Assessing Genetic Variability, Trait Associations, and Path Analysis in Cowpea for Yield Improvement

Abstract

Cowpea (Vigna unguiculata (L.) Walp.), an important arid legume, is valued for its nutritional value and adaptability to various environments. For a crop improvement programme sufficient presence of genetic variability is of immense importance.  The present study was carried out to assess genetic variation among 65 cowpea genotypes yield and their related traits during kharif 2023 at UAS, Dharwad, Karnataka, India. The experiment was laid out in an Augmented Block Design II. Observations were recorded on five randomly selected plants, averaged and analysed using R software. Variability parameters were calculated, and the seed protein content was determined through the colourimetric method. The results of the analysis of variance indicated significant differences among genotypes for all the traits studied. High phenotypic and genotypic variability was observed for plant height, clusters per plant, pods per plant, seeds per pod, test weight and grain yield, indicating significant genetic potential for crop improvement. High heritability and genetic advance over the mean were witnessed by the traits such as clusters per plant, pods per plant, pod length, seeds per pod, test weight, grain yield, indicating the presence of additive gene action, and it would be more rewarding to bring genetic improvement in cowpea. Seed yield per plant showed significant positive correlation with the number of pods per plant, number of clusters per plant, number of seeds per pod, pod length, and test weight at phenotypic levels. The maximum direct effects on yield were recorded by the number of pods per plant, number of clusters per plant, pod length and number of pods per cluster well as appreciable indirect influences were exerted by the number of seeds per pod and test weight. Thus, these characters could be considered as selection parameters for yield improvement in cowpea as they exerted a positive direct effect on dry seed yield per plant. These findings provide valuable guidance for future cowpea breeding programs aimed at maximising yield under diverse agro-climatic conditions.