Genetic Variability and Divergence Studies in Seed, Kernel Traits of Azadirachta indica A. Juss

Abstract

In Azadirachta indica, variability in azadirachtin content and the lack of reliable selection criteria for superior genotypes limit its efficient utilization and improvement. In the present study, 100 neem genotypes were collected from different regions of Telangana, Tamilnadu, Karnataka, Andhra Pradesh and Maharashtra to assess their genetic variability for seed and kernel traits. Seed traits viz., seed length, seed breadth, hundred seed weight, germination percentage and, kernel traits viz., kernel length, kernel breadth, hundred kernel weight was assessed. The data was analyzed using R-open studio to assess the variability. Significant variation was observed among all the genotypes for all the seed and kernel characters studied. Seed attributes viz., hundred seed weight, seed length, hundred kernel weight and germination percentage contribute either independently or in conjunction with one another in enhancing azadirachtin content.Azadirachtin percentage, hundred seed weight and kernel breadth exhibited higher genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV) and genetic advance as percent of mean, whereas all seed and kernel traits showed high heritability, indicating that selection based on these traits would be effective for identifying and exploiting genotypes with high azadirachtin content. The 100 genotypes were grouped into three clusters, with seed length contributing maximum to total genetic divergence. The findings support conservation of diverse germplasm and selection based on performance rather than location. Future research focussing on integrating molecular tools and also explore links between morphological and biochemical traits for effective breeding could be recommend.