Study of Combining Ability in Association with Heterosis in Rice (Oryza sativa L.)

Abstract

In the current investigation, eight lines KNM 12444, KNM 12469, KNM 12472, KNM 13449, KNM 13555, KNM 13568, KNM 14913 and KNM 14985 were crossed with four testers namely Aganni, IBT MRR 24, INRC 3021 and WGL 1119 in Line by Tester mating design during rabi season of 2021-22. The resultant 32 F1’stogether with parents and two commercial checks, KNM 118 and KNM 1638 were evaluated for their combining ability and heterosis at Agricultural Research Station, Kunaram during kharif season, 2022.The analysis of variance for combining ability specified that significant differences were observed due to lines, testers, F1’ hybrids and various interactions indicating the existence of wider adaptability in the material examined. The ratio of gca to sca variances showed that non-additive gene action was predominant in the inheritance of panicle length, plant height, number of productive tillers/plants, grain yield per plant, kernel length, kernel L/B ratio and incidence of gall midge, whereas, preponderance of additive gene action was noticed for 1000 grain weight, days to 50% flowering, number of filled grains per panicle, kernel breadth, hulling percentage, milling percentage and head rice recovery. The gca effects of the parents revealed that, the line KNM 13555 and the testers Aganni, IBT MRR 24 were found to be the best general combiners for single plant yield and its components. Based on the significant sca effects, per se performance, standard heterosis and gall midge incidence, KNM 12469/Aganni followed by KNM 13555/INRC 3021, KNM 13568/IBT MRR 24, KNM 12472/Aganni and KNM 13449/Aganni were identified as promising for single plant yield, its components, quality traits and gall midge incidence. Hence, these parents and F1 hybrids may be further tested for future crop improvement programme.