Identification of sources for drought tolerance in local bread wheat landraces

In order to identify drought tolerant germplasm, 97 bread wheat landraces, mostly Iranian genotypes, were evaluated in two separate experiments of normal and drought stress conditions in the field of Agriculture and Natural Resources Research Center of Varamin. The experiments were performed in lattice statistical design with three replications. Drought conditions in the stress experiment was exerted by irrigation stoppage at the spike emerging stage. Agronomic traits were measured and drought tolerance indices were calculated. The results of combined ANOVA indicated significant differences among genotypes and between conditions as well as genotype  × conditions interaction for all the evaluated traits. STI, GMP, HM and MP were known as the best indices for the selection of drought tolerant genotypes. Thirty genotypes, located in A region of Fernandez grouping method, had a higher grain yield in both stress and normal conditions. Four principal components explained 71.44% of the total variation. The first component differentiated drought tolerant genotypes with early spike emerging and the second one emphasized on later spike emergence, larger harvest index and shorter plant height. The results of this research identified a large number of superior drought tolerant genotypes which could be exploited in wheat drought breeding programs.