Genetics of yield components for drought tolerant wheat (Triticum aestivum L.) genotypes.

Drought tolerance is a polygenic trait, with a complicated phenotype, often confused by plant phenology. Breeding for water stress is more complex since many types of abiotic stress, such as drought, heat and salt. High yielding wheat genotypes viz., Miraj-06, 9452, 9469, 9272, 9277, CMS-127 and three testers Chakwal-50, Kohistan-97 and Aas-11 were crossed in line × tester mating design. Seed obtained from crosses was evaluated in field conditions for various agronomic traits under drought conditions. Recorded data were subjected to analysis of variance to determine the genetic variability. The data were analyzed statistically and combining ability studies were tested using line × tester analysis to find the relationship between different traits of wheat. High significant differences were observed among the lines and testers for yield related traits under stress conditions. The female line 9452 proved to be best line on the basis of mean performance of traits under water stress. In case of testers, the male parent variety Chakwal-50 retained its performance in maximum number of traits closely followed by Aas-11. The cross combination 9272 × Aas-11 proved best for attaining highest mean for most of traits. In case of GCA effects line 9277 and tester Aas-11 proved best. The cross combinations 9277 × Chakwal50, 9452 × Kohistan-97 exhibited highest SCA effects. The superior genotypes and crosses can be combined to develop new promising and improved varieties under water stress conditions.