Genetic Diversity and Clustering Pattern in Groundnut (Arachis hypogaea L.) for Yield Traits Using D² Analysis

Abstract

Arachis hypogaea L. is a critical oilseed crop in India. It occupies the premier position in terms of cultivated area and is second only to soybeans in production. Despite exhibiting considerable morphological, biochemical, and physiological variability, the cultivated groundnut has a narrow genetic base. This limitation is attributed to its monophyletic origin, a lack of gene flow from wild relatives due to ploidy barriers, and its self-pollinating nature. The study aimed to understand the genetic diversity and clustering pattern in groundnut (Arachis hypogaea L.) for yield traits using D² analysis. A study was conducted on 21 groundnut genotypes (5 parents and 16 crosses) during the kharif season of 2023-24 at RVSKVV, Gwalior, to assess genetic variability, heritability, genetic advance, and divergence for 12 yield and yield-attributing traits. The data were subjected to different statistical analyses, viz., analysis of variance (ANOVA), magnitude of genetic variability was performed following the standard procedures, phenotypic and genotypic coefficient of variation. Analysis of variance revealed significant differences among genotypes for all traits, indicating substantial genetic variability. High genotypic and phenotypic coefficient of variations were observed for key yield components like number of pods per plant, pod yield, kernel yield, and biological yield per plant. High heritability coupled with high genetic advance as a percentage of mean was recorded for these traits, suggesting the predominance of additive gene action and the potential for effective phenotypic selection. Mahalanobis D² analysis grouped the 21 genotypes into five distinct clusters. The maximum inter-cluster distance was observed between Cluster III and Cluster V, identifying them as the most divergent genotypes for crossing to achieve high heterosis and genetic recombination. The character biological yield per plant contributed the most (46.67%) to total genetic diversity. The results demonstrate the existence of significant genetic variability and highlight specific traits and genetically divergent parents that can be effectively utilised in future groundnut breeding programs for yield enhancement.