Study of line x tester analysis, combining ability and per se performance in rice (Oryza sativa L.)

Abstract

The analysis of variance for combining ability revealed significant differences due to lines and testers for all the characters indicating wide genetic diversity among lines and testers. The lines x testers’ interaction components also emerged significant for all the twelve traits which indicated that combining ability contributed more in the expression of these traits. Among the CMS lines, IR 58025A having ‘WA’ type of cytoplasm was found to be good general combiner for grain yield and its major components. The line, NDMS 4A was poor general combiner for grain yield and most of the components but showed better ability to combine for plant height and panicle length. Among restorer lines, CR 792-B4-2-1R was found good general combiner for grain yield and biological yield. Other good combiner was TTB 517-17-SBIR-70149-35R noticed for total number of spikelets panicle-1, number of fertile spikelets panicle-1 and number of sterile spikelets panicle-1. The higher magnitude of sca than gca variances and greater value of average degree of dominance and lower predictability ratio were observed for all the twelve characters except days to maturity, suggesting significant role of non-additive gene action for these traits which results from dominance /epistasis and various other interaction effects that are non-fixable.