Genotypic diversity of cowpea from lower eastern Kenya

Cowpea is an important pulse crop widely grown in marginal areas of Kenya. There is limited information on diversity among the Kenyan cowpea as it is widely grown from landraces. The aim of this study was to evaluate variation among cowpea landraces obtained mainly from lower eastern region and other marginal areas of Kenya. One hundred and ten cowpea accessions were planted in a Randomized Complete Block Design with three replications. Quantitative and qualitative data were collected and analyzed. Even distribution of accessions across traits of the characters was observed for immature pod color, leaf color, seed shape and testa texture, whereas uneven distribution was observed for terminal leaflet shape, raceme position, pod attachment, pod curvature, mature pod color, flower color and eye color. ANOVA revealed significant differences (p=0.05) of accessions for number of days to 50% emergence, pod length, number of pods per plant and the number of seeds per pod. The first five principal components; 19.8, 18, 15.9, 12.4 and 11.22 respectively accounted for 77% of total variation. Correlation analysis revealed significant relationship (p=0.05) for 50% emergence to 50% flowering, number of pods per plant, terminal leaflet length and terminal leaflet width. The accessions were grouped into two, with one cluster having 103 accessions that included all registered varieties. Therefore, cowpeas grown in marginal lower eastern region of Kenya are variable and closely related to the registered cowpea varieties. The set of accessions could therefore be used for identification of preferred lines for this region.