Heterosis and Combining Ability Studies in Indian Mustard under Sodic Soil Condition

The combining ability analysis from a six parent diallel cross of mustard [Brassica juncea (L) Czern & Coss] showed highly significant gca and sea effects for seed yield and other related characters. This signified the importance of both additive and non additive gene effects in controlling the inheritance of traits studies. The estimates of the components of genetic variance obtained from the expected mean value of sum of squares indicated the predominant role of non additive gene action along with over dominance for days to flowering, days to maturity, plant height, number of primary and secondary branches per plant, number of siliquae on main raceme, number of seeds per sillqua and seed yield per plant. Additive gene action along with partial dominance was observed in oil content and 1000-seed weight. The genotype RK-119 was the best general combiner for maximum number of traits among the parents viz; number of primary branches per plant, number of secondary branches per plant and seed yield per plant. Slmllary, the cross combination RK-119 x RK-121 had desirable sea effect in other characters such as plant height, number of secondary branches per plant, number of seeds per sillqua and days to maturity. The extent of heterosis was studied in a diallel cross excluding reciprocals Involving the above six parents and their 15 F_1S for some metric traits under sodlc soil condition to derive Information on the extent of heterosis over economic parent. The common crosses on the basis of the heterotic response as well as sea effects in relation to gca effects were Varuna x Maya, Maya x RK-121, Varuna x RK-120, Maya x RK-120 and RK-119 X RK-121. The crosses exhibited preponderance of additive gene effects.