Genetic variability and trait association studies in Indian mustard (Brassica juncea)

Thirty released varieties of Indian mustard [Brassica juncea (L.) Czern and Coss.] were evaluated during winter (rabi) 2006-07 and 2007-08 under irrigated and rainfed environments. Analysis of variance on 14 quantitative traits was carried out and pooled analysis over the environments was conducted. The mean, range, phenotypic, genotypic and environmental variance, genotypic and phenotypic coefficient of variation, heritability in broad sense and genetic advance were calculated. Path coefficient analysis was carried out using correlation, coefficients to know the yield- contributing traits having true associations with seed yield. Improvement in seed yield can be achieved by selection using the correlation and path analysis data generated in this study. 1 000-seed weight was positively correlated with siliqua length. 1 000-seed weight and total siliquae/plant also had higher phenotypic and genotypic direct effects on seed yield/plant, revealing that indirect selection for these traits would be effective in improving seed yield. The high heritability coupled with high genetic advance for 1 000-seed weight would also be of great use for indirect selection for improvement in seed yield. The material used in the study is of diverse nature and can be used in the breeding programme for development of improved genotypes in mustard.