Harish Gandhi is a Breeding Lead for Dryland Legumes and Cereals in CIMMYT’s Genetic Resources program in Kenya. He is a transformative plant breeding and genetics professional, with more than 15 years experience of driving genetic gains, building effective teams, and pioneering innovative research and development.
Spot blotch, a major biotic stress challenging bread wheat production is caused by the fungus Bipolaris sorokiniana. In a new study, scientists from the International Maize and Wheat Improvement Center (CIMMYT) evaluate genomic and index-based selection to select for spot blotch resistance quickly and accurately in wheat lines. The former approach facilitates selecting for spot blotch resistance, and the latter for spot blotch resistance, heading and plant height.
Genomic selection
The authors leveraged genotyping data and extensive spot blotch phenotyping data from Mexico and collaborating partners in Bangladesh and India to evaluate genomic selection, which is a promising genomic breeding strategy for spot blotch resistance. Using genomic selection for selecting lines that have not been phenotyped can reduce the breeding cycle time and cost, increase the selection intensity, and subsequently increase the rate of genetic gain.
Two scenarios were tested for predicting spot blotch: fixed effects model (less than 100 molecular markers associated with spot blotch) and genomic prediction (over 7,000 markers across the wheat genome). The clear winner was genomic prediction which was on average 177.6% more accurate than the fixed effects model, as spot blotch resistance in advanced CIMMYT wheat breeding lines is controlled by many genes of small effects.
“This finding applies to other spot blotch resistant loci too, as very few of them have shown big effects, and the advantage of genomic prediction over the fixed effects model is tremendous”, confirmed Xinyao He, Wheat Pathologist and Geneticist at CIMMYT.
The authors have also evaluated genomic prediction in different populations, including breeding lines and sister lines that share one or two parents.
Index selection
One of the key problems faced by wheat breeders in selecting for spot blotch resistance is identifying lines that are genetically resistant to spot blotch versus those that escape and exhibit less disease by being late and tall. “The latter, unfortunately, is often the case in South Asia”, explained Pawan Singh, Head of Wheat Pathology at CIMMYT.
A potential solution to this problem is the use of selection indices that can make it easier for breeders to select individuals based on their ranking or predicted net genetic merit for multiple traits. Hence, this study reports the first successful evaluation of the linear phenotypic selection index and Eigen selection index method to simultaneously select for spot blotch resistance using the phenotype and genomic-estimated breeding values, heading and height.
This study demonstrates the prospects of integrating genomic selection and index-based selection with field based phenotypic selection for resistance in spot blotch in breeding programs.
Read the full study:
Genomic selection for spot blotch in bread wheat breeding panels, full-sibs and half-sibs and index-based selection for spot blotch, heading and plant height
Cover photo: Bipolaris sorokiniana, the fungus causing spot blotch in wheat. (Photo: Xinyao He and Pawan Singh/CIMMYT)
Spot blotch, caused by the fungus Biopolaris sorokiniana poses a serious threat to bread wheat production in warm and humid wheat-growing regions globally, affecting more than 25 million hectares and resulting in huge yield losses.
Chemical control approaches, including seed treatment and fungicides, have provided acceptable spot blotch control. However, their use is unaffordable to resource-poor farmers and poses a hazard to health and the environment. In addition, “abiotic stresses like heat and drought that are widely prevalent in South Asia compound the problem, making varietal genetic resistance the last resort of farmers to combat this disease,” according to Pawan Singh, Head of Wheat Pathology at the International Maize and Wheat Improvement Center (CIMMYT). Therefore, one of CIMMYT’s wheat research focus areas is developing wheat varieties that carry genetic resistance to the disease.
Previously, only four spot blotch resistance genes in bread wheat had been identified. Through a new study, CIMMYT scientists have identified novel genomic regions associated with spot blotch resistance using the genome-wide association mapping approach with 6,736 advanced breeding lines from different years (2013 to 2020), evaluated at CIMMYT’s spot blotch screening platform in Agua Fría, in Mexico’s state of Morelos.
The study’s results are positive and confirmed that:
“Considering the persistent threat of spot blotch to resource-poor farmers in South Asia, further research and breeding efforts to improve genetic resistance to the disease, identify novel sources of resistance by screening different germplasm, and selecting for genomic regions with minor effects using selection tools like genomic selection is essential,” explained Philomin Juliana, Molecular Breeder and Quantitative Geneticist at CIMMYT.
