Combining ability and heterosis studies for grain yield and its components in hybrid rice (Oryza sativa L.)

Abstract

The study was conducted to know the nature of gene action and level of heterosis in rice hybrids. Analysis of variance revealed the prevalence of non-additive gene action for the traits studied except for days to 50% flowering. The CMS lines IR-79156A and IR-58025A and testers WGL-3962, RNR-15038 and RNR-2781 were best combiners for most important yield contributing traits, like number of productive tillers per plant, number of filled grains per panicle and grain yield per plant by exhibiting positive gca effects. The hybrids, IR-58025A x RNR-15038, IR-79156A x NWGR-3132, IR-58025A x RNR-2781, IR-79156A x RNR-2781 and APMS-6A x RNR-15038 were considered as potential cross combinations for grain yield and its attributes based on per se performance, sca effects, gca effects of parents and standard heterosis. These hybrids could be further evaluated in multi locational trials for commercial use.

Keywords

• hybrid rice
• combining ability
• heterosis
• grain yield