Evaluation of Several Drought Tolerance Criteria in Cultivated Varieties of Barley (Hordeum vulgare L.) and Their Relationships with Yield Reduction

摘要

Drought is the most significant constraint for crop production in the world. Therefore, employing high-yielding cultivars tolerant to drought is an effective approach to reduce its detrimental effects. Six barley cultivars were evaluated to screening drought tolerant cultivars in two different conditions of irrigation. The experiments were arranged based on randomized complete block design with three replications at the research station of College of Agriculture, Shiraz University, Shiraz, Iran. The cultivars in the first experiment meet normal irrigation condition (100% field capacity; FC) while these cultivars in the second experiment were exposed to water-stressed condition (no irrigation after anthesis). Grain yield, its components and drought tolerance indices based on grain yield of the genotypes such as Tolerance (TOL), Mean Productivity (MP), Susceptibility Index (SI), Stress Susceptibility Index (SSI), Geometric Mean Productivity (GMP) and Stress Tolerance Index (STI) were calculated. Analysis of variance showed highly significant differences among the barley cultivars for yield and its components in normal and stress conditions. Yield in non-stress (Yp) and stress (Ys) conditions showed positive and significant correlations with STI, MP and GMP. PCA analysis also indicated that STI, MP and GMP were more reliable indices to screen drought tolerant barley cultivars. The results revealed that Lokht-Himalia and Dorla were sensitive and semi-sensitive, respectively. Other evaluated barley cultivars were tolerant to drought. Therefore, they may be recommended for cultivate in drought prone regions. Also these cultivars can be used in barley breeding programs aimed at improving drought tolerance.