The International Maize and Wheat Improvement Center (CIMMYT) was awarded a $5 million grant from the Foundation for Food and Agriculture Research (FFAR) to develop climate-resilient wheat.
Read more: https://www.world-grain.com/articles/14718-cimmyt-working-to-create-climate-resilient-wheat
Wheat constitutes 20% of all calories and protein consumed, making it a cornerstone of the human diet, according to the United Nations. However, hotter and drier weather, driven by a changing climate, threatens the global wheat supply. To address this threat, the Foundation for Food and Agriculture Research (FFAR) awarded a $5 million grant to the International Maize and Wheat Improvement Center (CIMMYT) to develop climate-resilient wheat. CIMMYT leads global research programs on maize and wheat, sustainable cropping systems and policies to improve farmers’ livelihoods. These activities have driven major gains in wheat variety improvement across the globe for decades; in the US alone, for example, over 50% of the wheat acreage is sown with CIMMYT-related varieties.
Wheat is among the most widely grown cereal crops in the world and the third-largest crop grown in the US by acre. Nearly all US wheat crops are improved and supported by public agriculture research. As most wheat in the US is dependent on rainfall and has no access to irrigation, this research is critical for helping the plants — and producers — weather climatic changes including extreme heat and drought. Additionally, the demand for wheat is expected to rise in the coming years — as much as 60% by 2050. Without public research, wheat production could decrease by nearly 30% over the same period due to extreme climate conditions.
“FFAR leverages public agriculture research funding through public-private partnerships to pioneer actionable research. With temperatures on the rise and water becoming scarcer, we are committed to supporting wheat farmers and providing new wheat varieties designed with future environmental challenges in mind,” said FFAR’s Executive Director Sally Rockey.
Using the FFAR grant, CIMMYT researchers are pioneering wheat breeding technologies to produce heat-tolerant, drought-resistant and climate-resilient wheat.
CIMMYT researchers and collaborators are applying cutting-edge approaches in genomics, remote sensing and big data analysis to develop new breeding technologies. A key intervention will explore the vast and underutilized reserve of wheat genetic resources to fortify the crop against current and future climate-related stresses.
“This project will help bridge a longstanding gap between state-of-the-art technological findings and crop improvement to deliver climate resilient wheat to farmers as quickly as possible,” said Matthew Reynolds, head of Wheat Physiology at CIMMYT and principal investigator of the project.
Breakthroughs from the FFAR funded project will achieve impact for growers via the International Wheat Improvement Network (IWIN) that supplies new wheat lines to public and private breeding programs worldwide, and has boosted productivity and livelihoods for wheat farmers for over half a century, especially in the Global South.
The research and breeding supported by FFAR will be conducted under the Heat and Drought Wheat Improvement Consortium (HeDWIC), a project led by CIMMYT in partnership with experts across the globe, designed to ensure wheat’s long-term climate resilience. Under the umbrella of the Wheat Initiative’s AHEAD unit, the most relevant advances in academia will be channeled to HeDWIC to help further boost impacts.
“‘Heat,’ ‘drought’ and ‘wheat’ are three of the most important words for billions of people,” said CIMMYT Interim Deputy Director for Research Kevin Pixley. “This partnership between CIMMYT and FFAR will help ensure that the best agricultural science is applied to sustainably raise production of one of the world’s most important staple crops, despite unprecedented challenges.”
CIMMYT Director General Martin Kropff said, “This project represents not only a breakthrough to develop wheat for the future, but also an emerging partnership between CIMMYT and FFAR. I look forward to a productive collaboration that will move us all closer to our mission of maize and wheat science for improved livelihoods.”
FFAR’s investment was matched by co-investments from the CGIAR Research Program on Wheat (WHEAT) and Accelerating Genetic Gains for Maize and Wheat (AGG), a project which is jointly funded by the Bill & Melinda Gates Foundation and the UK Foreign, Commonwealth, and Development Office (FCDO).
FOR MORE INFORMATION, OR TO ARRANGE INTERVIEWS, CONTACT:
Marcia MacNeil, Communications Officer, CGIAR Research Program on Wheat, CIMMYT. +52 5951148943, m.macneil@cgiar.org
Brian Oakes, FFAR. +1 202-604-5756, boakes@foundationfar.org
About the Foundation for Food & Agriculture Research
The Foundation for Food & Agriculture Research (FFAR) builds public-private partnerships to fund bold research addressing big food and agriculture challenges. FFAR was established in the 2014 Farm Bill to increase public agriculture research investments, fill knowledge gaps and complement USDA’s research agenda. FFAR’s model matches federal funding from Congress with private funding, delivering a powerful return on taxpayer investment. Through collaboration and partnerships, FFAR advances actionable science benefiting farmers, consumers and the environment.
Connect: @FoundationFAR | @RockTalking
About CIMMYT
The International Maize and Wheat Improvement Center (CIMMYT) is the global leader in publicly-funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of 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.
For more information, visit staging.cimmyt.org
The International Maize and Wheat Improvement Center (CIMMYT) is pleased to announce the successful development of three CIMMYT-derived fall armyworm-tolerant elite maize hybrids for eastern and southern Africa.
Fall armyworm (Spodoptera frugiperda) emerged as a serious threat to maize production in Africa in 2016 before spreading to Asia in 2018. Host plant resistance is an important component of integrated pest management (IPM). By leveraging tropical insect-resistant maize germplasm developed in Mexico, coupled with elite stress-resilient maize germplasm developed in sub-Saharan Africa, CIMMYT worked intensively over the past three years to identify and validate sources of native genetic resistance to fall armyworm in Africa. This included screening over 3,500 hybrids in 2018 and 2019.
Based on the results of on-station screenhouse trials for fall armyworm tolerance (under artificial infestation) conducted at Kiboko during 2017-2019, CIMMYT researchers evaluated in 2020 a set of eight test hybrids (four early-maturing and four intermediate-maturing) ) against four widely used commercial hybrids (two early- and two intermediate-maturing) as checks. The trials conducted were:
The eight test entries with fall armyworm tolerance were also included in the regional on-station trials (comprising a total of 58 entries) evaluated at 28 locations in Kenya and Tanzania. The purpose of these regional trials was to collect data on agronomic performance.
Summary of the data
Native genetic resistance to fall armyworm in maize is partial, though quite significant in terms of yield protection under severe fall armyworm infestation, as compared to the susceptible commercial checks. Sustainable control of fall armyworm is best achieved when farmers use host plant resistance in combination with other components of integrated pest management, including good agronomic management, biological control and environmentally safer pesticides.
Next Steps
Together with national agricultural research system (NARS) partners, CIMMYT will nominate these FAWTH hybrids for varietal release in target countries in sub-Saharan Africa, especially in eastern and southern Africa. After national performance trials (NPTs) and varietal release and registration, the hybrids will be sublicensed to seed company partners on a non-exclusive, royalty-free basis for accelerated seed scaling and deployment for the benefit of farming communities.
