Increased genetic erosion and consequent reduction in genetic diversity have been the most important breeding obstacles to improving wheat yield in recent years. High genetic diversity is a requirement for response to selection in segregating generations and is the main factor in genetic improvement. The wild ancestors of bread wheat in Iran, characterized by their high genetic diversity, represent one of the world’s rare and valuable gene resources. It is widely recommended that utilizing these genetic pools can significantly contribute to the advancement of wheat breeding programs. This study aimed to evaluate the genetic diversity of 10 ecotypes of Aegilops tauschii by evaluating 33 different traits, in a randomized complete block design with 3 replications, during two consecutive planting periods under normal moisture conditions. The effect of ecotype was significant for all the traits. In general, it can be stated that the present germplasm has sufficient diversity for the selection of different traits, especially grain yield and yield components, and accordingly, selection in this germplasm may result in response to appropriate selection. Ecotype A19 had the highest and ecotypes A15, A16 and A17 had the lowest grain yield per plant, respectively. It is likely that ecotype A19 allocates a substantial portion of it´s assimilates to aerial tissues and organs, particularly to grain yield and its components. Traits such as peduncle length, plant height, water use efficiency, harvest index, and spikelet number per spike showed a positive and significant correlation with that of grain yield and also demonstrated a high broad-sense heritability. Furthermore, days to spikelet and days to pollination traits with high heritability showed a significant negative correlation with yield. The results of correlation analysis showed that most root traits and phenological traits, except for the length of grain filling period, had a negative genotypic correlation with grain yield, suggesting that plants allocated a major part of their photosynthetic materials to reproductive parts, including yield components, during a limited period of the growing season had higher grain yield. In the biplot diagram, since a small amount of both the first and second components were desired, the area 3 of the bi-plot, was introduced as the most desirable biplot region. Accordingly, the genotypes and traits that were in the area 3 of the bi-plot, were introduced as the most desirable genotypes and traits. Based on the results of cluster analysis, the ecotypes were placed in two separate groups. The ecotypes in the first cluster had the highest amount of root and phenological traits and the lowest grain yield. While, the ecotypes of the second cluster showed the lowest amount of root and phenological traits and the highest grain yield. Based on the results of the discriminant function, the grouping of ecotypes into two groups was confirmed completely. The results indicated the existence of high genetic diversity in the evaluated germplasm, which could be used in future wheat breeding programs.
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