Evaluation of Drought Tolerance in Barley Genotypes (Hordeum vulgare L.) using Drought Tolerance Indices

Extended Abstract Introduction and Objective: Drought stress is one of the most important factors in reducing yield and barley production in rainfed arid regions, and counteracting or reducing the effect of stresses as a useful solution to increase barley yield. Therefore, improvement of stress-tolerant and suitable barley cultivars for arid and semi-arid regions is essential. Material and Methods: In order to evaluate drought tolerance of 121 genotypes, lines and barley cultivars and identify tolerant and susceptible genotypes based on grain yield and drought tolerance indices, an experiment in a randomized complete block design with two replications in Maragheh rainfed agricultural research station was carried out in rainfed and irrigated conditions during the cropping years of 1394-94 and 1394-95. Evaluated traits included spikes number, seeds numder, 1000-seed weight, days to heading, days to maturity and grain yield. Results: The results of correlation between drought tolerance indices and grain yield in rainfed and irrigated conditions showed that tolerance index (STI), mean productivity (MP), harmonic mean (HM) and geometric mean productivity (GMP) were positively correlated, and had significance with grain yield traits in both environmental conditions. So, they were suitable indicators for selecting high yielding cultivars in both rainfed and irrigated environments. Also, the number of fertile spikes and 1000-seed weight had a significant correlation with STI, GMP, MP and HM indices in both conditions. In the principal components analysis based on drought tolerance index and grain yield under water conditions, the three components together accounted for 81% of the diversity of the initial data. In rainfed conditions, the three components described about 88% of the total diversity. Conclusion: In this study, genotypes 10 (71557), 100 (Tokak / Demir-2) and 38 (72480) in both rainfed and irrigated environments showed higher grain production potential than other genotypes.