Acknowledgements
This work was implemented with funding support from the CGIAR Research Program on Maize (MAIZE), the U.S. Agency for International Development (USAID) Feed the Future initiative, and the Bill & Melinda Gates Foundation. MAIZE receives Windows 1&2 funding support from the World Bank and the Governments of Australia, Belgium, Canada, China, France, India, Japan, Korea, Mexico, Netherlands, New Zealand, Norway, Sweden, Switzerland, UK and USA. The support extended by the Kenya Agriculture & Livestock Research Organization (KALRO) for implementation of this work through the fall armyworm mass rearing facility at Katumani and the maize research facilities managed by CIMMYT at Kiboko is gratefully acknowledged.
For further information, please contact:
B.M. Prasanna, Director of the Global Maize Program, CIMMYT and the CGIAR Research Program on Maize. b.m.prasanna@cgiar.org
The agricultural sector is possibly the largest livelihood provider in India, with the smallholder farming community in the vast Indo-Gangetic Plains making the bulk of it. They are the community responsible for growing the food available on our table. In celebration of India’s National Farmer’s Day on December 23 — known in Hindi as Kisan Diwas — we share the story of a farmer-turned-entrepreneur from eastern Uttar Pradesh, where the International Maize and Wheat Improvement Center (CIMMYT) and its partners have invested in supporting smallholder farmers to implement best farming practices and improve yields through sustainable intensification.
“I am a farmer and I am hopeful of a future for my children in the farming sector,” says Surender Prasad, a 52-year-old farmer from Umila village in Santkabir Nagar district, Uttar Pradesh. Prasad is one of the innovative farmers in and around the district who has time and again strived to introduce new implements and technologies on his farm — often a big risk for smallholders like him.
In 2014, Prasad met researchers from CIMMYT’s Cereal Systems Initiative for South Asia (CSISA) project while visiting the village Lazar Mahadeva during an inter-district traveling seminar. After seeing the farmer demonstration plots for himself — which, incidentally, is one of the best ways of raising farmer awareness in the region — Prasad was convinced of the efficiency of transplanting rice by machine and using zero tillage in wheat production.
Through his continued association with the project, Prasad has now adopted both practices, in addition to direct seeded rice (DSR) and Laser Land Levelling. With a single 35 horsepower tractor, cultivator and harrow, Prasad was able to improve his wheat grain yield by one ton per hectare during the 2014-15 cropping season, and secure improved profit margins as a result.
Encouraged by these results, in 2018 Prasad purchased a 55 horsepower New Holland Tractor, a Happy Seeder, a tractor-mounted sprayer and other machinery for custom hire under the state government’s machinery bank scheme. His aspiration for entrepreneurship grew in the months following these purchases and he has since established himself as a local service provider, alongside his role as a farmer. According to Prasad, his continued association with CSISA and its network of partners helped him gain better technical knowledge and skills as well as confidence with using conservation agriculture-based machinery, thanks to trainings provided by the project team.
A budding entrepreneur
Today Prasad is an important entrepreneur in the region, providing custom hiring services for Happy Seeder and DSR and promoting agricultural mechanization in his community. Going forward, scale-appropriate farm mechanization will help farmers in the area to intensify their cropping system at a lower cost, supported by use of the conservation agriculture approaches encouraged by the CSISA project team, which have been shown to improve yields, reduce farmer costs and preserve natural resources. For example, using these best management practices Prasad was able to harvest an additional 1.1 tons of wheat from the 10 acres of land owned by him and his brother, and most farmers in his village now follow his crop management advice.
He is quick to adopt new ideas and has become something of an influencer in the area, earning him friends among the farming community and helping the CSISA team reach more farmers with new innovations.
This year the opportunity for hiring out mechanization services has been immense, largely due to the impact of the COVID-19 pandemic, which has created difficulties for farmers engaged in rice transplanting. As a result, Prasad managed to sow 90 acres of DSR on his own farm and in the nearby village, as well as seeding 105 acres of wheat in the fall 2020 season. “Thanks to mechanization we were far less affected by the COVID-19 disruptions and managed to plant rice and then wheat without much delay,” he explains. Prasad also provided tractor-mounted sprayer services for applying herbicides and insecticide on 90 acres of rice crop. Considering these successes, he has now planned to offer year-round extension services.
“I feel overwhelmed after serving my own community as a service provider,” says Prasad. “I feel proud of myself when other farmers come asking for my assistance.” Endorsing his contribution as an innovative farmer, the Department of Agriculture for the Government of Uttar Pradesh recognized him with awards in 2015 and 2019. He attributes his success to his exposure to CSISA interventions and support and believes that CSISA acted as a facilitator, encouraging him to use his ideas for his own benefit and for the benefit of the larger agrarian community around him.
As one of the pioneer homegrown seed companies in Uganda, Farm Inputs Care Centre (FICA) has become one of the leading players in the seed sector value chain. Since its inception in 1999, it has played a significant role in variety development and maintenance, seed production, and processing, packaging and marketing.
The close linkages it has maintained with partners such as National Agriculture Research Organization (NARO)’s National Crops Resources Research Institute (NaCCRI) and the International Maize and Wheat Improvement Center (CIMMYT) have seen it acquire new hybrids for commercialization and production of early generation seed.
A unique opportunity for collaboration
Recurrent plant threats such as drought, pests and diseases — alongside the perpetual need to develop and foster better performing varieties in changing climatic conditions — has required partners to intensify efforts to tackle these challenges to bolster smallholders’ resilience. The Drought Tolerant Maize for Africa (DTMA) project, for instance, ushered in the partnership between CIMMYT, FICA, national agriculture research systems, and other partners to develop and scale up well-adapted, drought-tolerant maize varieties among farmers in Uganda and elsewhere in sub-Saharan Africa.
“One of the unique features of the collaboration is that besides CIMMYT, there was a multi-stakeholder platform that would convene key seed sector players to discuss issues affecting the industry. Ultimately, this benefitted the farmers,” says FICA’s Chief Executive Officer Narcis Tumushabe.
This partnership continued during the Stress Tolerant Maize for Africa (STMA) initiative — which ran from 2016 to2020 — and now, in the Accelerating Genetic Gains in Maize and Wheat (AGG) project, which launched in July 2020 with the ambition of fast-tracking the development of climate-resilient, higher-yielding, demand-driven, gender-responsive and nutritious maize and wheat varieties.
Tumushabe is happy that the hybrids delivered in the DTMA and STMA projects proved worthwhile against multiple stresses in farmers’ fields, offering reliable yields even in challenging conditions like drought or other stresses. Because of the diverse ecological zones in Uganda, it was essential to test the hybrids FICA accessed through the CIMMYT-NARO partnership across different ecological zones, ahead of commercialization. This has given farmers opportunities to choose the varieties that are suitable in their environment. The five varieties FICA chose to promote include Longe 9H — which produces about 700 metric tons annually — and WE 2114, WE 2115, WE 3106 and UH 5355, which cumulatively produce about 1,300 tons annually.
