Morphological evaluation and drought tolerance indices of Aegilops cylindrica accessions in Ilam

In order to introduce drought tolerance indices on 48 accessions of Aegilops cylindrica an experimental augmented design based on a randomized complete block design with 4 replications was conducted under non-stress and drought stress conditions at Agricultural Research Station of Ilam University. Combined analysis showed variation among the genotypes and also showed different responses of genotypes in stress and non-stress conditions. Based on the results of simple correlation analysis between the indices and biological yields of populations, Arithmetic Mean Productivity, Geometric Mean Productivity, Harmonic Mean Productivity and Tolerance Index  showed strong correlation with biological yield in both stress and non-stress conditions and were efficient in screening populations. Principal components analysis showed that the first and second components were able to explain 91.49% of the variation. The first component, explaining 61.26 % of variation, confirmed the efficiency of mentioned indices for screening tolerant populations. Accordingly, with respect to the distribution of populations in biplot made by the first and second components, populations 9, 24, 34, 43, 42, 35, 45, 47, 48, 23, 18, 3, 26 and 4 had the highest performance in both normal and drought stress conditions and based on Arithmetic Mean Productivity, Geometric Mean Productivity, Harmonic Mean Productivity and Tolerance indices had a good tolerance to drought stress. Populations 14, 36, 10, 32, 17, 20, 12, 15, 46, 40, 11 and 37 had good performance in normal conditions. Populations 25, 41, 33, 5, 6, 2, 7, 44, 1 and 8 had optimum performance in drought stress. Populations 13, 16, 19, 21, 22, 27, 28, 29, 30, 31, 38 and 39 had week performance in both normal and drought stress conditions. Cluster analysis was relatively confirmed by principle components analysis. Populations 34, 24, 43 and 9 were introduced as tolerant populations with high biological yield in both normal and drought stress conditions at Ilam province climates.