Molecular Characterization of Syrian Aegilops L. (Triticeae, Poaceae) Species Using ISSRs

Species of Aegilops L. are important genetic resources due to their close genetic relationship with cultivated wheat species. Syrian Aegilops species are, however, still neglected and therefore endangered of extinction. The value of those species as a genetic resource for wheat cultivar improvement depends on the amount of genetic variability they represent relative to cultivated crops. Therefore, genetic variation and phylogenetic relationships among 14 Syrian Aegilops species were assessed in this study using the PCR-based Inter-Simple Sequence Repeat (ISSR) technique. The phylogenetic tree constructed for species targeted showed that the diploid species Ae. tauschii and Ae. speltoides appeared in a basal position of the tree and differed significantly from other Aegilops species, and were the closest to the reference sample of Triticum aestivum. Remaining species were grouped in two separate clusters. In the first cluster, Ae. searsii and Ae. vavilovi were revealed as sister species. The second cluster included the other ten species which belong to the section Aegilops except for Ae. markgrafii (Cylindropyrum) and Ae. crassa (Vertebrata). The phylogenetic tree also revealed that there was no correlation between the ploidy level of the species analyzed and their clustering which was, generally, in agreement with botanical classifications of the genus.