The WE 3106 variety has a strong stem and produces big cobs and Tumushabe notes that some livestock farmers prefer this variety as a good forage source for their livestock. Large-scale commercial farmers prefer WE 2114 due to the positioning of the ears at a uniform height, which makes it easy for harvesting using combine harvesters.
Additionally, FICA breeders have also developed impactful combination hybrids using CIMMYT and FICA lines and the company looks to double its annual production of certified stress-tolerant maize seed to 4,000 metric tons in the next five years. Currently, it enlists about 800 contract seed growers to support its seed multiplication efforts.
Surmounting monumental challenges for varietal turnover
Promoting new seed varieties, especially in a highly competitive market, is no mean task. With the seed delivery systems in sub-Saharan Africa mainly driven by the supply side, seed companies end up multiplying only the popular varieties that are already in high demand, explains Mosisa Worku Regasa, a seed systems specialist at CIMMYT.
“Consequently, these companies become reluctant to multiply new seed varieties due to deficient demand, thereby slowing down the rate of varietal turnover,” says Mosisa. “There is, however, a growing push for a demand-driven system.”
“Some avenues for cultivating a demand-led environment include investing a great deal of resources to better understand farmers’ preferences or product profiles, setting up numerous demonstration plots for newer, better-performing varieties closer to the farmers locations in addition to investing in other marketing and promotional activities.”
Still, the seed sector must confront other dynamics such as farmers that are captive of old albeit popular varieties.
“There are cases where, depending on the stage of a seed company’s development, the number of products that one can deliver in the right quality and appropriate maintenance level has to be limited or realistically managed,” Tumushabe explains.
“The seed company also ought to be sure that the new variety will be superior to existing varieties under farmers’ conditions. That is why one may find little excitement if the genetic gain of a new crop variety is not significantly high compared to the already known and available crop variety. This may make one wonder why an old variety continues to persist in the market.”
To create awareness and sustain the demand for its seed, FICA has established demonstration farms to showcase the performance of its stress-resilient maize varieties among farmers and engaged agro-dealers as last mile seed merchants. It is also during field days held at demonstration farms where the company obtains feedback on how to improve its breeding program, particularly from women smallholder farmers. Such efforts have helped raise the company’s share of stress-tolerant maize seed production to 70% of the total maize seed it produces, which indicates good progress in variety replacement.
New research by an international team of scientists, including scientists from the International Maize and Wheat Improvement Center (CIMMYT) and the Indian Council of Agricultural Research (ICAR), shows that adopting a portfolio of conservation agriculture and crop diversification practices is more profitable and better for the environment than conventional agriculture.
Reported last month in Nature Scientific Reports, the results of the study should encourage farmers and policymakers in South Asia to adopt more sustainable crop management solutions such as diversifying crop rotations, direct-seeding rice, zero tillage and crop residue retention.
Rice-wheat has for a long time been the dominant cropping system in the western Indo-Gangetic plains in India. However, issues such as water depletion, soil degradation and environmental quality as well as profitability have plagued farmers, scientists and decision makers for decades. To tackle these issues, researchers and policymakers have been exploring alternative solutions such as diversifying rice with alternative crops like maize.
“Climate change and natural resource degradation are serious threats to smallholder farmers in South Asia that require evidence-based sustainable solutions. ICAR have been working closely with CIMMYT and partners to tackle these threats,” said SK Chaudhari, deputy director general of the Natural Resource Management at ICAR.
In the study, CIMMYT scientists partnered with the ICAR-Central Soil Salinity Research Institute, International Rice Research Institute (IRRI), Borlaug Institute for South Asia (BISA), Swami Keshwan Rajasthan Agriculture University and Cornell University to evaluate seven cropping system management scenarios.
The researchers measured a business-as-usual approach, and six alternative conservation agriculture and crop diversification approaches, across a variety of indicators including profitability, water use and global warming potential.
They found that conservation agriculture-based approaches outperformed conventional farming approaches on a variety of indicators. For example, conservation agriculture-based rice management was found to increase profitability by 12%, while decreasing water use by 19% and global warming potential by 28%. Substituting rice with conservation agriculture-based maize led to improvements in profitability of 16% and dramatic reductions in water use and global warming potential of 84% and 95%. Adding the fast-growing legume mung bean to maize-wheat rotations also increased productivity by 11%, profitability by 25%, and significantly decreased water use by 64% and global warming potential by 106%.
However, CIMMYT Principal Scientist and study co-author M.L. Jat cautioned against the allure of chasing one silver bullet, advising policymakers in South Asia to take a holistic, systems perspective to crop management.
“We know that there are issues relating to water and sustainability, but at the same time we also know that diversifying rice — which is a more stable crop — with other crops is not easy as long as you look at it in isolation,” he explained. “Diversifying crops requires a portfolio of practices, which brings together sustainability, viability and profits.”
With South Asia known as a global “hotspot” for climate vulnerability, and the region’s population expected to rise to 2.4 billion by 2050, food producers are under pressure to produce more while minimizing greenhouse gas emissions and damage to the environment and other natural resources.
“Tackling these challenges requires strong collaborative efforts from researchers, policymakers, development partners and farmers,” said Andrew McDonald, a systems agronomist at Cornell University and co-author of the study. “This study shows this collaboration in action and brings us closer to achieving resilient, nutritious and sustainable food systems.”
“The results of this study show that one-size doesn’t fit all when it comes to sustainable crop management,” said PC Sharma, director of India’s ICAR-Central Soil Salinity Research Institute (ICAR-CSSRI). “Farmers, researchers and policymakers can adopt alternative crop rotations such as maize-wheat or maize-wheat-mung bean, but they can also improve existing rice-wheat rotations using conservation agriculture methods.”
By adopting best practices and established modern tools, national agricultural research systems (NARS) are making data-driven decisions to boost genetic improvement. And they are measuring this progress through tracking and setting goals around “genetic gain.”
Genetic gain means improving seed varieties so that they have a better combination of genes that contribute to desired traits such as higher yields, drought resistance or improved nutrition. Or, more technically, genetic gain measures, “the expected or realized change in average breeding value of a population over at least one cycle of selection for a particular trait of index of traits,” according to the CGIAR Excellence in Breeding (EiB)’s breeding process assessment manual.
CGIAR breeders and their national partners are committed to increasing this rate of improvement to at least 1.5% per year. So, it has become a vital and universal high-level key performance indicator (KPI) for breeding programs.
“We are moving towards a more data-driven culture where decisions are not taken any more based on gut feeling,” EiB’s Eduardo Covarrubias told nearly 200 NARS breeders in a recent webinar on Enhancing and Measuring Genetic Gain. “Decisions that can affect the sustainability and the development of organization need to be based on facts and data.”
