Genetic diversity and gene-pool subdivisions of diploid D-genome Aegilops tauschii Coss. (Poaceae) in Iran as revealed by AFLP

The diploid goatgrass Aegilops tauschii is considered the D-genome donor of bread wheat and has probably a centre of diversity in north of Iran. In order to measure the genetic diversity of and the relationships among different populations, varieties and subspecies belonging to Ae. tauschii in Iran, DNA was extracted from 48 accessions of Ae. tauschii collected across the geographic range of the species in the Country and the genetic diversity was assessed using AFLPs based on eight PstI/MseI +3 primer pairs resulted in 277 bands, 198 of which were polymorphic. High level polymorphism was detected, with an average of polymorphism rate of 0.715; relatively low genetic similarity (0.455) between accessions and significant difference between the lowest (0.179) and the highest genetic similarity (0.817). The Iranian Ae. tauschii populations showed high level of genetic diversity. The populations studied were divided into two groups: one group was mainly representing Northern populations collected from Southern Caspian Sea shore and the other group was mainly representing Northeast and Northwest populations. Based on the results of this study, it can be suggested that Ae. tauschii possesses two separate gene-pools in Iran: Northern and Northeastern-Northwestern. Considering the needs for introducing new characteristics and alleles for wheat improvement purposes, Ae. tauschii Iranian gene-pool is assumed to be of high importance for more investigation in the future.