Breeding Cowpea for Resistance to Striga Gesnerioides in the Nigerian Dry Savannas Using Marker Assisted Selection.

Abstract Cowpea [Vigna unguiculata (L.) Walp.] is a legume crop of vital importance to the livelihoods of millions of people in West and Central Africa. It provides a nutritious grain and a less expensive source of protein for both rural poor and urban consumers (Inaizumi et al., 1999). Despite the the importance of the crop, cowpea productivity is generally low at less than 500 kg/ha due to severe attacks from parasitic weeds especially Striga gesnerioides. Historically conventional breeding has been the primary strategy used to develop a number of Striga-resistant varieties currently grown in the Sahel of Western Africa. In this study, we have successfully developed and applied a marker assisted selection (MAS) strategy that employs a single backcross program to introgress Striga resistance into farmer preferred varieties of cowpea for the Nigeria savannas. In this strategy, we have introduced the Striga resistance gene from the donor parent IT97K-499-35 into an elite farmer preferred cowpea cultivar Borno Brown. The selected BC1F2 populations confirmed the recombinants with desirable progenies having Striga resistance gene(s). The lines selected in the BC1F2:4 generations with large seed size, brown seed coat colour and carrying marker alleles were evaluated in the field for resistance to Striga resistance. This led to the selection of a number of desirable improved lines that were immune to Striga having local genetic background with higher yield than those of their parents and standard varieties.