Combining ability analysis for yield and yield component traits in rice (Oryza sativa L.)

One hundred and fifteen hybrids were developed utilizing in Line (5 CMS lines) x Tester (23 testers) fashion and hybrids along with parents were evaluated for eight characters during kharif, 2007 at RARS, Jagtial to understand the gene action in rice. The combining ability analysis revealed significant differences among the parents for all the characters studied indicating the predominance of dominance gene action in governing yield and related traits. This suggests the possibility of exploiting heterosis. Two CMS lines (APMS 6A and CRMS 32A) and six testers (1096, 612-1, GQ-70, GQ-120, KMR 3 and SG 27–77) were found to be good general combiners for yield and other yield attributes. The hybrids APMS 6A x 612-1, PUSA 5A x KMR-3, CRMS 32A x IR 43 exhibited higher specific combining ability with at least one of the parent possessing positive alleles for grain yield. The interrelationship of sca with sca revealed that predominance of non additive gene action viz., additive x dominance and dominance x dominance type for gene interaction for most of the hybrid combinations which could be exploited for heterosis breeding programme in rice.