STUDIES ON HETEROSIS FOR YIELD AND YIELD CONTRIBUTING TRAITS IN HYBRID RICE

Abstract

Forty hybrids of rice were developed by crossing four CMS lines and ten restorers in line x tester mating design for estimation of heterosis for various yield and yield contributing traits and to identify best hybrid combinations. Heterosis in desirable direction was recorded for important yield and its attributes viz., days to 50% flowering, plant height, panicle length, number of productive tillers per plant, spikelet fertility (%), 1000 grain weight and grain yield per plant (g). The analysis of variance (line x tester) revealed that parents and hybrids differed significantly for all the characters, indicating considerable amount of genetic variability in the material studied. Parents vs hybrids comparison was found significant for all the characters except panicle length. Some of these heterotic crossings have turned out to be the best specific crosses and exhibited desirable per se. Among the heterotic crosses, JMS 13A x RNR 2354 (Grain yield per plant), JMS 13A x JGL 35126 (Duration of fifty percent flowering), CMS 23A x RNR 2354 (Plant height), CMS 59A x RNR 26085 (Panicle length), CMS 13A x RNR 21571 (Number of productive tillers per plant), CMS 59A x ZGY 1 (Spikelet fertility) and CMS 23A x RNR 28411(1000 grain weight) were found to be superior expressing heterosis, heterobeltiosis and standard heterosis in desirable direction. The results of the present study indicated the potential of these parental lines in the improvement of grain yield of rice hybrids.