Genetic and Environmental Variation of Seed Yield, Yield Components, and Seed Protein Quantity and Quality of Cowpea1

Abstract

Pure line cultivars of cowpea (Vigna unguiculata (L.) Walp.) were grown in the field at Ile‐Ife, Nigeria, and the biotron and greenhouse at Madison, Wis., in both short‐ and long‐day environments to study yield, yield components, percent protein, and amino acid content of the mature seeds. Seeds/pod, 50‐seed wt, and methionine content demonstrated medium to high broad sense heritability and the other traits were medium to low. Genotypic variance components for 50‐seed wt, seeds/pod, percent protein, mg of methionine/g of flour and g of methionine/l00g of protein, and genotype ✕ location components for 50‐seed wt and percent protein were statistically significant and large enough to be of practical importance. Genotypic and phenotypic correlations of yield with 50‐seed wt were high and positive, whereas those for yield with percent protein, yield with methionine content, and 50‐seed wt with tryptophan content were negative and relatively high. ‘Producer,’ which is high in percent protein and yield, is a promising parent in crosses with Nigerian local cultivars