Evaluation of Drought Tolerance in Grain Sorghum Genotypes (Sorghum

Evaluation of drought stress tolerance in sorghum genotypes at different growth stages and severity of stress and their reaction is very important in breeding programs. This study was conducted with the 13 grain sorghum genotypes in 3 different environmental conditions including normal condition and two water deficit conditions at vegetative and reproductive stages using randomized complete block design with 3 replications. Genotypes grouping were performed based on tolerance and sensitivity indices by cluster analysis. There was a positive and significant correlation between grain yield with tolerance indices (MP, GMP and STI) and sensitivity indices (SSI and TOL) in both normal and two water deficit conditions. The results showed that STI, GMP and MP indices were the best indices for evaluation of genotypes response in drought stress conditions. Cluster analysis showed that B26 genotype and M2 promising line had the most grain yield and higher values of STI، GMP and MP indices in both normal and stress conditions and they grouped in the same cluster.