Gene Action and Combining Ability Analysis Using CMS Based Hybrid Breeding System in Rice (Oryza sativa L.)

Combining ability analysis in rice for hybrid rice breeding programme has been carried out in using L x T mating design with three CMS lines and six testers. The general combining ability of parents and specific combining ability of crosses were estimated for grain yield and its attributes. The ANOVA for combining ability of most traits showed that variances due to treatments, parents, hybrids were highly significant. The SCA variance recorded greater than the GCA variance for grain yield and yield components, suggesting the preponderance of dominance and epistatic gene action in expression of these traits. Among the CMS lines, CRMS31A was identified as a good general combiner for grain yield per plant and most attributing traits followed by CRMS32A. Among the testers R-1162-1667-1-1 was found to be good combiner for grain yield/plant followed by PUSABAS-6(P-1460) and INGER 1–114. Five cross combinations viz., IR79156A/Improved HMT, CRMS31A/BPT4358, CRMS32A/INGER-1114, CRMS 31A/R-1162-1667-1-1 and CRMS32A/Pusa Bas-6 (P-1460) were found to be outstanding with respect to grain yield per plant.