Study of Heritability Gene Action and Combining Ability Using CMS Line in Hybrid Rice (Oryza sativa L.)

Low heritability (h²_ns) estimate was observed with grain yield plant^-1 and test weight indicating preponderance of non-additive gene action to govern these traits. Combining ability revealed higher specific combining ability variance than their respective general combining ability variances indicating the predominance of non-additive gene effects indicated relevance of heterosis breeding for improving the yield and yield contributing attributes. Among the testers high gca was recorded in Sarjoo 52 and Narendra Usar 3 for harvest index, grain yield plant^-1, days to 50% flowering (earliness), plant height (dwarf stature), panicle bearing tillers plant^-1 and biological yield. Among the female parental lines, IR 58025 was observed as a good general combiner only for seedling height, panicle length, spikelets panicle^-1, test weight, biological yield palnt^-1. Cross between IR 688897A X Sarjoo 52 , IR 58025 A X 21-2-5-B-1-1, IR 58025 A X Narendra Usar 3 and IR 58025 A X IR 71829-3R-73-1-2-B shown favorable per se performances and higher significant positive sca effects in related to grain yield plant^-1. These combinations proved to be good hybrids based on CMS system in rice.