Heterosis and combining ability analysis for yield and its components in rice (Oryza sativa L.)

Study of heterosis and combining ability were conducted on 40 F1 hybrids along with of 2 CMS lines (females), 20 diverse rice varieties/genotypes as testers (males) to know the pattern of inheritance of some morphological traits for selecting superior genotypes. The experiment was carried out according to line x tester mating design. Analysis of variance revealed significant differences among genotypes, crosses, lines, testers and line x tester interactions for all the ten traits, viz., days to 50% flowering, flag leaf area, plant height, panicle bearing tillers plant-1, panicle length, spikelets panicle-1, grain yield plant-1, test weight, biological yield plant-1 and harvest index. The highest heterosis (197.81%) was observed in cross IR 688897A X Sarjoo 52 followed by other eight crosses for yield and most of its related traits. 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.