Improved metrics. Better decisions. More and better food. But how are NARS positioned to better measure and boost the metric?
EiB researchers have been working with both CGIAR breeding programs and NARS to broaden the understanding of genetic gain and to supply partners with methods and tools to measure it.
The recent webinar, co-sponsored by EiB and the CIMMYT-led Accelerating Genetic Gains in Maize and Wheat (AGG) project, highlighted tools and services that NARS are accessing, such as genotyping, data analysis and mechanization.
Through program assessments, customized expert advice, training and provision of services and resources, EiB researchers are helping national partners arrive at the best processes for driving and measuring genetic gains in their programs.
For example, the EiB team, through Crops to End Hunger (CtEH), is providing guidelines to breeders to help them maximize the accuracy and precision, while reducing the cost of calculating genetic gains. The guidelines make recommendations such as better design of trials and implementing an appropriate check strategy that permits regular and accurate calculation of genetic gain.
A comprehensive example at the project level is EiB’s High-Impact Rice Breeding in East and West Africa (Hi-Rice), which is supporting the modernization of national rice programs in eight key rice-producing countries in Africa. Hi-Rice delivers training and support to modernize programs through tools such as the use of formalized, validated product profiles to better define market needs, genotyping tools for quality control, and digitizing experiment data to better track and improve breeding results. This is helping partners replace old varieties of rice with new ones that have higher yields and protect against elements that attack rice production, such as drought and disease. Over the coming years, EiB researchers expect to see significant improvements in genetic gain from the eight NARS program partners.
And in the domain of wheat and maize, AGG is working in 13 target countries to help breeders adopt best practices and technologies to boost genetic gain. Here, the EiB team is contributing its expertise in helping programs develop their improvement plans — to map out where, when and how programs will invest in making changes.
NARS and CGIAR breeding programs also have access to tools and expertise on adopting a continuous improvement process — one that leads to cultural change and buy-in from leadership so that programs can identify problems and solve them as they come up. Nearly 150 national breeding partners attended another EiB/AGG webinar highlighting continuous improvement key concepts and case studies.
National programs are starting to see the results of these partnerships. The Kenya Agricultural & Livestock Research Organization (KALRO)’s highland maize breeding program has undertaken significant changes to its pipelines. KALRO carried out its first-ever full program costing, and based on this are modifying their pipeline to expand early stage testing. They are also switching to a double haploid breeding scheme with support from the CGIAR Research Program on Maize (MAIZE), in addition to ring fencing their elite germplasm for future crosses.
KALRO has also adopted EiB-supported data management tools, and are working with the team to calculate past rates of genetic gains for their previous 20 years of breeding. These actions — and the resulting data — will help them decide on which tools and methods to adopt in order to improve the rate of genetic gain for highland maize.
“By analyzing historical genetic gain over the last 20 years, it would be interesting to determine if we are still making gains or have reached a plateau,” said KALRO’s Dickson LIgeyo, who presented a Story of Excellence at EiB’s Virtual Meeting 2020. “The assessment will help us select the right breeding methods and tools to improve the program.”
Other NARS programs are on a similar path to effectively measure and increase genetic gain. In Ghana, the rice breeding program at Council for Scientific and Industrial Research (CSIR) have developed product profiles, identified their target market segments, costed out their program, digitized their operations, and have even deployed molecular markers for selection.
With this increased expertise and access to tools and services, national breeding programs are set to make great strides on achieving genetic gain goals.
“NARS in Africa and beyond have been aggressively adopting new ideas and tools,” says EiB’s NARS engagement lead Bish Das. “It will pay a lot of dividends, first through the development of state-of-the-art, and ultimately through improving genetic gains in farmers’ fields. And that’s what it’s all about.”
There is a growing crisis beneath our feet. Scientists, soil specialists and policy-makers around the world are sounding the alarm about degrading soil conditions. And it is particularly stark in developing countries. In fact, about 40 per cent of soils in sub-Saharan Africa are already of poor quality.
Declining soil health causes poor crop yields, leading to further pressure on the soils as farmers struggle to meet food demands and eke out a living. Many farmers lack access to information or technologies to get out of this vicious cycle. If you are a farmer with the need to increase your yield in the face of these challenges, crop breeding and soil management offers a range of solutions as part of an Integrated Soil Fertility Management (ISFM) approach.
For instance, breeding programs which partner with CGIAR Excellence in Breeding (EiB) are working to deliver the best seed varieties for farmers to help them withstand harsh conditions and increase yields. Alongside this work, researchers are supporting farmers to adopt better agronomic practices, such as minimum tillage farming, crop rotation, proper spacing and planting date practices, the use of terracing or intercropping, or techniques to reduce water use.
Of course, breeding cannot happen in a vacuum. To protect soils and produce quality yields, these cropping measures should be closely matched to the best, context-appropriate soil management practices available to farmers, for instance around the type and timing of mineral fertilizer, along with organic sources like crop residues, compost or manure.
Indeed, a combination will bring the best results. But most of the time accessing either improved variety or best agronomic practice represent a challenge for farmers in low income countries.
Here are three ways crop breeders can ensure they deliver the best seeds and create the best conditions for long-term crop production.
Include farmers, agronomic experts and extension services when defining product requirements
Strong connections among public breeding programs and extension and agronomic groups are vital. There is growing discussion regarding how to broaden our work to better consider all the factors that contribute to a successful breeding scheme: genotyping, environment and management (GxExM). However, defining the management component is not easy. Do we breed for conditions that farmers are actually working with, or breed for conditions that they should adopt?
A key to answer this question is a strong breeding team defining the traits needed and wanted by farmers. To design the best product profile, it is imperative to involve extension teams and other groups that work on the development of sustainable agronomic practices.
Properly manage research stations
Attention also needs to focus on the sustainability practices within research stations. It is all too easy to find degraded soil in public research stations. There are many reasons for this: inadequate long-term planning, lack of organized management structures, insufficient connections between breeding and agronomic teams, and lack of resources, to name a few.
Public research stations must serve as an example for the farmers in that specific region. Thus, it is not only what products we develop that matters, but also how we develop them. If we develop a good variety at the research station, but do so without adopting good agronomic practice, what example has been set for farmers and future generations? We need to ensure we invest in the best soil management practices along every step of the research phase.
Breed for specific soil characteristics
Once the breeding target is known, breeding for specific soil conditions is critical. This means developing varieties for soil conditions such as nutrient deficiencies or high salinity levels. CGIAR breeding programs have put in tremendous efforts with great impact here.
For example, AfricaRice and partners developed rice varieties branded ARICA (Advanced Rice Varieties for Africa) to be salt or iron toxicity tolerant, among other traits. This is helping farmers who farm under predominantly rainfed conditions, in which soils and yields are threatened by floods, droughts and toxicity.
