Hierarchical clustering and path analysid in cowpea [Vigna unguiculata (L.) Walp.]

Abstract

Genetic variability, character association and path coefficient are pre-requisite for selection of trait specific superior genotypes in improvement of any crop and multivariate analysis helps in choosing the parents for hybridization. Studies on 43 diverse genotypes of cowpea indicated the existence of fairly high degree of variability for plant height, number of branches, peduncles and pods per plant, pod weight and pod yield per plant. Higher estimates of heritability coupled with the higher genetic advance for plant height, number of peduncles per plant, number of pods per plant and pod yield per plant indicated that heritability of these traits is mainly due to additive effects and selection may be effective. Correlation analysis pointed out the importance of number of branches, peduncles and pods per plant, pod length, pod weight and number of seeds per pod towards pod yield. Number of pods per plant exerted the maximum positive direct effect on pod yield followed by pod weight and number of branches and peduncles per plant. Selection pressure on these traits may lead to an overall increase in pod yield per plant. Forty three genotypes were mainly divided into 2 clusters with 38 and 5 genotypes at first node. The inter-cluster representatives of distant cluster would be more useful for choosing the partents in cowpea breeding programme.