Researchers to develop improved cowpea varieties
RIVERSIDE – Providing food security, one of the greatest challenges of our time, is a critical goal especially in the developing world, where crop destruction by drought, disease and pest infestation swiftly places millions of lives at risk of hunger.
Scientists at the University of California, Riverside will help meet this challenge by focusing on cowpea, a protein-rich legume crop of immense importance to Africa that complements starchy staple crops such as corn, cassava, sorghum and millets in the diets of millions of Africans. “Our project will develop the key genomic resources that are currently lacking in cowpea,” said Timothy Close, a professor of genetics and a co-principal investigator of the grant, who leads UCR’s cowpea genomics effort. “We will use modern plant breeding approaches that employ new and efficient molecular marker development methodologies.”
Molecular markers are landmarks that help plant scientists identify specific chromosome segments that contain genes of interest. Marker-assisted selection technology allows breeders to more precisely and simultaneously select the best trait combinations (or genes) during the breeding process. The process is not genetic engineering.
“For example, a plant scientist might mark a combination of genes known to increase disease resistance,” Close explained. “Breeders wanting the disease resistance trait then use marker information to identify individuals containing that specific combination of genes. They do so without having to directly measure the trait, which can be difficult and expensive.”
Ehlers, Roberts and Close, along with their project-funded programmers, postdoctoral researchers and students, will develop a detailed genetic ‘roadmap’ of cowpea. In collaboration with their African partners in the national breeding programs of Senegal, Burkina Faso, Cameroon as well as with the International Institute of Tropical Agriculture in Nigeria, they will identify genes linked to important traits such as tolerance to drought and resistance to pests.
The grant to UCR is part of a broader effort by CGIAR’s Generation Challenge Program to improve legumes in sub-Saharan Africa, including beans, groundnuts and chickpeas.
The Generation Challenge Program is a research network that uses plant genetic diversity, advanced genomic science and comparative biology to develop tools and technologies that enable plant breeders in the developing world to produce better crop varieties for resource-poor farmers.
A brief history of UCR’s assistance to Africa through cowpea research:
In the late 1970s, Anthony Hall, a professor emeritus of plant physiology, pioneered work on cowpea at UCR. His research on cowpea physiology contributed to a deeper understanding of cowpea’s adaptation to drought, heat and poor soils. He also led the effort to establish the first genetic map for cowpea.
The research, which is expected to significantly benefit resource-poor African farmers, is being made possible by a three-year grant of nearly $1.7 million to UC Riverside from the Generation Challenge Program of the Consultative Group of International Agricultural Research (CGIAR).
The UCR researchers will apply genomic technology to develop new and improved cowpea cultivars that have tolerance to drought as well as improved resistance to pests and diseases. Due mostly to drought and pests, cowpea yields in Africa oftentimes are less than one fourth their potential yield.
“UCR hosts a collection of 5,000 cowpea varieties from around the world,” said Jeff Ehlers, the principal investigator of the grant and a specialist in the Department of Botany and Plant Sciences with more than 20 years of experience conducting genetic research on cowpea in California and Africa. “These genetically diverse varieties offer a treasure-trove of genes of potential value to breeders seeking to build better cowpea varieties. Because of the grant, we will be able to more efficiently identify genes we can use to develop improved cowpea varieties.”
Cowpea is popular in the southern United States, where it is known as ‘black-eyed peas’ and other names, and consumed as a freshly shelled or dry bean. Immature pods of cowpea are used throughout Asia as a ‘green bean,’ and go by the name ‘yardlong’ or ‘asparagus’ beans.
Produced on more than 30 million acres in hot, drought-prone regions of the tropics and subtropics, cowpea not only provides nutritious food for millions of people and their livestock, but also generates income for rural producers, traders, and small-scale urban food vendors, while at the same time enhancing soil fertility.
“Cowpea yields are traditionally low in Africa, a continent where diets don’t tend to be meat-based,” said Philip Roberts, a professor of nematology and a co-principal investigator of the grant, who currently leads UCR’s Bean/Cowpea Collaborative Research Support Program – a highly successful project, supported by the U.S. Agency for International Development, that has assisted African institutes in developing more than five improved cowpea varieties over the past decade. “The research this new grant will enable has potential to convert cowpea – the poor man’s meat in Africa – into a better cash crop for income generation, thereby increasing living standards.”
UCR researchers have been providing assistance to African scientists since the early 1980s in their work to develop improved cowpea varieties for poor farmers in Africa.
Because it has been largely neglected by the research community, cowpea is called an “orphan crop.” Despite its importance to a significant number of the resource-poor, it has lagged behind other grain legume crops in the development of basic genomic resources and tools needed to implement modern breeding approaches that could alleviate major constraints facing cowpea producers.
The recipient of numerous national and international awards, Hall helped develop and then run an internationally respected long-term project involving scientists from UCR, Senegal and Ghana.
The project trained 13 African scientists (10 doctorates; 3 master of science degrees) and released improved, early maturing cowpea varieties in Senegal (3 varieties: Mouride in 1992, Melakh in 1995, and Yacine in 2004), Ghana (Marfo-Tuya and Aapagbaala, both in 2004) and Sudan (Ein-el-Ghazal in 2003). These varieties have combinations of heat and drought tolerance and improved pest resistance that enhance farmer productivity.
Since 2002, UCR has worked closely with cowpea breeding programs in Burkina Faso, where new candidate varieties developed by UCR are being tested ‘on-farm’; and in Cameroon, where UCR is providing support, materials and guidance to re-establish a discontinued breeding program.
The university also works with cowpea scientists from other African countries through exchanges of cowpea germplasm (or seed stocks) as well as the sharing of information and expertise.
In February 2003, UCR organized a week-long workshop on campus for seven scientists from five West African countries on the use of molecular markers in breeding.