Studies on component of genetic variance and heterotic response in rice (Oryza sativa L.) for high yield with quality and sodicity tolerance

Abstract

A study was conducted to evaluate the potential and limitations of using component of variance and combining ability for establishing heterotic patterns in rice (Oryza sativa L.) under the sodic soil. The results revealed highly significant variations within parents and hybrids (F1s) indicating a wide genetic variability for 18 quantitative and qualitative characteristics and the possibility of genetic improvement of rice. Estimates of specific combining ability (SCA) variance were higher than the corresponding estimates of general combining ability (GCA) variance for majority of the traits. Parents such as NDRK 5062, NDRK 5037, Sarjoo 52, Narendra 2064, NDRK 5081, NDRK 5004, NDRK 5039, CSR 10, NDRK 5059 and FL 478 showed significant and positive GCA effects for grain yield per plant, and some of the yield-contributing traits to emerge as useful donor for hybridization programmes. Twenty three crosses emerged with positive and significant SCA effects for grain yield per plant from 63 F1s. A wide range of variation in the estimates of heterobeltiosis and standard heterosis in positive and negative direction was observed for grain yield per plant and other related traits. Top five F1s that showed good heterotic potential for grain yield and yield contributing traits over Jaya (SV1) as well as CSR 43 (SV2) were NDRK 5037 x Narendra Usar Dhan 3, NDRK 5062 x IR 28, NDRK 5062 x CSR 23, NDRK 5037 x CSR 23 and NDRK 5040 x Narendra Usar Dhan 3. The findings will help promote rice improvements in context to establishment of heterotic patterns as a requirement for a sustainable long-term success of hybrid rice breeding