To enhance productivity, genetic restructuring of Indian mustard germplasm is needed to develop high-yielding cultivars or hybrids. In the present investigation, 55 genotypes (10 parents, and 45 F1s) of Indian mustard were assessed to study the character association among traits and to know the gene action, which aids the breeder to evaluate the proportional contributions of various components towards genetic diversity. The field experiment was laid out in a RandomizedBlock Design with three replications during rabi 2017-18 and 2018-2019. The correlation study revealed that seed yield per plot showed a positive and significant correlation with days to 50% flowering, plant height, primary branches/plant, secondary branches per plant, secondary branches per plant, and number of siliquae per plant. The path coefficient analysis revealed that seed yield per plot, days to 50% flowering and plant height have a positive direct effect on seed yield per plant, which suggests that direct selection for these traits can be done for improvement of yield. As a consequence of path coefficient analysis, the highest direct positive effects were observed for number of siliquae per plant followed by days to maturity, main shoot length and seeds per siliquae. Both additive and non-additive gene action were important in controlling days to 50% flowering, days to maturity, plant height (cm), primary branches per plant, main shoot length, siliquae on the main shoot, siliquae length (cm), number of siliquae per plant, seeds per siliquae and oil content. Symmetrical proportion of positive and negative genes (H2/4 H1) was observed for all the characters. In the case of heritability, narrow sense showed the highest values in plant height and moderate in days to maturity and remaining characters showed low values of narrow sense heritability. The predominance of non-additive gene action for seed yield per plant and its components could be explored through heterosis breeding.
Kumar et al. (Mon,) studied this question.