Another standout product is Stress Tolerant Maize for Africa (STMA), led by the International Maize and Wheat Improvement Center (CIMMYT) and the International Institute of Tropical Agriculture (IITA). Breeders have developed varieties that can thrive in low soil fertility conditions, along with resistance to other stresses such as pests and drought. The project has seen the adoption of new maize varieties by more than six million households across 13 countries, with some farms increasing yields by over 150 per cent.
Our soils depend on breeding for the future. Breeding is showing real results for improving yields, delivering better food, and increasing smallholder incomes. But its impact on ecosystems could go either way. With the right investments in relationships, good research practices, and delivering varieties matched to particular soil conditions, we can breed for the present and for the future.
It is time to invest in both crop breeding and soil management — as one vital package of innovations.
The active involvement of partners in the co-design of project and capacity building activities is key to the success of the Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) project, led by the International Maize and Wheat Improvement Center (CIMMYT). To that end, the AGG Regional Collaborative Breeding and Testing Networks launched with virtual meetings on September 14 and 15 for southern African partners, and October 28 and November 2 for eastern African partners.
In addition, the AGG team collaborated with researchers from the Excellence in Breeding (EiB) Platform on a number of capacity development webinars in October and November, on topics including Continuous Improvement for breeding processes, programs and products, enhancing and measuring genetic gain in crop breeding, and a three-webinar series on statistical analysis for plant breeders with CIMMYT’s Biometrics and Statistics Unit.
These training events and regional meetings provided opportunities for well over 100 breeders from CIMMYT, national agricultural research systems (NARS) and seed companies to refresh their capacities to improve genetic gains, and to collectively review and discuss upcoming project activities, current issues of interest, and broader project objectives within their current regional context.
Several themes of importance to partners emerged during the network virtual meetings, for attention in future AGG activities and capacity development work.
Gender inclusion and the impact of COVID-19
Ugandan partners, including Godfrey Asea, director of the National Crops Resources Research Institute at Uganda’s National Agricultural Research Organization, and Josephine Okot, founder and managing director of Victoria Seeds, applauded the project’s emphasis on inclusion of women’s knowledge and preferences in breeding programs.
“We notice that this time there is a lot of focus on gender-inclusiveness,” remarked Asea. “I can tell you there is need for enhanced capacity building for both the private sector and research in proper gender inclusion.”
They also noted the importance of building local capacity, not just for food security but also for other value chain items like raw materials. “COVID-19 has demonstrated to all policy-makers that we cannot depend on the global supply chains,” said Okot. “How can we leverage this project if, for instance, some private sector actors want to [know] the appropriate protein-content maize for, say, animal feed?”
Demand for knowledge
NARS members in Tanzania requested increased support on how to measure or assess genetic gains, especially at the national level, to allow them to establish a baseline upon which genetic gains would be pegged for the project lifecycle.
With statistics an essential element to plant breeding — from analyzing yield trials to ranking varieties — the webinar series in Statistical Analysis for Plant Breeders was a first step towards meeting these capacity development needs.
“The idea of this webinar series was to share insights on how we can improve the breeding plans using statistical methods in an effective way,” said Juan Burgueño, the head of CIMMYT’s Biometrics and Statistics Unit. “The training offered both theory and hands-on experience using open-access software.”
Reaching farmers
Looking beyond breeding, meeting participants also discussed how to improve access and adoption of improved varieties among farmers.
“For a large country such as Tanzania, it is at times very hard to reach the farmers,” said Zabron Mbwaga, managing director of the Tanzania-based Beula Seed Company and Consultancy Limited. “We may have a lot of seed in the store, but how to get the farmers to adopt the newer varieties is quite difficult. This is more so when farmers tend to stick to varieties which they know well and are always reluctant to adopt the new varieties,” he explained.
“We need to put in a lot of effort to set up demonstration farms and enhance other awareness-raising activities such as radio programs so that farmers can know about the new varieties.”
This interest in working with smallholder farmers along the entire value chain was echoed by partners in southern Africa.
“Through this project, we would like to explore ways of collaborating along the whole value chain — as the Agriculture Research Council, other partners and small to medium enterprises — to make it an effective chain,” said Kingstone Mashingaidze, senior research manager at the South Africa Agricultural Research Council. “By planning together, we can identify best-fits for all activities in the value chain and ultimately benefit the smallholder farmers.”
About the AGG Regional Collaborative Breeding and Testing Networks
The AGG Regional Collaborative Breeding and Testing Networks aim to improve breeding efficiencies among partners by enabling the use of modern tools and approaches and enriching the existing network of research organizations, public and private seed companies, farmers’ organizations, non-governmental organizations and community-based organizations. It is expected that these networks will lead to increased efficiency and communications across the partnership network and within countries, improved sharing of best practices and protocols, and increased collective ownership of products for accelerated variety development and turnover.
The virtual meetings for the Regional Collaborative Breeding and Testing Network for southern Africa convened participants from Malawi, Mozambique, South Africa, Zambia and Zimbabwe, while meetings for eastern Africa had participants from Ethiopia, Kenya, Tanzania and Uganda.
AGG communications staff Joshua Masinde and Shiela Chikulo contributed to this story.
Since the earliest days of global wheat breeding at the International Maize and Wheat Improvement Center (CIMMYT), breeders have made their crossing selections to meet farmers’ requirements in specific environments throughout the world’s wheat-growing regions.
To streamline and make this trait selection process consistent, in the 1970s CIMMYT breeders developed 15 mega-environments — sets of farming, climatic, weather, and geographic conditions to use as profiles for testing their varieties.
They took this a step further in the 1980s by developing sets of profiles for their varieties with common characteristics in current — and projected — climatic, soil and hydrological characteristics as well as socioeconomic features such as end-use quality and agronomic practices.
In newly presented research, CIMMYT wheat scientist Leo Crespo has taken another look at these mega-environments in the form of target population of environments (TPE) — specifically the ones that fall in the bread basket wheat production area of India — to create more nuanced definitions based on updated underlying conditions and desired traits.
Using meteorological and soil data, along with information about farmers’ practices in each region and more advanced analytical methods, Crespo defined three new specific TPEs for the region:
These TPEs encompass more than 28 million hectares, equivalent to more than 97% of India’s total wheat production area.
“While the mega-environments can be broad and transcontinental, we defined the TPE at a more regional level,” said Crespo. “In fact, two of our new TPEs — the NWPZ (TPE1) and part of the NEPZ (TPE2) — have distinct climate and soil characteristics, but they both fall under the same mega-environment: ME1.”
Comparing international environments
Crespo later cross-checked these TPEs with the testing environments that CIMMYT wheat breeders use in the research station in Obregon, in Mexico’s Sonora Valley.
