Feed the Future Innovation Lab for Legume Systems Research

Cowpea, a highly nutritious legume crop vitally important to food security in the Sudano-Sahel, West Africa, especially for women and children, complements dietary cereals. However, typical smallholder farmer yields are 10-20% of yield potential, mainly due to insect pests, pathogens, parasites and drought.

The project focused on Ghana, Senegal and Burkina Faso, three countries in the West Africa cowpea production region, chosen on the basis of: 1) alignment with USAID country foci, with Ghana and Senegal being Feed the Future target countries and Burkina Faso a Feed the Future aligned country, with Zones of Influence impacted by cowpea production dynamics, either directly through local cowpea production increases (northern Ghana, central and northern Burkina Faso) or secondarily via country-wide cowpea systems enhancements (Senegal); 2) representation of the primary cowpea production agro-ecologies within each of the countries, and providing a broader regional representation of West Africa cowpea production systems; and 3) mature host country-UCR collaborative research and breeding partnerships that provided a robust project efficiency, productivity and management framework.

Cowpea downstream breeding utilized previously discovered single nucleotide polymorphism (SNP) marker haplotypes linked to target traits. A suite of marker-trait pairs was used in improvement of elite varieties and lines through indirect selection for enhanced variety releases. Tolerance/resistance to aphids, thrips, Macrophomina, and Striga, together with drought tolerance and preferred grain quality (large seed, rough seed-coat for quicker cooking time, plus seed color specific to host country target region market preference for white, or light cream with brown-eye or black-eye, or brown) were phenotypes chosen to improve six current popular varieties, and in selecting breeding population lines for market-driven preferred grain types.

Improvement of elite varieties and lines was conducted using three sets of cowpea breeding stocks. These included three breeder-selected current elite varieties in each host country; elite 8-parent multi-parent advanced generation intercross (MAGIC) lines and a set of new super-MAGIC (spMAGIC) lines developed by intercrossing selected MAGIC population lines carrying high positive allele content of target traits; and elite marker-assisted recurrent selection (MARS) lines developed in Burkina Faso and Nigeria. Field and greenhouse phenotyping in Ghana, Senegal and Burkina Faso was matched with SNP marker high-throughput genotyping to select for both the target traits (foreground selection) and for recurrent background recovery (background selection) in backcrossing cycles. Near-release lines were tested regionally to broaden release potential. Formal release applications were prepared and submitted by the host country co-PI in each country.

In California, cowpea dry grain novel market classes of breeding lines were advanced, utilizing marker resources and breeding lines for overlapping trait targets with the West Africa targets. This project leveraged funding from the California Dry Bean Advisory Board to produce one improved blackeye dry-grain cowpea variety (‘California Blackeye 77’ or ‘CB77’) and advanced breeding lines for fresh market and canning, in support of the US dry bean industry.

Primary capacity building in each of the host countries was achieved by graduate degree training in cowpea breeding and genetics, coupled with continuous short-term training of host country scientists in molecular breeding. The outputs and associated capacity building contributed to Feed the Future priorities to increase pulse productivity via yield gain, thereby promoting dietary nutritional value and the livelihoods of women and youth, and resilience by increased household incomes.

Read the full report here