Decoding diversity: Integrative assessment of genetic variability, trait associations and nutritional profiling in cowpea genotypes

Pulses occupy a unique place in India's nutritional food security, as they are a rich source of protein. Cowpea (Vigna unguiculata L.) is an important pulse crop contributing significantly to protein and micronutrient security in India. However, there is a need for more research on the potential and actual yields of cowpea in India. Cowpea, being a self-pollinated crop, exhibits limited variability. The present study aimed to assess genetic variability, divergence, character association and nutritional quality among 65 cowpea genotypes to identify superior yield-contributing traits and promising genotypes. A field experiment was carried out at the College of Agriculture, Navile, Shivamogga, using an augmented design. High genotypic and phenotypic coefficients of variation were recorded for pods per cluster, pods per plant, clusters per plant and seeds per pod, indicating substantial variability. High heritability coupled with high genetic advance as a percentage of mean for these traits suggested the predominance of additive gene action and a good response to selection. K-means clustering grouped the genotypes into five clusters, with the maximum inter-cluster distance observed between Clusters IV and V, indicating wide genetic divergence. Crossing these divergent genotypes is expected to generate higher heterosis and wider variability. Correlation and path coefficient analyses revealed that clusters per plant exerted the strongest positive direct effect on seed yield per plant. Based on mean performance, genotypes VCP-17-019, PMCP-1131, 202854(97) and EC-472271 were identified as superior, exhibiting high yield and enhanced nutritional quality. These genotypes recorded crude protein content ranging from 20.00–27.25 %, along with appreciable levels of calcium, magnesium, iron and zinc. The study highlights key yield-associated traits and nutritionally rich genotypes that can be effectively utilised in cowpea breeding programmes aiming at yield improvement and nutritional enhancement.