Obregon has long been valued by wheat breeders worldwide for its unique capacity to simulate many wheat growing conditions. Wheat grown in the various testing environments replicate in Obregon — known as selection environments (SEs) — goes through an arduous testing process including testing in other agroeconomic zones and undergoing pest and disease infestations to demonstrate its resilience.
This process, though intensive, is much cheaper and more efficient than testing each potential new wheat line in every major wheat growing area. That is why it is so important to verify that the decisions made in Obregon are the right ones for farmers in the diverse growing areas of the world.
Crespo used data from one of CIMMYT’s global wheat trials, the Elite Spring Wheat Yield Trials (ESWYT), to estimate the genetic correlation between the TPEs and in Obregon, selection response indicators and performance prediction. He found that wheat lines that perform well in the Obregon selection environments are very likely to display high performance in the TPEs he defined in India.
“Our results provide evidence that the selection environments in CIMMYT’s Obregon research station correlate with international sites, and this has led to high genetic gains in targeted regions,” explained Crespo.
“We can achieve even greater gains by targeting selections for farmers in the TPEs and improving the testing in those TPEs, along with the high-quality evaluations from the selection environment.”
These findings confirming the relationship between the selection environments and farmers’ fields in one of the world’s largest wheat growing regions allow CIMMYT to realize its mission to deliver superior wheat germplasm to national partners for their breeding programs, or for direct release as varieties for farmers throughout the world.
Watch Leo Crespo’s full presentation at the BGRI Technical Workshop.
To adequately confront rapidly changing plant pests and diseases and safeguard food security for a growing population, breeders — in collaboration with their partners — have to keep testing and applying new breeding methods to deliver resilient seed varieties at a much faster rate using minimal resources. Molecular markers are essential in this regard and are helping to accelerate genetic gains and deliver better seed to smallholders across sub-Saharan Africa in a much shorter timeframe.
Progress made so far in molecular plant breeding, genetics, genomic selection and genome editing has contributed to a deeper understanding on the role of molecular markers and greatly complemented breeding strategies. However, phenotyping remains the single most costly process in plant breeding, thus limiting options to increase the size of breeding programs.
Application of molecular markers increases the ability to predict and select the best performing lines and hybrids, prior to selection in the field. “This enables breeders to expand the size of a breeding program or the populations they work on using the same amount of resources,” says Manje Gowda, a maize molecular breeder at the International Maize and Wheat Improvement Center (CIMMYT).
“There are three stages in the use of molecular markers: discovery, validation and deployment,” he explains. “At the discovery phase, the objective is to find molecular markers associated or tightly linked with the trait of interest, while also assessing whether the trait is more complex or easier to handle with few markers for selection.”
The molecular markers identified at the discovery stage are validated in independent bi-parental or backcross populations, and the marker trait associations — which are consistent across different genetic backgrounds and diverse environments — are then moved to the deployment stage. Here, they are considered for use in breeding either as part of marker assisted selection or forward breeding, marker assisted back crossing and marker assisted recurrent selection.
Screening for resistance markers
CIMMYT scientists have discovered several marker trait associations for crop diseases including maize lethal necrosis (MLN), maize streak virus (MSV), corn rust and turcicum leaf blight. All these trait-associated markers have been validated in biparental populations.
For MLN, after screening several thousands of lines, researchers identified a few with resistance against the viral disease, namely KS23-5 and KS23-6. These lines were obtained from synthetic populations developed by Kasetsart University in Thailand and serve as trait donors. Researchers were able to use these as part of forward breeding, producing doubled haploid (DH) lines by using KS23-6 as one parent and screening for the presence of MLN resistance genes.
“This screening helps eliminate the lines that may carry susceptible genes, without having to phenotype them under artificial inoculation,” says Gowda. “These markers are also available to all partners to screen for MLN resistance, thereby saving on costs related to phenotyping.”
Scientists also used these MLN resistance markers to introgress the MLN resistance into several elite lines that are highly susceptible to the disease but have other desirable traits such as high grain yield and drought tolerance. The marker-assisted backcrossing technique was used to obtain MLN resistance from the KS23-5 and KS23-6 donor lines. This process involves crossing an elite, commercial line — as a recurrent parent in the case of CIMMYT elite lines — with a donor parent line (KS23) with MLN resistance. These were then backcrossed over two to three cycles to improve the elite line carrying MLN resistance genes. In the past three years, more than 50 lines have been introgressed with the MLN resistance gene from KS23-6 donor line.
An impetus to breeding programs
“The work Manje Gowda has been carrying out is particularly important in that it has successfully moved from discovery of valuable markers and proof-of-concept experiments to scalable breeding methods which are being used effectively,” says CIMMYT Trait Pipeline and Upstream Research Coordinator Mike Olsen. “Enabling routine implementation of molecular markers to increase selection efficiency of breeding programs in the context of African maize improvement is quite impactful.”
At CIMMYT, Gowda’s team applied genomic selection at the early stage of testing the breeding pipeline for different product profiles. “The objective was to testcross and phenotype 50% of the Stage One hybrids and predict the performance of remaining 50% of the hybrids using molecular markers,” Gowda explains.
The team have applied this strategy successfully each year since 2017, and the results of this experiment show that selection efficiency is the same as when using phenotypic selection, but using only 32% of the resources. From 2021 onwards, the aim is to use the previous year’s Stage One phenotypic and genotypic data to predict 100% of the lines. This will not only save the time but improve efficiency and resource use. The previous three-year Stage One historical data is helping to reduce the phenotyping of lines from 50% to 15%, with an increase in saving resources of up to 50%.
For the commercial seed sector, integrating molecular marker-based quality control measures can help deploy high-quality seeds, an important factor for increasing crop yields. In sub-Saharan Africa, awareness on marker-based quality has improved due to increased scientist and breeder trainings at national agricultural research systems (NARS), seed companies and national plant protection organizations, as well as regulators and policymakers.
Currently, many NARS and private sector partners are making it mandatory to apply marker-based quality control to maintain high-quality seeds. Since NARS and small- and medium-sized seed companies’ breeding programs are smaller, CIMMYT is coordinating the collection of samples from different partners for submission to service providers for quality control purposes. CIMMYT staff are also helping to analyze quality control data and interpret results to sharing with partners for decision-making. For the sustainability of this process, CIMMYT is training NARS partners on quality control, from sample collection to data analyses and interpretation, and this will support them to work independently and produce high-quality seed.
Such breeding improvements have become indispensable in supporting maize breeding programs in the public and private sectors to develop and deliver improved maize varieties to smallholder farmers across sub-Saharan Africa.
Wheat scientists in the Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) project, led by the International Maize and Wheat Improvement Center (CIMMYT), presented a range of new research at the 2020 Borlaug Global Rust Initiative (BGRI) Technical Workshop in October, highlighting progress in spring wheat breeding, disease screening and surveillance and the use of novel genomic, physiological tools to support genetic gains.
