Abstract

Populations with high genetic variability are targeted by breeders as they create opportunity for selection and genetic improvement. To achieve this, multiple populations are created, but resources are often scarce. This calls for identification of populations with the desired traits at early generation. The study was carried out at MUARIK in seasons 2017A and 2017B on 135 F2 and 40 F3 cowpea populations respectively together with 25 parental lines aimed at: Determining best performing populations for yield, resistance to scab, virus and flower thrip based on usefulness criterion and selection index methods. Usefulness criterion computed for yield identified NE 36 x 2392 as the best population. Usefulness criterion computed for yield and its components identified NE 5 x Sanzi as the best population. WC 48A x 2392 was identified as the best population using selection index values that included resistance to virus, thrips, scab, yield and its component and when only yield and its components were fitted in the model. Variability and high yield performance was maintained in the forty best populations identified and therefore amendable for future improvement. No differences were shown among the methods used for selection hence can be adapted for breeding in cowpea.

Key words: Selection index, scab, thrip and virus resistance, usefulness criteria, yield.