Heterosis and combining ability analysis for yield and its components in Indian mustard (Brassica juncea L. Czern & Coss)

Half diallel analysis of eight parents was carried out to identify the high heterotic crosses and their relationship in terms of general and specific combining ability (GCA &; SCA) in Brassica juncea L. Czern and Coss at IARI, New Delhi, during 2007–2008 and 2008–2009. The relative heterosis and heterobeltiosis were observed to be the highest with respect to seed yield per 100 siliquae and days from sowing to 50% flowering in case of cross IC-199715 × IC-199714, EC-289602 × Prakash in the number of primary branches per plant and harvest index, Agra Local × Pusa Bahar in the length of main axis, Poorbijaya × Agra Local in the number of siliquae on main axis and EC-289602 × Pusa Bahar in the biologic yield per plant and seed yield per plant. Different cross combinations exhibited the maximum value of better and mid-parent heterosis for the remaining traits, viz., days to maturity, number of secondary branches per plant, plant height and 1000-seed weight. GCA and SCA variances were significant in all characters. The variance of GCA (σ²g) was observed to be higher from sowing to 50% flowering and maturity in plant height and 1000-seed weight, whereas the variance of SCA (σ²s) was higher in seed yield and other remaining parameters.