Genetic Variability Studies in Early Segregating Generation of Cowpea [Vigna unguiculata (L.) Walp subsp unguiculata]

Abstract

Aims: In a self-pollinated crop like cowpea, most breeding approaches predominantly use different techniques of handling the segregating generations. It is important to select and increase the frequency of the desirable genotypes for efficient management of segregating generations and gradual improvement of important characters in the material. For the selection to be efficient, a complete knowledge of the features of the segregating material in terms of genetic variability with regard to important characters is crucial. So the objective of the study was to comprehend the genetic variability in segregating generations and to estimate the percentage of transgressive segregants. Study Design:  The experiment was laid out in Augmented design II during kharif, 2023. Place and Duration of Study: The current experiment was undergone at the Botany garden, Department of Genetics and Plant Breeding, University of Agricultural Sciences, Dharwad, Karnataka to evaluate 36 F4 families and six checks during kharif 2023. Methodology: Observations were taken for ten yield and yield related 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, number of pods per cluster, days to fifty per cent flowering and days to maturity. Analysis of variance (ANOVA) for yield and yield related traits of 36 F4 families of diverse crosses and pedigree along with checks in grain type cowpea was carried out in augmented design II as proposed by Federer and Raghavarao, 1975. Different genetic parameters were estimated to characterize the material for nature and amount of genetic variability. Percentage of transressive segregants was calculated using the mean±1 SD for all characters. Results: The variances between genotypes were shown to be highly significant among all the characters under study. All traits exhibited high heritability (>60%) except the trait number of pods per cluster. High heritability coupled with high genetic advance (>20%) was obtained in traits like total yield (kg/ha) (71.00% and 43.59%), single plant yield (g) (76.18% and 35.01%), number of pods per plant (71.98% and 33.49%), pod length (cm) (75.99% and 22.00%) and number of clusters per plant (64.90% and 30.02%), indicating the possibility of effective selection for these characters. Highest percentage of transgressive segregants was revealed for the traits total yield (19.44%) and days to fifty per cent flowering (19.44%). Conclusion: Sufficient amount of genetic variability present among the F4 families ensures profound scope of selection which in turn indicates possibility of improvement in the population.