completed a novel assembly and functional annotation of the genes in the 2NvS translocation using the winter bread wheat cultivar Jagger. They validated it using the spring wheat cultivar CDC Stanley and estimated the actual size of the segment to be approximately 33 mega base pairs.

Their findings substantiate that the 2NvS region is rich in disease resistance genes, with more than 10% of the 535 high-confidence genes annotated in this region belonging to the nucleotide-binding leucine-rich repeat (NLR) gene families known to be associated with disease resistance.  This was a higher number of NLRs compared to the wheat segment of the Chinese Spring reference genome that was replaced by this segment, adding further evidence to its multiple-disease resistant nature.

In addition to being an invaluable region for disease resistance, the study makes a strong case that the 2NvS region also confers a yield advantage.  The authors performed yield association analyses using yield data on lines from the Kansas State University wheat breeding program, the USDA Regional Performance Nursery —comprising lines from central US winter wheat breeding programs — and the CIMMYT spring bread wheat breeding program, and found a strong association between the presence of the segment and higher yield.

Global benefits

The yield and disease resistance associations of the 2NvS genetic segment have been helping farmers for years, as seen in the high proportion of the segment present in the improved wheat germplasm distributed globally through CIMMYT’s nurseries.

“The high frequency of the valuable 2NvS translocation in CIMMYT’s internationally distributed germplasm demonstrates well how CIMMYT has served as a key disseminator of lines with this translocation globally that would have likely contributed to a large impact on global wheat production,” said study co-author Juliana.

Through CIMMYT’s distribution efforts, it is likely that national breeding programs have also effectively used this translocation, in addition to releasing many 2NvS-carrying varieties selected directly from CIMMYT distributed nurseries.

With this study, we now know more about why the segment is so ubiquitous and have more tools at our disposal to use it more deliberately to raise yield and combat disease for wheat farmers into the future.

Scientific opportunities and challenges

Maize and wheat fields at the El Batán experimental station. (Photo: CIMMYT/Alfonso Cortés)
Maize and wheat fields at the El Batán experimental station. (Photo: CIMMYT/Alfonso Cortés)

The first meetings of the Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) wheat and maize science and technical steering committees — WSC and MSC, respectively — took place virtually on 25th and 28th September.

Researchers from the International Maize and Wheat Improvement Center (CIMMYT) sit on both committees. In the WSC they are joined by wheat experts from national agricultural research systems (NARS) in Bangladesh, Ethiopia, Kenya, India, and Nepal; and from Angus Wheat Consultants, the Foreign, Commonwealth & Development Office (FCDO), HarvestPlusKansas State University and the Roslin Institute.

Similarly, the MSC includes maize experts from NARS in Ethiopia, Ghana, Kenya and Zambia; and from Corteva, the Foundation for Food and Agriculture Research (FFAR), the International Institute for Tropical Agriculture (IITA), SeedCo, Syngenta, the University of Queensland, and the US Agency for International Development (USAID).

During the meetings, attendees discussed scientific challenges and opportunities for AGG, and developed specific recommendations pertaining to key topics including breeding and testing scheme optimization, effective engagement with partners and capacity development in the time of COVID-19, and seed systems and gender intentionality.

Discussion groups noted, for example, the need to address family structure in yield trials, to strengthen collaboration with national partners, and to develop effective regional on-farm testing strategies. Interestingly, most of the recommendations are applicable and valuable for both crop teams, and this is a clear example of the synergies we expect from combining maize and wheat within the AGG project.

All the recommendations will be further analyzed by the AGG teams during coming months, and project activities will be adjusted or implemented as appropriate. A brief report will be submitted to the respective STSCs prior to the second meetings of these committees, likely in late March 2021.

The value of research on plant resistance to insects

Crop pest outbreaks are a serious threat to food security worldwide. Swarms of locusts continue to form in the Horn of Africa, threatening food security and farmer livelihoods ahead of a new cropping season. The devastating fall armyworm continues cause extensive damage in Africa and South Asia.

With almost 40% of food crops lost annually due to pests and diseases, plants resistance to insects is more important than ever. Last month, a group of wheat breeders and entomologists came together for the 24th Biannual International Plant Resistance to Insects (IPRI) Workshop, held at the International Maize and Wheat Improvement Center (CIMMYT) global headquarters outside Mexico City.

