Gene action and combining ability analyses to develop NPT based rice hybrids in Chhattisgarh plains

Combining ability in New Plant Type (NPT) lines of rice for hybrid rice breeding programme has been carried out in line x tester mating design involving 3 CMS lines and 6 testers. The analysis of variance for combining ability of all the traits showed that variances due to treatments, parents, hybrids were highly significant. The analysis further revealed highly significant differences for all the characters among the lines, testers and line X tester and parents’ vs hybrids. Among the CMS lines IR 58025A was identified as a good general combiner for grain yield per plant. Among the testers NPT line HR 703 (3.09) was found to be good combiner for grain yield per plant followed by Jirashankar (NPT-Sel) (2.36) and IIRON N-1-114(0.79). The significant difference between lines x tester interaction indicates that SCA attributed heavily in the expression of these traits and demonstrates the importance of dominance or non additive variances for all the traits. Three crosses viz., IR 58025A/HR 703, IR 79156A/IIRON N-1-114, and CRMS 31A/PAU1196 were identified as most promising based on SCA effects, better per se performance and both the parents with high or low GCA effects.