Comparative diversity analysis of cowpea genotypes using multivariate approaches

Cowpea improvement is possible if the information on genetic diversity among existing genotypes is available. Principal Component Analysis and Mahalanobis D² analysis were used to analyse 30 cowpea genotypes based on eleven quantifable traits. The whole variance was divided into eleven major principal components using PCA, with the top three PCs with eigenvalues >1 accounting for 69.47 per cent of the total variation. From the analysis of the frst two PCs and Mahalanobis D² analysis, it was confrmed that genotypes viz., AVCP-1, PGCP-1, PGCP-13, CGD-1406, and CGD-1439 were scattered apart in all four quadrates of the bi-plot and fall in clusters with high inter-cluster distance representing maximum genetic variation. As a result, 30 cowpea genotypes had genetic and phenotypic differences that could be used to improve the cowpea by simple selection and crossing potential parents.