Sridhar Bhavani, CIMMYT senior scientist and head of Rust Pathology and Molecular Genetics, delivered a keynote presentation on a “Decade of Stem Rust Phenotyping Network: Opportunities, Challenges and Way Forward,” highlighting the importance of the international stem rust phenotyping platforms established with national partners in Ethiopia and Kenya at the Ethiopian Institute for Agricultural Research station in Debre Zeit, and the Kenya Agricultural and Livestock Research Organization station in Njoro, respectively. These platforms support global wheat breeding, genetic characterization and pre-breeding, surveillance and varietal release, and will continue to be an important mechanism for delivering high performing material into farmers’ fields.
CIMMYT wheat breeder Suchismita Mondal chaired a session on breeding technologies, drawing on her expertise leading the trait delivery pipeline in AGG (including rapid generation cycling and speed breeding). She led a lively Q&A on the potential for genomics and data-driven approaches to support breeding.
In the session, CIMMYT Associate Scientist and wheat breeder Philomin Juliana presented a “Retrospective analysis of CIMMYT’s strategies to achieve genetic gain and perspectives on integrating genomic selection for grain yield in bread wheat,” demonstrating that phenotypic selection — making breeding selections based on physically identifiable traits — has helped increase the proportion of genes associated with grain yield in CIMMYT’s globally distributed spring wheat varieties. Her work demonstrates the efficiency of indirect selection for yield in CIMMYT’s Obregon research station, and the potential of genomic selection, particularly when incorporating environmental effects.
The use of Obregon as a selection environment was further explored by CIMMYT wheat breeder Leo Crespo presenting “Definition of target population of environments in India and their prediction with CIMMYT’s international nurseries.” This work confirms Obregon’s relevance as an effective testing site, allowing the selection of superior germplasm under distinct management conditions that correlate with large agroecological zones for wheat production in India. Similar analyses will be conducted in AGG with the support of the CGIAR Excellence in Breeding Platform to optimize selection conditions for eastern Africa.
Supporting future genetic gains
CIMMYT’s Head of Global Wheat Improvement Ravi Singh presented “Genetic gain for grain yield and key traits in CIMMYT spring wheat germplasm — progress, challenges and prospects,” highlighting the International Wheat Improvement Network as an important source of new wheat varieties globally. He described progress on the implementation of genomic selection and the use of state of the art tools to collect precise plant trait information, known as high-throughput phenotyping (HTP), in CIMMYT wheat breeding.
With partners, he is now conducting both genotyping (measuring the genetic traits of a plant) and phenotyping for all entries in the earliest stages of yield trials in Mexico. In addition, his team has succeeded in phenotyping a large set of elite lines at multiple field sites across South Asia. Looking forward, they aim to shorten generation advancement time, improve the parental selection for “recycling” (re-using parents in breeding), and adding new desirable traits into the pipeline for breeding improved varieties.
Following on from Ravi’s presentation, CIMMYT scientist Margaret Krause highlighted progress in HTP in her talk on “High-Throughput Phenotyping for Indirect Selection on Wheat Grain Yield at the Early-generation Seed-limited Stage in Breeding Programs.” This work highlights the potential of drones to capture highly detailed and accurate trait data, known as aerial phenotyping, to improve selection at the early-generation, seed-limited stages of wheat breeding programs.
This kind of physiological understanding will support future phenotyping and selection accuracy, as seen in the work that CIMMYT scientist Carolina Rivera shared on “Estimating organ contribution to grain-filling and potential for source up-regulation in wheat cultivars with contrasting source-sink balance.” Her research shows that a plant’s production of biomass is highly associated with yield under heat stress and that it is possible to achieve greater physiological resolution of the interaction between traits and environment to deliver new selection targets for breeding.
Overall, the talks by AGG scientists demonstrated tremendous progress in spring wheat breeding at CIMMYT and highlighted the importance of new tools and technologies to support future genetic gains.
All presentations can be found on the BGRI Workshop 2020 website.
The Borlaug Global Rust Initiative is an international community of hunger fighters committed to sharing knowledge, training the next generation of scientists, and engaging with farmers for a prosperous and wheat-secure world. The BGRI is funded in part through the Delivering Genetic Gain in Wheat (DGGW) project from the Bill & Melinda Gates Foundation and the UK Foreign, Commonwealth & Development Office.
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), HarvestPlus, Kansas 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 Government of Ethiopia has consistently prioritized agriculture and sees it as a core component of the country’s growth. However, despite considerable efforts to improve productivity, poor management of soil health and fertility has been an ongoing constraint. This is mainly due to a lack of comprehensive site-and context-specific soil health and fertility management recommendations and dissemination approaches targeted to specific needs.
The government envisions a balanced soil health and fertility system that helps farmers cultivate and maintain high-quality and fertile soils through the promotion of appropriate soil-management techniques, provision of required inputs, and facilitation of appropriate enablers, including knowledge and finance.
So far, a plethora of different research-for-development activities have been carried out in support of this effort, including the introduction of tools which provide location-specific fertilizer recommendations. For example, researchers on the Taking Maize Agronomy to Scale in Africa (TAMASA) project, led by the International Maize and Wheat Improvement Center (CIMMYT), have created locally calibrated versions of Nutrient Expert® (NE) — a tool for generating fertilizer recommendations — for maize farmers in Ethiopia, Nigeria and Tanzania.
Nutrient Expert® is only one of the many fertilizer recommendation tools which have been developed in recent years covering different levels of applicability and accuracy across spatial scales and users, including smallholder farmers, extension agents and national researchers. However, in order to make efficient use of all the resources available in Ethiopia, there is a need to systematically evaluate the merits of each tool for different scales and use cases. To jump start this process, researchers from the TAMASA project commissioned an assessment of the tools and frameworks that have been developed, adapted and promoted in the country, and how they compare with one another for different use-cases. Seven tools were assessed, including Nutrient Expert®, the Ethiopian Soil Information System (EthioSIS) and RiceAdvice.
For each of these, the research team asked determined how the tool is currently being implemented — for example, as an app or as a generic set of steps for recommendation generation — and its data requirements, how robust the estimates are, how complicated the interface is, how easy it is to use, the conditions under which it performs well, and the spatial scale at which it works best.
Combining efforts and information
The results of this initial assessment indicate that the type of main user and the scale at which decisions are made varied from tool to tool. In addition, most of the tools considered have interactive interfaces and several — including Nutrient Expert® and RiceAdvice — have IT based platforms to automate the optimization of fertilizer recommendations and/or analyze profit. However, the source codes for all the IT based platforms and tools are inaccessible to end-users. This means that if further evaluation and improvements are to be made, there should be a means of collaborating with developers to share the back-end information, such as site-specific response curves and source codes.
Because most of the tools take different approaches to making fertilizer application site-specific, each of them renders unique strengths and trade-offs. For example, Nutrient Expert® may be considered strong in its approach of downscaling regionally calibrated responses to field level recommendations based on a few site-specific responses from farmers. By contrast, its calibration requires intensive data from nutrient omission trials and advice provision is time consuming.
