Assessment of Genetic Variability and Diversity in Inbred Lines of Maize (Zea Mays L.)

Abstract

An experiment was conducted during Rabi, 2025-26 at the Agricultural College Farm, Naira, Srikakulam District, to estimate genetic variability and diversity among 30 maize inbred lines. The material was evaluated in a randomised complete block design with three replications, and observations were recorded for 12 quantitative traits. Analysis of variance showed significant differences among genotypes for all traits, indicating the presence of variability in the experimental material. High genotypic and phenotypic coefficients of variation were recorded for grain yield per plant (26.55% and 26.97%), anthesis-silking interval (21.42% and 23.46%), 100-kernel weight (20.36% and 20.92%) and number of kernels per row (20.17% and 21.05%). Ear height also showed high estimates, with GCV and PCV values of 22.97% and 22.43%, respectively, as recorded in the study. High heritability coupled with high genetic advance as a percentage of the mean was observed for anthesis-silking interval, plant height, ear height, ear length, number of kernel rows per ear, number of kernels per row, 100-kernel weight and grain yield per plant, suggesting the importance of additive gene action for these traits. Based on Mahalanobis' D2 statistics, the 30 inbred lines were grouped into six clusters. Cluster I contained the highest number of genotypes (12), followed by cluster III (7) and cluster II (6), while cluster VI was monogenotypic. The highest inter-cluster distance was recorded between clusters III and IV (559.19), whereas cluster V showed the highest intra-cluster distance (197.20). These results indicate that genotypes from clusters III and IV may be considered for hybridisation to exploit divergence and improve yield-related traits.