Evaluation of Maize Hybrids Tolerance to Drought Stress

Breeding for environmental stress is one of the most important goals in plant breeding. Among stresses, drought stress has high influencing on limitation of maize production. Therefore, in order to find the best drought tolerant hybrids, 38 maize hybrids were planted in two separate experiments: one with optimum irrigation (control) and another with water stress at grain-filling stage in Moghan at two years. RBCD experiment design with three replications was used. Stress Susceptibility Index (SSI), Mean Productivity (MP), Tolerance (TOL), Geometric Mean Productivity (GMP) and Stress Tolerance Index (STI) indices were used to evaluate susceptibility and tolerance of the genotypes. Results showed that, K74/2-2-1-3-1-1-11×K3653/2 and SC704 hybrids had higher grain yield than mean in all irrigation conditions. These hybrids had the highest STI and located at part of high yield potential and low sensitivity to drought in the biplot. On the other hand, paternal line of majority of drought stress tolerant hybrids was the line K3653/2. Therefore, it is recommended to use this line in breeding maize to get to the most tolerant hybrid. Also the results showed that despite ofthe MP,GMPandSTI indices were most successful in selecting high yield tolerant hybrids, however using biplot the most tolerant hybrids to drought can be chosen the best.