Study on Genetic Variability in Cowpea [Vigna unguiculata (L.) Walp]

Cowpea [Vigna unguiculata (L.) Walp] also known as a black-eyed pea or Southern pea, belongs to Fabaceae family is rich in proteins, vitamins, minerals and phosphorus. It is mainly grown for grain, pulse cum vegetable and fodder purposes. Twenty-seven genotypes of cowpea were sown in RBD with three replications and observations regarding eighteen characters were recorded at the vegetable farm, RPCAU, Pusa, Samastipur during zaid-2017. Analysis of variance shows that there was a significant difference among genotypes recorded among all the eighteen quantitative characters indicates the diverse genetic nature of base population. The coefficient of phenotypic variation was slightly greater than those of genotypic variation for almost all the character shows that the existing variation is mainly governed by the genotypic factor and there is little influence of environment in the expression of the character. High heritability coupled with high genetic advance was observed for characters like pod yield per plant, plant height, pod yield (q/ha), number of pods per plant and number of nodes on the main stem shown that the direct selection will be more effective. Genetic divergence using D2 analysis was also carried out for all the twenty-seven genotypes and were grouped into six clusters. Cluster I was largest including of eleven genotypes whereas cluster VI was smallest consisting only one genotype. Inter-cluster D2 values ranged from 606.11 to 1837.92. The high value of D2 distance help breeder in selection of the parental line for initiating any hybridization programme.