Utilizing heterosis and Combining ability for yield and associated traits in two line hybrid rice system
The inheritance of some rice agronomic characteristics associated with environmental genic male sterile (EGMS), twenty hybrids which produced by crossing among four lines and five testers. Analysis of variance of combining ability revealed significant differences among genotypes, crosses, lines, testers and line x tester interactions. The significant differences among the lines, testers and lines x testers indicated that the genotypes had wide genetic diversity among themselves for all traits except days to heading, chlorophyll content, panicle length and apparent heterosis for parents. Five hybrids WTSC9059S x Sakha101, WTSC9039S x Sakha102, WTSC9059S x Sakha108, WTSC9039S x Sakha108 and WTSC9039S x Sakha101 having better mean yield performance are recommended for heterosis breeding. All traits were studied are governed by non-additive type of genes which necessitates selection in later generations for improvement. Variances of SCA were higher than the GCA variances for traits studied which indicated predominance of non-additive gene action in the inheritance of the traits.