Combining ability for yield and yield associated traits in rice (oryza sativa l.)

Abstract

Abstract : Twenty hybrids developed using five CMS lines and four restorers along with their parents were evaluated for ten quantitative traits to explain the nature of gene action present in the inheritance these traits. Analysis of variance revealed significant difference among the genotype, crosses and parents. Variance of sea was higher than that of gca for all the characters suggesting the significant role of non-additive gene action on the inheritance of these character. The relative contribution of lines, testers and combination of line x tester for all characters were calculated. It was found that lines were more important and their contribution was high for most of the traits indicated highly influence ... by maternal effects. The cross IR58025A/ BR9157-12-2-37-13-71-32R was the best specific combiner for grain yield. Estimates of gca effects showed that BRRII3A and BR9157-12-2-37-13- 15-40R were the best general combiners for improving yield and other characters. The cross BRRI33A/ BR9159-8-5-49-1-1R was found to be a good specific combiner for most of the characters. It was identified as the most promising hybrid. The cross combination of good general combiner would not always produce the best specific crosses. Moreover, the predominance of production of the best specific crosses from high x low and low x low combiners reported the influence of non-additive and over-dominance gene action on the plant stature.