Comparison of Bread Wheat Genotypes Tolerant to Late Growth Stage Water Deficit Stress using Stress Tolerance Indices

Water deficit stress in the late growth stage is one of the limitation factor of wheat production in arid and semi-arid regions such as Iran and introduction of stress tolerant varieties is one the strategies that conquer to it. In this research, the reaction of 15 bread wheat genotypes against to water deficit stress at the late growth stage were inspected using stress tolerance indices. Hence, bread wheat genotypes were studied in both normal and stress states separately using randomized complete block design with three replications in farm condition. Analysis of variance revealed significant differences among studied genotypes based on tolerance indices. Mean comparison manifested that genotypes 3 and 8 could consider as suitable genotypes for water deficit stress at the late growth stage. Classification of genotypes based on studied tolerance indices located them into three groups. Among studied indices, GMP, STI, YSI and SSI were identified as suitable indices in selection of tolerant genotypes for water deficit stress at the late growth stage because they possessed significant relation with environmental yields. Results of triangle plots showed that genotypes 3 and 8 have the highest seed yield in both stress and non-stress conditions based on GMP, STI and SSI indices (Group A) and could effectively use in water stress state in the late growth stage.