Evaluation of Genetic Variability of Durum Wheat Genotypes Based on Physiological Characteristics in Drought Conditions Using the GGE-BIPLOT Method

In order to study the genetic variability based on the physiologic and drought tolerance indices of 20 genotypes of durum wheat, an experiment was carried out in research farm and physiology laboratory of Agricultural and Natural Resources Campus of Razi University of Kermanshah, Iran, in a randomized complete block design with three replications under stress and non-stress conditions in 2013-2014. The results of analysis of variance for different agronomic, physiological and biochemical traits showed that the effect of genotype on the characteristics of water stored in cut leaves, water use efficiency, stomata conductance, chlorophyll b, total chlorophyll, grain yield, activity of catalase enzymes, peroxidase and superoxide dismutase were significant. Comparison of mean of different traits showed that genotypes 20, 5, 3, 1, 12 and 13 had the highest values. The correlation analysis in drought stress revealed that the grain yield with chlorophyll b and total chlorophyll as well as relative water content had a significant positive correlation with photochemical efficiency of photosystem II. Significant negative correlation was observed between the water stored trait of cut leaves and the level of activity of the enzyme superoxide dismutase. There was a significant positive correlation between chlorophyll a content with chlorophyll b and chlorophyll content as well as between chlorophyll b and total chlorophyll. The GGE-BIPLOT showed that the genotypes 5, 6, 20, 9, 2, 3, 10, 4, and 19 were identified as superior genotypes for studied traits. Such comprehensive information on genotypes is important for converting them to cultivars and introducing them to farmers, as well as choosing parents for hybridization.