Read the full study:
Genome-Wide Association Mapping Indicates Quantitative Genetic Control of Spot Blotch Resistance in Bread Wheat and the Favorable Effects of Some Spot Blotch Loci on Grain Yield
Cover photo: Researchers evaluate wheat for spot blotch at CIMMYT’s experimental station in Agua Fría, Jiutepec, Morelos state, Mexico. (Photo: Xinyao He and Pawan Singh/CIMMYT)
In this op-ed, Harvard Professor Gabriela Soto Laveaga stresses the importance of tackling hunger as more than a technical problem to be addressed through scientific advancement alone, praising CGIAR for its community-centered & inclusive approach to food systems amid the climate crisis.
Read more: https://www.washingtonpost.com/outlook/2021/11/22/throwing-money-problem-wont-solve-world-hunger/
Dryland Crops, formerly known as the Accelerated Varietal Improvement and Seed Systems in Africa (AVISA) project, aims to improve the livelihoods of small-scale producers and consumers of sorghum, millet, groundnut, cowpea and bean. Project partners focus on improving the breeding and seed systems of these crops in their key geographies in Burkina Faso, Ethiopia, Ghana, Mali, Nigeria, Tanzania and Uganda. Other crops receiving growing attention in the project include finger millet, pigeon pea and chickpea.
Although significant adoption of improved seed of dryland cereals and legume crops in Africa has been reported, its overall use remains low. There is a growing interest in these crops, particularly because of their resilience to climate-change; however, the seed sector is constrained by lack of product information, dearth of knowledge of the size and scale of the business opportunity, and inadequate access to early generation seed.
Dryland Crops will address these constraints by contributing to the establishment of robust systems that:
The aspiration is to codevelop, validate by co-implementation, and continuously improve with partners research-to-farm-to-consumer models that achieve positive impacts on farmers’ livelihoods and consumers’ wellbeing.
The Alliance of Bioversity and CIAT and IITA will lead initiatives for common bean and cowpea, respectively. For sorghum, pearl millet and groundnut breeding, CIMMYT will design programs that support crop improvement networks, including CGIAR and national agricultural research systems, and incorporate best approaches, principles, and tools, particularly those availed through the Excellence in Breeding (EiB) platform.
The project is committed to gender equity as a guiding principle, considering the critical role women play in choosing legume and cereal varieties and seed sources. Women seed entrepreneurs and women-led seed companies will garner special attention for capacity development. Partnerships with actors through the value chain, platforms and demonstrations will ensure women have equal access to improved technologies.
The previous phase of the AVISA project was led by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).
“Can we sustainably feed the nine to ten billion people in our planet in 30 years?” asked Kenneth M. Quinn, president of the World Food Prize Foundation. “This question becomes even more challenging with two current game changers: conflict and climate change.”
Food and agriculture experts met in Des Moines, Iowa, to discuss these issues at the Borlaug Dialogue and awarding of the 2019 World Food Prize.
The focus has shifted over the last few years from food to food systems, now including health and nutrition. “We need an integrated agri-food systems approach for food security, nutrition, nature conservation and human security,” said Bram Govaerts, director of the Integrated Development program at the International Maize and Wheat Improvement Center (CIMMYT).
Speakers agreed that to meet the current challenges of nutrition and climate change, we need a transformation of the global food system. “We have something very positive — this narrative of food system transformation,” said Ruben Echeverría, Director General of the International Center for Tropical Agriculture (CIAT).
In the discussions, speakers highlighted several areas that must be taken into consideration in this transformation.
Food security for peace and development
The theme of this year’s Borlaug Dialogue was “Pax Agricultura: Peace through agriculture.” Panels addressed the interconnected issues of food security, conflict and development.
In the keynote address, USAID Administrator Mark Green issued a call to action and challenged participants “to take on the food and economic insecurity issues that are emerging from this era’s unprecedented levels of displacement and forced migration.” Ambassadors, ministers and development experts gave examples of the interdependence of agriculture and peace, how droughts and floods could create conflict in a country, and how peace can be rebuilt through agriculture.
“Agriculture could root out the insurgency better than anything we did,” said Quinn about the Khmer Rouge surrender in Cambodia, where he served as an ambassador.
