Additive and dominance gene effects in rice (Oryza sativa L.) hybrids through Line x Tester analysis

Abstract

Twenty one hybrids generated from crossing seven lines and three testers were studied along with their parents for combining ability and gene action involved in the expression of characters in rice. The GCA and SCA variance were significant for all the characters. The magnitude of SCA variance was higher than the GCA variance for all the characters revealed the presence of predominance of non-additive gene action for all the characters studied. Among the parents MTU 1010, ADT 39, TRY 2 and IR 50 identified as good general combiner for grain yield as well as other desirable traits like days to 50 per cent flowering, plant height, number of tillers per plant, number of productive tillers per plant, panicle length, number of grains per panicle, kernel length, kernel breadth, kernel L/B ratio, hundred grain weight and grain yield per plant. While the cross combinations viz., MTU1010 x IR 50 and ADT 39 x TRY 2 with good per se performance and significant sca effect for yield and yield components may be exploited by involving them multiple cross breeding programme for obtaining transgressive segregants and broad genetic base population in rice yield improvement.