Masoud Bakhshayeshi; Morteza Shekarchizadeh
Abstract
Drought stress is one of the most important environmental factors that affect growth, development, and production of plants. To identify drought resistant genotypes and screening the quantitative indices of drought resistance, 23 bread wheat genotypes were tested in a randomized complete block design ...
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Drought stress is one of the most important environmental factors that affect growth, development, and production of plants. To identify drought resistant genotypes and screening the quantitative indices of drought resistance, 23 bread wheat genotypes were tested in a randomized complete block design with three replications. The study was conducted under irrigated and rainfed conditions in the research station of Dryland Agricultural Research Institute (DARI), in Maragheh. Based on the potential (Yp) and stress (Ys) yield, quantitative criteria of drought resistance including mean productivity (MP), tolerance index (TOL), geometric mean productivity (GMP), harmonic mean (HM), stress susceptibility index (SSI), and stress tolerance index (STI) were calculated. The results of mean comparison showed that the highest potential and stress yield were related to the genotypes number 12 and 16, respectively. The highest stress tolerance index (STI), tolerance index (TOL), geometric mean productivity (GMP) and harmonic mean (HM) were related to the genotypes number 16, 17, and 6. The results of correlation analysis between indices, mean potential and stress yield indicated that the most suitable criteria for screening the genotypes under irrigated and rainfed conditions was stress tolerance index (STI). Factor analysis based on principal component analysis method indicated that two important factors accounted for about 99.84% (drought tolerance 73.28% and sensitivity to drought 26.56%) of the total variation among traits in drought and non-drought stress conditions.