Variability studies and multivariate analysis in Indian mustard [Brassica juncea (L.) Czern & Coss] 

Abstract

A study on genetic variability and genetic divergence was done with 50 genotypes for 13 quantitative characters in Indian mustard (Brassica juncea (L.) Czern and Coss). The analysis of variance indicated the prevalence of sufficient genetic variation among the genotypes for all the 13 traits. The wider phenotypic range, high heritability coupled with high genotypic coefficient of variation (GCV) and high genetic advance as per cent of mean (GA %) were observed for seed yield per plant, biological yield per plant, number of secondary branches per plant, number of siliquae per plant and 1000-seed weight which, indicated that response to selection would be very high for these yield components ultimately leading to seed yield improvement in mustard crop. The genotypes grouped in 9 clusters when grouped using the Tocher's method. Cluster I topped with maximum (33) genotypes followed by cluster II (6) and cluster III and IV (each of 3). While, cluster VII to IX were solitary clusters. Maximum genetic distance (D) was found between cluster II and VI followed by between cluster III and IV. Four clusters viz., II, III, IV and VI were important with respect to construct plant ideotype including seed yield per plant, which could be utilized for breeding programme. Three traits viz., days to 50% flowering, days to maturity and 1000-seed weight also contributed more than 55% towards total genetic divergence.