Abstracto

Heterosis and combining ability for grain yield and its contributing traits in bread wheat (Triticum aestivum L.)

SK Jain and EVD Sastry

Six lines were crossed with four testers in line x tester fashion to determine the general and specific combining ability for yield and yield contributing traits in wheat. The mean square due to gca and sca were significant for most of the traits which indicates the presence of both additive and non additive gene effects for controlling the expression of yield and yield contributing characters. The σ2 gca / σ2 sca ratio suggested that the presence of non additive gene action was predominant for most of the characters including grain yield. Varieties viz., HD-2687 and WH- 542 among lines and K-65 and Raj.-3077 among testers were adjudged the best general combiner as it depicted high gca effect in desirable direction for grain yield and yield contributing traits. Among the selected hybrids WH-542 x Raj-3077 and WH 542 x K-65 were exhibited highest magnitude of positive significant sca effects with highest magnitude of heterobeltiosis and per se performance for grain yield. In general, close association between sca effects and heterobeltiosic was observed among the best hybrids identified on the basis of sca effects for grain yield.