Heterosis and combining ability in rapeseed (Brassica napus L.)

A nine-parent diallel study conducted on the yield components and oil content in rapeseed (Brassica napus L.) revealed that mean squares due to general and specific combining ability were significant, suggesting the importance of both additive and dominance components. Parents GSL, 8809, HPN-1, GSL 1501 and HNS 8803 were good combiners for seed yield and some of its components, and oil content. Estimates of heterosis over better parent (BP) for various traits indicated significant magnitude for seed yield (−14.8 to 82.8%), primary branches (−26.0 to 193.6%) and siliquae per plant (−21.9 to 162.6%). Unidirectional dominance was observed for most of the traits studied. The cross GSB 7027 XHNS 8803 gave highest positive heterosis for seed yield per plant.