Genetic analysis of yield and components traits under drought in rice (Oryza sativa L.)

Twenty eight hybrids generated from crossing seven lines with four testers were studied along with their parents and utilized to assess the gene action involved in the expression of characters in rice under drought. The gca and sca effects were significant for all the characters. The magnitude of σ ²_D was higher than the σ ²_A for all the traits studied, showing predominance of non-additive gene action. Among the parents, Danteshwari and Barani Deep of lines IR-36 and Pant Dhan-12 of testers were found to be best general combiners for grain yield and drought tolerant traits. The best cross combinations for sca effects are IR36×Birsa Dhan-105, HUR-105×Birsa Dhan-105, Pant Dhan-12×Danteshwari, Pant Dhan-12×Shushka Samrat and NDR-359×Vandana. Promising hybrids based on per se performance, gca and sca effects are IR36×Birsa Dhan-105, IR36×N-22, HUR-105×Birsa Dhan-105, HUR-105×NDR-97, Pant Dhan-12×Danteshwari, Pant Dhan-12×N22, Pant Dhan-12×Shushka Samrat, NDR-359×Barani Deep and NDR-359×Vandana.