Evaluation of Bread Wheat Genotypes under Drought Stress Conditions using Drought Tolerance indices and SSR Molecular Markers.

36 bread wheat genotypes including 6 improved and introduced cultivars and 30 other genotypes that are collected and prepared from different regions of Iran and other countries were evaluated in two irrigation conditions (normal and limited irrigation) in two separate randomized complete block design with three replications in both moisture conditions. By measuring the average yield for each genotype in each environment, tolerance and stress susceptibility indices were calculated and the relationship between a number of micro satellite markers (associated with drought tolerance) and drought tolerance of genotypes were studied. The genotypes were divided into three groups( tolerant, semi tolerant and susceptible) by cluster analysis based on Stress Tolerance Index (STI), Geometric Productivity Mean (GMP), Mean Performance (MP) and Yield Index (YI) as well as grain yield under stress conditions .
Genotypes 11.113, 1553, 176, 198, 3798, 689, 894, 9016, 910, 99, Kohdasht, Pishtaz, Zagros, Sivand And Genotypes 1637, Sardari, 2047, 2103, Azar 2, 871, 890 were identified as tolerant and semi tolerant genotypes respectively. Cluster analysis based on micro satellite markers also divided the genotypes into three groups. Comparison of dendrograms revealed a significant relationship between drought tolerance and SSR markers. As well as , regression analysis between the grain yield in both conditions, GMP, STI, MP as dependent and marker bands as independent variables showed that(WMC179 , WMC307 and WMC322) are the most effective marker in( MAS) for improving yield under stressed and non-stress conditions.