Genetic variation and genetic advance in cowpea based on yield and yield-related traits

ABSTRACT

The objective of this study was to determine phenotypic variation for yield and yield-related traits among cowpea genotypes and select best candidate genotypes for breeding. Hundred cowpea genotypes were evaluated across two environments using an alpha lattice design with two replications. The pooled data were subjected to analysis of variance, correlation and principal component analyses (PCA). Significant differences were observed among cowpea genotypes for assessed traits. PCA revealed three principal components contributing to 77.75% of the total variation. Grain yield was significantly correlated with most of the traits. The genotypic coefficient of variation was relatively higher, whereas the phenotypic coefficient of variation values were moderate for branch number, seed number per pod, and high for seed number per plant and pod weight per plant. Heritability and genetic advance values respectively ranged from 37.27% to 97.2% and 73.3% to 2242.6% for the studied traits. High direct path coefficient value of 0.71 for pod weight per plant with highly significant correlation with grain yield was observed. The study identified cowpea genotypes such as Glenda RV 465, RV 574, RV 115, RV 28, RV 419, RV 28, RV 419, RV 213, RV 550, RV 470, RV 111, RV 315 and RV 550 with better responses for yield and yield-related traits.