Combining Ability and Heteroses Analysis for Seed Yield and Yield Components in Brassica napus L.

Line × tester analysis of three testers and five lines of Brassica napus L. were used to estimate combining ability and heterosis of plant height, number of primary branches, number of secondary branches, 1000-seed weight and seed yield per plant.Significant mean squares of treatments for yield components and seed yield indicated significant genetic variations among the genotypes including parents and their crosses.Parents Vs crosses mean square indicated, average heterosis was significant for all the traits except plant height.Line × tester mean square was significant for all the traits.High GCA to SCA ratio; indicated the prime importance of additive genetic effects for all traits except seed yield per plant.Significant positive general combining ability (GCA) and specific combining ability (SCA) effects were observed.Most of the crosses had significant positive over better parent heterosis of seed yield, indicating that these hybrids were suitable candidates for improving these traits using combination method.