Evaluation of Spring wheat Cultivars for Physiological, Morphological and Agronomic Traits under Drought Stress

For evaluation of the reaction twenty of spring wheat cultivars under complete irrigation (control) and drought stress condition starting before booting stage, an experiment was conducted in split plot basis of Randomized Complete Block Design with 4 replications in two cropping years (2010-2011 and 2011-2012) in research farm of Agriculture Faculty, University of Tabriz. The results of variance analysis of traits were showed significant difference between stress levels and between cultivars for all studied traits. Stress cause to significantly decrease of grain yield, yield components, plant height and other morphological traits. Also, values of physiological traits have decreased under drought stress and this decrease was not similar for all cultivars. Further, quantitative amounts of root traits were increased for plant defense apposite to drought stress and this increase was more in tolerant cultivars than others. On the other hand, assessment of correlation coefficients between traits was showed that grain yield had the highest positive and significant correlation with number of spike per plant under control and drought stress conditions. Also, dendrogram of cluster analysis grouped cultivars into four groups under both of control and drought stress conditions. According to achieved results of mean comparisons and cluster analysis, Kavir, Niknejhad, Darya, Moghan3 and Marvdasht were the most tolerant cultivars and Bahar was the most sensitive cultivar. So, it seems that these tolerant cultivars are suitable for direct culture in farm that has limitation for irrigation during end of growth period.