Genetic variability and divergence in Indian mustard [Brassica juncea (L.) Czern & Coss.]

Abstract

The present investigation was undertaken to study the extent of genetic variability and divergence among twenty diverse genotypes of Indian mustard (Brassica juncea (L.) Czern & Coss.) for yield and its contributing traits. The experiment was conducted during the Rabi season of 2024-25 at the Experimental Farm of G H Raisoni University, Saikheda, Madhya Pradesh, using a randomized block design with three replications. Observations were recorded on ten quantitative traits including seed yield per plant, plant height, number of siliquae per plant, number of primary branches, siliqua length, seeds per siliqua, biological yield, and 1000-seed weight. The analysis of variance revealed significant differences among genotypes for all traits studied, indicating substantial genetic variation. High genotypic and phenotypic coefficients of variation were recorded for seed yield, siliquae per plant, and biological yield. These traits also exhibited high heritability and genetic advance, suggesting a predominance of additive gene action and good scope for improvement through direct selection. Genetic divergence using Mahalanobis D² statistics grouped the genotypes into five distinct clusters using Tocher’s method. The maximum inter-cluster distance was observed between Cluster I and Cluster V, suggesting that crosses between genotypes from these clusters may result in maximum heterosis. Among the genotypes, V1, V3, and V9 performed superiorly and can be recommended as potential parents in breeding programs aimed at genetic improvement of Indian mustard.