بررسی اثرات تنش آبی بر برخی خصوصیات فنولوژیکی، فیزیولوژیکی و مورفولوژیکی ژنوتیپ های جو (Hordeum vulgare L.) بهاره دیم

­­Drought is one of the most destructive abiotic stresses worldwide that affects growth, development and final yield of crops. Reactions of thirteen rainfed spring 2-row barley genotypes and cultivars of cold areas of Iran to water stress were evaluated based on phenological, physiological and morphological traits. The experiment was carried out as factorial experiment based on a randomized complete blocks design with three replications under three irrigation treatments (normal irrigation and irrigation based on the 60% and 80% of available soil water depletion). The water stress was exerted two weeks before flowering. Results of mean comparisons showed that all the studied traits were reduced with increasing the level of water stress except branching of roots, root length and root length to plant height ratio. Taking all traits together, it is possible to identify two drought tolerant 71938 and 72566-1 genotypes and two Abidar and Dayton/Ranney cultivars which produced the highest yield under normal irrigation and both water stress conditions. Also, 71704 genotype could tolerate the first water stress level but not the second stress level. However, Denmark cultivar didn’t produce favorable yield in normal condition but was comparatively tolerant to both water stress levels. So, after doing competition tests under water stress in actual rainfed conditions in cold-dry and semi-dry land, these genotypes can be recommended for cultivation in these areas, and also can be used for improvement of drought tolerant genotypes in breeding programs.