Genetic Association Studies for Indirect Selection for Important Yield and Yield Attributing Traits in Grain Cowpea (Vigna unguiculata L. Walp subsp unguiculata)

Abstract

Aims: The present study encompasses genetic association studies among F4 and F5 families generated from various crosses in grain cowpea (Vigna unguiculata L. Walp subsp unguiculata). Study Design: Augmented design-II for F4 families and checks during kharif 2023 and Randomized block design with two replications for selected F5 families and checks during rabi-summer 2023-24. Place and Duration of Study: The current experiment was conducted at the Botany garden, Department of Genetics and Plant Breeding, University of Agricultural Sciences, Dharwad, Karnataka for the evaluation of 36 F4 families and six checks during kharif 2023 and 27 selected F5 families and five checks during rabi-summer 2023-24. Methodology: The material under experiment included 36 F4 families and six checks evaluated in augmented design-II during kharif 2023. Then during rabi-summer 2023-24, 27 selected F5 families and five checks evaluated in randomized block design. Observations were recorded for nine yield and yield attributing traits viz., total yield (kg/ha), single plant yield (g), number of pods per plant, test weight (g), number of seeds per pod, pod length (cm), number of clusters per plant, days to fifty per cent flowering and days to maturity. Correlation and path coefficients were estimated using standard procedures. Results: Correlation studies indicated that yield estimates were highly positively correlated to all yield attributing traits except to days to fifty per cent flowering and days to maturity. Characters like number of pods per plant (0.59, 0.64), pod length (0.65, 0.58) and test weight (0.39, 0.58) had highest correlations with yield in F4 and F5 generation respectively. Path coefficients further highlighted the character; number of pods per plant (0.363, 0.594) to have the highest direct effect on yield at both phenotypic and genotypic level respectively.