Development of Some Cowpea [Vignaunguiculata (L.) Walp.] Accessions for Tolerance to Drought Stress

The study was conducted in Nigeria at the screen house of International Institute of Tropical Agriculture (IITA), Kano Station, during 2012 and 2014 growing seasonsto develop Cowpea genotypesthat are tolerant to drought stress with a view to solving the problem of climate change faced by the Cowpea farmers in Sub-saharan Africa where annual rainfall is not stable, based on the outcome of this study it was observed that Breeding programme carried out with IT07K-322-40 which is ahighly susceptible variety was used in both forward and reciprocal crosses and all the crosses involving it proved to be drought tolerant. This indicates that the gene for drought tolerance is highly heritable, response of F₁ progenies to drought stress revealed that, out of the ten (10) successful F₁ progenies evaluated (Table1).five (5) were found to be drought tolerant, also four (4) were found to be drought susceptibleand the remaining one which is IT03K-378-4 x IT07K-322-40 was found to be intermediate.Backcross progeniesindicate that out of the ten (10) successful backcross progenies tested for drought stress (percentage wilting and recovery), a total of seven (7) cowpea genotypes were found to be drought tolerant and two (2) others were rated drought susceptible (IT07K-322-40 x IT03K-378-4) x IT03K-378-4 and (IT07K-322-40 x IT07K-297-13) x IT07K-297-13,the remaining one was rated as intermediate (IT07K-291-92 x IT07K-297-13) x IT07K-297-13.The result of the backcross progenies indicatedthat out of the total, ten (10) successful backcross progenies tested for drought stress, a total of seven (7) cowpea genotypes were found to be drought tolerant,two (2) others (IT07K-322-40 x IT03K-378-4) x IT03K-378-4 and (IT07K-322-40 x IT07K-297-13) x IT07K-297-13 were rated drought susceptible andthe remaining one (IT07K-291-92 x IT07K-297-13) x IT07K-297-13 was rated as intermediatewhich indicates that among all the methods of breeding carried out, the result of tolerance supersede other methods