D2 Analysis in Indian Mustard (Brassica Juncea)

Abstract

The present investigation entitled, "D2 analysis in Indian mustard (Brassica juncea)" involving thirty five genotypes was undertaken to examine the genetic variability, heritability, genetic advance, correlation coefficient, path coefficient analysis and genetic divergence. All the thirty five Indian mustard genotypes were tested in randomized block design with 3 replications during rabi 2011-12. Observations were recorded for days to 50% flowering, days to maturity, plant height (em), number of primary branches per plant, number of secondary branches per plant, number of siliquae on main Shoot, number of siliquae per plant, number of seeds per siliqua, length of main shoot (em), 1000-seed weight (g), biological yield per plant (g), seed yield per Plant (g), harvest index (%) and oil content (%). Analysis of variance revealed substantial amount of variability among the genotypes for all the characters, under study, indicated wide spectrum of variability among the genotypes. High heritability coupled with high genetic advance were observed for number of primary branches per plant, number of secondary branches per plant, number of siliquae on main shoot, number of siliquae per plant, length of main shoot, biological yield per plant, seed yield per plant, harvest index and 1 000 seed weight. Improvement in yield can be made by selecting these yield contributed traits having high heritability coupled with high genetic advance. Phenotypic correlations were of higher magnitude as compare to their corresponding genotypic correlation in most of the character combination. Seed yield was found to be positive and significantly correlated with harvest index, 1 000-seed weight, number of seed per siliqua, number of siliquae per plant, number of secondary branches per plant. Thus any selection based on these characters will enhance performance and improvement in Indian mustard. Path coefficient analysis showed that harvest index, number of siliquae per plant, biological yield per plant, 1 000-seed weight and number of seed per siliqua were the most important characters, controlling directly to seed yield. Mahalanobis D2 statistic revealed considerable genetic diversity among the genotypes. The genotypes grouped into six clusters. The IV and V cluster having the maximum number of genotypes. This envisaged that the genotypes grouped within a particular cluster are more or less genetically similar to each other and apparent wide diversity is mainly due to the remaining genotype distributed over rest of the other cluster. Divergence study suggested that crosses involving genotypes like Varuna, Vaibhav, EC-365404, EC-401467 with Arvali and EC- 365442 for getting desired segregants from breeding point of view.