Variability, Correlation, Path Coefficient and Genetic Diversity Analysis in Indian Mustard

Phenotypic and genotypic coefficient of variation (PCV & GCV), heritability, genetic advance (GA), correlation, path and diversity analysis for fourteen characters in twenty-five genotypes of Indian mustard (Brassica juncea L.) were evaluated for seed yield and thirteen other yield contributing traits. Genetic variability indicated that, the PCV was greater than GCV for all the traits studied was majorly due to the influence of environment. High heritability along with high genetic advance as percent of mean were recorded for plant height, number of primary branches per plant, number of secondary branches per plant, length of main raceme, number of siliqua on main raceme, number of siliqua per plant, 1000 seed weight, biological yield per plant, seed yield per plant and harvest index, Indicating the breeding improvement through direct selection. In correlation analysis, seed yield per plant had significant and positive correlation with number of primary branches per plant, number of secondary branches, number of siliqua on main raceme, number of siliqua per plant, length of siliqua, number of seeds per siliqua, 1000 seed weight, biological yield per plant and harvest index at both genotypic and phenotypic levels. Path coefficient analysis indicated that, the highest positive direct effects was noted for days to 50% flowering, plant height, number of siliqua per plant, number of seeds per siliqua, length of main raceme, number of primary branches per plant, 1000 seed weight, biological yield per plant, harvest index. Therefore, these traits should be given more priority for selection in breeding programme. Genetic divergence assessed using D2 statistics for characters enabled grouping of all the genotypes in six clusters. Diversity among the clusters varied from 9.67 to 24.03 inter-cluster distances, cluster II and V showed maximum inter cluster distance followed by that between cluster V and VI. The genotypes falling in these clusters could be utilized for hybridization programme in Indian mustard.