Breeding and Genetics of Drought-Tolerant in Cowpea [Vigna unguiculata L. Walp.]

Abstract The impact of drought on cowpea production in sub-Saharan Africa cannot be overemphasized. However, the use of drought-tolerant cowpea would help mitigate the effect of drought on cowpea production. Hence, the study aimed to breed drought-tolerant cowpea cultivars and determine the genetics of drought tolerance in cowpea. IT98K-205-8 and NG/SA/01/09/004 previously identified as drought tolerant and susceptible were reciprocally crossed in this study. Seeds of both F1 and F2 (selfed hybrids) progenies developed were screened for drought tolerance under simulated 35 days of water stress. Data was taken for drought stress and recovery response when water was re-introduced after drought simulation. A total of 49 hybrid progenies weregotten from the reciprocal crosses of the parents selected and screened in both F1 and F2 generations. Eleven droughts tolerant (85-100% recovery from drought) and nineteen moderate droughts tolerant (50-79% recovery from drought) were developed. A segregation ratio of 9:7 for drought tolerant to drought susceptible signifying duplicate recessive genes was observed in the F2 population and inheritance of drought tolerant trait was independent on the mother plants. Hence, this information will be of vital use in the development of breeding strategies for drought-tolerant improvement in cowpea. Keywords: Drought, recovery, tolerant, water stress, wilting