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

Forty eight cross combinations were obtained by the crossing of sixteen lines with three testers in line × tester design and F₁ along with parents used for assessing the combining ability effects for the quantitative traits. The present study showed that the variances due to line x tester's differ significantly for all the traits which indicating the importance of SCA and non-additive gene action. The estimated values of sca variances were higher than the corresponding values of gca variance for all the traits. The average degree of dominance was more than unity (>1) indicating over-dominance for all the characters. Among the parents lines viz., CSAR 839-3, CSR-13, T-3, IR-79495-9-3-2-3, Sarjoo 52, CSR-36 and NDR 359 found to be good general combiner for grain yield/plant and several important traits to emerge as valuable parents for hybridization programme for obtaining high yielding varieties or transgressive segregants of rice. Among the cross combinations, seventeen combinations had significant and positive SCA effect for grain yield per plant and its attributes and best five crosses were, NDPK-5088×NDR-359, T-3 ×Pusa Basmati, Ramraj × CSR-36, Sarjoo-52 × NDR 359 and Usar-3 × Pusa Basmati could be used for heterosis breeding programme for improvement of quantitative and yield traits.