بررسی تنوع ژنتیکی ارقام گندم نان و قابلیت برخی شاخص‌های مقاومت به تنش در انتخاب ارقام مقاوم به خشکی آخر فصل

Drought stress seriously influences productivity and quality of wheat. This study was carried out to evaluate the ability of stress indices for screening late-season drought stress tolerant and sensitive wheat cultivars. Eighteen bread wheat cultivars were grown in a split plot arrangement based on complete block design with three replications during 2010-11 and 2011-12 growing seasons at experimental farm of faculty of agriculture, Shiraz University. Main plots were assigned to irrigation regimes and sub-plots to wheat cultivars. The results showed that stress tolerance index (STI), mean productivity (MP) and geometric mean productivity (GMP) were highly positively correlated to grain yield in both irrigation regimes, so, they appeared to be useful indices for screening late-season drought stress tolerant cultivars. Based on the results of cluster and principle component analyses, wheat cultivars were clustered to three main groups in which cultivars placed in the third group including Darya and Tabasi based on biplot diagram, were drought tolerant and high yielding cultivars in both irrigation regimes. Thus, using these cultivars as parental lines in breeding programs could be useful for producing high yielding cultivars for late season stress conditions.