Combining ability studies for yield, associated traits and quality attributes in rice for South Gujarat (Oryza sativa L.).

Line x tester analysis using a set of four females, ten males and their forty hybrids was carried out to estimate the general combining ability of parents and specific combining ability of hybrids for yield and ten other associated components in rice (Oryza sativa L.) in a Randomized Block Design during Kharif 2011. GCA variances for females (s2f) were significant at 0.1% level of significance for plant height (40.8), no. of grains per panicle (505.9), grain yield per plant (29.1), test weight(17.9), straw yield per plant (61.3) and kernel L/B ratio (0.2) whereas specific combining ability (SCA) variances for f x m interactions were highly significant for all the characters. Non-additive gene action was prevalent in all characters (Range: 0.03 in amylose content to 0.88 in kernel length breadth ratio) except plant height (1.33) as evident by low GCA to SCA ratio. None of the parents were good general combiner for all traits, however, female IR-28 and male AMT-119 and PNR-546 were good general combiners for a maximum number of traits i.e. five traits out of eleven.. The general combining ability for grain yield per plant for female parent Gurjari (6.19) and NVSR-178 (5.29); and male parents AMT 119 (2.73) and PNR 546 (2.44) makes them a good choice for improving yields in a hybridization programme as these female and male parents are also having significant GCA effects for maximum number of yield associated traits i.e. four and five traits out of eleven for female and male parents respectively. A vis-à-vis comparison of top three specific combining ability crosses with their mean performance showed correlation and these crosses were having at least one good general combining ability parent. [ABSTRACT FROM AUTHOR]