ارزیابی تحمل به خشکی در ارقام یولاف در شرایط آب و هوایی اصفهان

This study was conducted at the Research Farm of Isfahan University of Technology in 2003 to evaluate drought tolerance potential of 20 oat (Avena sativa L.) genotypes including 14 cultivars released in Canada, two cultivars released in the United States of America and Switzerland and four Turkish breeding lines. A randomized complete block design with three replications was used in each irrigation treatment (i.e., irrigation after 70±3 and 130±3 mm evaporation from class A pan). Results of analysis of variance revealed significant differences among cultivars for all studied traits in both irrigation treatments, with the exception of plant height at heading stage and biological yield in stress condition. Stress condition significantly reduced all the traits. Also, the interaction of genotypes by irrigation treatments was significant for days to heading, grain and biological yields and 1000-grain weight. To evaluate drought tolerance of the studied cultivars, Rosielle and Hamblin tolerance index, mean productivity (MP), Fischer and Maurer stress susceptibility index and Fernandez geometric mean productivity and stress tolerance index were calculated based on yield data in stress and non- stress conditions. According to the obtained results, stress tolerance index seems to be the most effective index to identify tolerant genotypes. Rank correlations of stress tolerance index and grain yields in stress and non-stress conditions were 0.93 and 0.78, respectively. Based on this index, Boyer and Paisley were found to be the most tolerant cultivars.