In the 1994 genocide in Rwanda, more than 1 million people died in 100 days. Geraldine Mukeshimana, Rwanda’s minister of Agriculture and Animal Resources, explained that in the country’s rebuilding process, all policies centered on agriculture.
“Almost no country has come out of poverty without an agricultural transformation,” said Rodger Voorhies, president of Global Growth and Opportunity at the Bill & Melinda Gates Foundation, in a fireside chat with 2009 World Food Prize Laureate Gebisa Ejera.
Agriculture is vital because without food, we cannot build institutions, processes or economies. “You cannot talk about human rights if you don’t have any food in your stomach,” said Chanthol Sun, Cambodia’s minister of Public Works and Transportation.
Josette Sheeran, president and CEO of Asia Society, echoed this thought, “Nothing is more important to human stability than access to food.”
In a luncheon keynote, Víctor M. Villalobos, Mexico’s Secretary of Agriculture and Rural Development, spoke about CIMMYT, the MasAgro project, and the need to improve food systems and agriculture to fight violence and forced migration. “Agriculture, prosperity and peace are inextricably linked together.”
How to make technological innovations work
Innovations and technology can support a global food system transformation and help to achieve the Sustainable Development Goals.
In a panel on food security in the next decade, speakers shared the agricultural technologies they are excited about: data, gene editing, synthetic biology, data science and precision farming.
Josephine Okot, managing director of Victoria Seeds Ltd said, “We must have mechanization.” She described the fact that Ugandan women farmers still rely on hand tools as a “disgrace to humanity.”
The CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) organized a session where panelists discussed how to realize a transformation in food systems through next generation technologies, highlighting the role regulatory frameworks and policies play in the adoption of new technologies.
Making innovations work is about more than developing the product. “It takes a lot more than just a good seed to get a farmer to use it,” said 2019 World Food Prize Laureate Simon Groot. “It includes good distribution, good marketing, good training, etcetera.”
Technology adoption requires a human emphasis and cultural element in addition to technology development.
Breeding demand-driven crops for all
“The real enemy of farmers is lousy seeds,” said Simon Groot in his speech after receiving the World Food Prize.
CGIAR took the occasion of the World Food Prize to launch a new initiative, Crops to End Hunger. “We are looking for big solutions at CGIAR. Crops to End Hunger is one of them,” said CIMMYT Director General Martin Kropff. This program aims to meet the food, nutrition and income needs of producers and consumers, respond to market demands and increase resilience to challenges of the climate crisis.
“CGIAR released 417 new varieties last year. However, we can do more. Crops to End Hunger will rapidly excel breeding cycles,” said Elwyn Grainger-Jones, CGIAR Executive Director.
Felister Makini, deputy director general for Crops at Kenya Agricultural & Livestock Research Organization (KALRO), explained that focusing on the end users is what will have real impact. “It is important to develop technologies that are demand-driven so that farmers want to grow them and consumers want to buy and eat them.”
In a session to unpack the Crops to End Hunger initiative hosted by Corteva Agriscience and CGIAR, Marco Ferroni, Chair of the CGIAR System Management Board, said that CGIAR is shifting toward a more demand-driven agenda for plant breeding, where markets dictate what the research priorities should be.
“We must consider the human aspect in breeding,” said Michael Quinn, Director of the CGIAR Excellence in Breeding Platform (EiB). “This is where success will really come.”
Panelists discussed gender-conscious breeding, or taking both women and men’s desired traits into account.
The theme of gender was also emphasized by 2019 Norman Borlaug Field Award winner Hale Ann Tufan. She asked the Dialogue attendees to question gender biases and “not only to ‘take it to the farmer’ but take it to all farmers.”
Cover photo: Plenary session of the 2019 Borlaug Dialogue. (Photo: World Food Prize)
Pieter Rutsaert is a markets and value chain specialist with CIMMYT, based in Kenya. His work focuses on the demand side of formal seed systems development in Eastern Africa with special focus on the role of agro-dealers, farmer drivers for varietal turnover and collecting market intelligence data for breeding priorities.
He obtained his MSc in Tropical Natural Resources Management from KULeuven and a PhD from Ghent University in Belgium. Before joining CIMMYT, he worked as a Postdoctoral Fellow at IRRI in the Philippines and as research director for Haystack International, a market research consultancy firm in Belgium.