Exploitation of Gene Action and Heterosis for Improvement of Agronomic and Grain Quality Traits in Basmati and Red Rice under Mid-Hill Himalayas

Genetic Dissection of Yield and Grain Quality Traits in Basmati and Red Rice

Abstract

Gene action, combining ability and heterosis estimates were worked out through Line × Tester analysis of 20 hybrids developed by crossing 10 basmati / aromatic lines with two red rice genotypes to determine the genetic architecture of various agronomic and grain quality traits for development of superior hybrids for Himalayan hill conditions. Analysis of variance revealed significant differences among genotypes, F1 crosses, lines and testers for all the traits in the present studies. Preponderance of non-additive gene effect for all the traits, realized by ratio of σ2GCA / σ2SCA, was less than unity and magnitude of dominance variance was higher than additive variance. It was also supported by boxplot and PCA analysis. The association analysis revealed that grain yield improvement was primarily driven by enhanced tillering ability and panicle architectural traits, and also association with head rice recovery traits. It suggested the feasibility of simultaneous improvement of grain yield and quality. The estimates of GCA effects indicated that male parent “HPR 2795” and female parents “RYT 3178”, “HPR 2590”, “HPR 2800-2” and “Pusa Basmati 1121” were good general combiners for agronomic traits. Three heterotic cross combinations, HPR 2590 × HPR 2795, RYT 3178 × HPR 2720, and HPR 2800-2 × HPR 2795 were identified based on per se performance, SCA effects and standard heterosis that can be further utilized for commercial hybrid rice breeding.