Combining ability and heterosis in six rowed barley

The magnitude of heterosis and combining ability in six rowed barley was carried out using 5x5 diallel system for plant height, number of spikes per plant, 1000-grain weight and grain yield per plant. Positive heterosis was observed for all the traits except 1000-grain weight Over dominance was observed only for grain yield per plant The heterosis and over dominance for grain yield per plant were positive in all the crosses except K 560 x K 635 where itshowed partial dominance. For 1000-grain weight negative heterosis was observed in all the crosses except BH 495 x PL 508 for plant height positive heterosis was observed in eight cases and over dominance for three. GCA and SCA variances were significant for all the traits except number of spikes per plant at SCA level. The GCA variances were higher than SCA variances in respect of all the traits except grain yield per plant where both GCA and SCA were of same in order. The additive gene effects were generally predominant whereas dominance and over dominance gene effec. were equally important for grain yield per plant