Watch Mike Smith, entomologist and distinguished professor emeritus at Kansas State University explain the importance of working with economists to document the value of plant insect resistance research, and why communication is crucial for raising awareness of the threat of crop pests and insect resistance solutions.

What is wheat blast?

What is wheat blast disease?

Wheat blast is a fast-acting and devastating fungal disease that threatens food safety and security in tropical areas in South America and South Asia. Directly striking the wheat ear, wheat blast can shrivel and deform the grain in less than a week from the first symptoms, leaving farmers no time to act.

The disease, caused by the fungus Magnaporthe oryzae pathotype triticum (MoT), can spread through infected seeds and survives on crop residues, as well as by spores that can travel long distances in the air.

Magnaporthe oryzae can infect many grasses, including barley, lolium, rice, and wheat, but specific isolates of this pathogen generally infect limited species; that is, wheat isolates infect preferably wheat plants but can use several more cereal and grass species as alternate hosts. The Bangladesh wheat blast isolate is being studied to determine its host range. The Magnaporthe oryzae genome is well-studied but major gaps remain in knowledge about its epidemiology.

The pathogen can infect all aerial wheat plant parts, but maximum damage is done when it infects the wheat ear. It can shrivel and deform the grain in less than a week from first symptoms, leaving farmers no time to act.
The pathogen can infect all aerial wheat plant parts, but maximum damage is done when it infects the wheat ear. It can shrivel and deform the grain in less than a week from first symptoms, leaving farmers no time to act.

Where is wheat blast found?

First officially identified in Brazil in 1985, the disease is widespread in South American wheat fields, affecting as much as 3 million hectares in the early 1990s. It continues to seriously threaten the potential for wheat cropping in the region.

In 2016, wheat blast spread to Bangladesh, which suffered a severe outbreak. It has impacted around 15,000 hectares of land in eight districts, reducing yield on average by as much as 51% in the affected fields.

Wheat-producing countries and presence of wheat blast.
Wheat-producing countries and presence of wheat blast.

How does blast infect a wheat crop?

Wheat blast spreads through infected seeds, crop residues as well as by spores that can travel long distances in the air.

Blast appears sporadically on wheat and grows well on numerous other plants and crops, so rotations do not control it. The irregular frequency of outbreaks also makes it hard to understand or predict the precise conditions for disease development, or to methodically select resistant wheat lines.

At present blast requires concurrent heat and humidity to develop and is confined to areas with those conditions. However, crop fungi are known to mutate and adapt to new conditions, which should be considered in management efforts.

How can farmers prevent and manage wheat blast?

There are no widely available resistant varieties, and fungicides are expensive and provide only a partial defense. They are also often hard to obtain or use in the regions where blast occurs, and must be applied well before any symptoms appear — a prohibitive expense for many farmers.

The Magnaporthe oryzae fungus is physiologically and genetically complex, so even after more than three decades, scientists do not fully understand how it interacts with wheat or which genes in wheat confer durable resistance.

Researchers from the International Maize and Wheat Improvement Center (CIMMYT) are partnering with national researchers and meteorological agencies on ways to work towards solutions to mitigate the threat of wheat blast and increase the resilience of smallholder farmers in the region. Through the USAID-supported Cereal Systems Initiative for South Asia (CSISA) and Climate Services for Resilient Development (CSRD) projects, CIMMYT and its partners are developing agronomic methods and early warning systems so farmers can prepare for and reduce the impact of wheat blast.

CIMMYT works in a global collaboration to mitigate the threat of wheat blast, funded by the Australian Centre for International Agricultural Research (ACIAR), the CGIAR Research Program on Wheat (WHEAT), the Indian Council of Agricultural Research (ICAR) and the Swedish Research Council (Vetenskapsrådet). Some of the partners who collaborate include the Bangladesh Wheat and Maize Research Institute (BWMRI), Bolivia’s Instituto Nacional de Innovación Agropecuaria y Forestal (INIAF), Kansas State University and the Agricultural Research Service of the US (USDA-ARS).