Overall, the use of all the Site-Specific Decision-Support Tools (SSDST) has resulted in improved grain yields compared to when farmers use traditional practices, and this is consistent across all crops. On average, use of Nutrient Expert® improved maize, rice and wheat yields by 5.9%, 8.1% and 4.9%, respectively. Similarly, the use of RiceAdvice resulted in a 21.8% yield advantage.
The assessment shows that some of the tools are useful because of their applicability at local level by development agents, while others are good because of the data used to develop and validate them. However, in order to benefit the agricultural system in Ethiopia from the perspective of reliable fertilizer-use advisory, there is a need to develop a platform that combines the merits of all available tools. To achieve this, it has been suggested that the institutions who developed the individual tools join forces to combine efforts and information, including background data and source codes for IT based tools.
While the COVID-19 pandemic has disrupted efforts to convene discussions around this work, CIMMYT has and will continue to play an active advocacy role in supporting collaborative efforts to inform evidence-based reforms to fertilizer recommendations and other agronomic advice in Ethiopia and the wider region. CIMMYT is currently undertaking a more rigorous evaluation of these tools and frameworks as a follow up on the initial stocktaking activity.
The current COVID-19 pandemic — and associated measures to reduce its spread — is projected to increase extreme poverty by 20%, with the largest increase in sub-Saharan Africa, where 80 million more people would join the ranks of the extreme poor. Accelerating the process of delivering high-quality, climate resilient and nutritionally enriched maize seed is now more critical than ever.However, developing these varieties is not a rapid or cheap process. Over the course of five years, researchers on the Stress Tolerant Maize for Africa (STMA) project developed a range of tools and technologies to reduce the overall cost of producing a new high yielding, stress tolerant hybrids for smallholder farmers in the region.
Maize breeding starts with crossing two parents and essentially ends after testing their great-great-great-great grandchildren in as many locations as possible. This allows plant breeders to identify the new varieties which will perform well in the conditions faced by their target beneficiaries — in the case of STMA, smallholder farmers in Africa. In other parts of the world, new tools and technologies are routinely added to breeding programs to help reduce the cost and time it takes to produce new varieties.
Scientists on the STMA project focused on testing and scaling new tools specifically for maize breeding programs in sub-Saharan Africa and began by taking a closer look at the most expensive part of the breeding process: phenotyping or collecting precise information on plant traits.
“Within a breeding program, phenotyping is the single most costly step,” explains CIMMYT molecular breeder Manje Gowda. “Molecular technologies provide opportunities to reduce this cost.” The research team tested two methods to speed up this step and make it more cost efficient: forward breeding and genomic selection.
Speeding up a long and costly process
Two important traits maize breeders look for in their plant progeny are susceptibility for two key maize diseases: maize streak virus (MSV) and maize lethal necrosis (MLN). In traditional breeding, breeders must extensively test lines in the field for their susceptibility to these diseases, and then remove them before the next round of crossing. This carries a significant cost.
Using a process called forward breeding, scientists can screen for DNA markers known to be associated with susceptibility to these diseases. This allows breeders to identify lines vulnerable to these diseases and remove them before field testing.
Scientists on the STMA project applied this approach in CIMMYT breeding programs in eastern and southern Africa over the past four years, saving an estimated $300,000 in field costs. Under the AGG project, research will now focus on applying forward breeding to identify susceptibility for another fast-spreading maize pest, fall armyworm, as well as extending use of this method in partners’ breeding programs.
Forward breeding is ideal for “simple” traits which are controlled by a few genes. However, other desired traits, such as tolerance to drought and low nitrogen stress, are genetically complex. Many genes control these traits, with each gene only contributing a little towards overall stress tolerance.
In this case, a technology called genomic selection can be of service. Genomic selection estimates the performance, or breeding value, of a line based largely on genetic information. Genomic selection uses more than 5,000 DNA markers, without the need for precise information about what traits these markers control. The method is ideal for complicated traits such as drought and low nitrogen stress tolerance, where hundreds of small effect genes together largely control how a plant grows under these stresses.
CIMMYT scientists used this technology to select and advance lines for drought tolerance. They then tested these lines and compared their performance in the field to lines selected conventionally. They found that the two sets of resulting hybrid varieties — those advanced using genomic selection and those advanced in the field — showed the same grain yield under drought stress. However, genomic selection only required phenotyping half the lines, achieving the same outcome with half the budget.
Innovations in the field
While DNA technology is reducing the need for extensive field phenotyping, research is also underway to reduce the cost of the remaining necessary phenotyping in the field.
Typically, many traits — such as plant height or leaf drying under drought stress — are measured by hand, using the labor of large teams of people. For example, plant and ear height is traditionally measured by a team of two using a meter stick.
Mainasarra Zaman-Allah, a CIMMYT abiotic stress phenotyping specialist based in Zimbabwe, has been developing faster, more accurate ways to measure these traits. He implemented the use of a small laser sensor to measure plant and ear height which only requires one person. This simple yet cost effective tool has reduced the cost of measuring these traits by almost 60%. Similarly, using a UAV-based platform has reduced the cost of measuring a trait known as canopy senescence — leaf drying associated with drought susceptibility —by over 65%.
The identification of plants which are tolerant to key diseases has traditionally involved scoring the severity of disease in each plot visually, but walking through hundreds of plots daily can lead to errors in human judgement. To combat this, CIMMYT biotic stress phenotyping specialist LM Suresh collaborated with Jose Luis Araus and Shawn Kefauver, scientists at the University of Barcelona, Spain, to develop image analysis software that can quantify disease severity, thereby avoiding problems associated with unintentional human bias.
Plant breeders need uniform, or homozygous, lines for selection. With conventional plant breeding this is difficult: no matter how many times you cross a line, a small amount of DNA will remain heterozygous — having two different alleles of a particular gene — and reduce accuracy in line selection.
A technology called doubled haploid allows breeders to develop homozygous lines within two seasons. While this technology has been used in temperate maize breeding programs since the 1990s, it was not available for tropical environments until 10 years ago. In 2013, thanks to joint work with Kenyan partners at the CIMMYT Doubled Haploid facility in Kiboko, this technology was made available to African breeding programs. Now Vijay Chaikam, a CIMMYT doubled haploid specialist based in Kenya, is working towards reducing the cost of this technology as well.
The efforts begun by the STMA research team is now continuing under the Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) project. As this work is carried forward, the next crucial step is ensuring that the next generation of African maize breeders have access to these technologies and tools.
“Improving national breeding programs will really drive success in raising maize yields in the stress prone environments faced by many farmers in our target countries,” says Mike Olsen, CIMMYT’s upstream trait pipeline coordinator. Under AGG, in collaboration with the CGIAR Excellence in Breeding Program, these tools will be scaled out.