IITA and partners in the Netherlands and the United States are developing genomic tools that will facilitate the development of improved cowpea varieties with traits such as drought tolerance.
An IITA-Lukas Brader Postgraduate Fellow, Eugene Agbicodo, who carried out the genetic analysis of drought tolerance in cowpea and subsequently constructed a linkage map of the crop, identified portions on the cowpea genome where genes that have effects on drought tolerance and resistance to bacterial blight could be located.
His findings, a landmark in marker-assisted selection in cowpea improvement, will help shorten the plant breeding process.
Similar work has been reported by researchers at the University of California, Riverside, and researchers at the two institutions are comparing notes on the outcomes of their research to see areas of agreement and possible collaboration, according to Christian Fatokun, Cowpea Breeder, who supervised Agbicodo’s genomic mapping work at IITA.
â€œIf both parties are able to find areas of agreement or concurrence, such areas of the genome would be of immense benefit when marker-assisted selection is applied in cowpea breeding. So what will normally take about 10 years to accomplish could be done in three years or even less,â€ he said.
With about 70% of world cowpea grown in the savanna region of Africa, the protein-rich legume provides not only incomes but also improves the health of its consumers. However, cowpea faces several production constraints, among which are diseases, insect pests, parasitic weeds such as Striga, and drought which is becoming increasingly important in the cowpea-producing zones of sub-Saharan Africa.
Agbicodo phenotyped and genotyped a set of cowpea recombinant inbred lines generated at IITA in Ibadan. Phenotyping was carried out in Ibadan and Kano, Nigeria, while the genotyping was carried out at the University of Wageningen, The Netherlands.
Consequently, he constructed a cowpea genetic linkage map using the data obtained from genotyping and phenotyping. The linkage map showed molecular markers that defined quantitative trait loci (QTLs) with effects on drought tolerance and resistance to bacterial blight among others.