Genetic Analysis of Some Qualitative and Quantitative Traits in Rice (Oryza sativa L.)

Abstract

The investigation was undertaken to determine the combining ability effects different genetic parameters between some rice genotypes. Line x tester mating design was conducted and 12 F1 hybrid combinations were developed from the cross between 3 lines and 4 testers. There was significant difference between parents, crosses and line x tester interaction for the tested traits. Sakha106 was the best general combiners for heading date, while the line GZ9399 was the best for yield and its components. Among the testers, GZ10101 line was adjudged as good general combiner for 1000-grain weight trait. The crosses Giza178 x Egyptian Yasmin and Sakha106 x GZ10101 were the best hybrid based on specific combining effects for the most important traits. The dominance genetic variance (σD) was greater than the additive genetic variance (σA) in controlling the inheritance of all the studied traits, except flag leaf area was governed by the additive genetic variance. Heritability values are high for plant height and sterility %, indicating slight effects of environment on the traits. On the contrary, the contributions of the lines were higher than the contribution of the testers for no. of panicles/plants, no. of filled grains/panicle, sterility % and grain yield/plant. Cluster analysis divided the seven rice genotypes and their hybrid combinations into two main groups based on morphological traits especially plant height, no. of filled grains/panicle traits and sterility %. Studying of combining abilities is effective in identifying the better parents and helps in the selection of better parent for successful breeding.