Genetic diversity and population structure of Iranian oak (Quercus spp.) accessions based on ISSR and CBDP markers

Quercus brantii var. persica and Quercus infectoria are two economically and ecologically important oak species widespread in the Zagros forest, located in the northwestern and southwestern parts of Iran. An effective study of the genetic diversity and population structure of these genetic resources is still unexplored. In the present study, 48 accessions of the mentioned oak species collected from different regions of Kermanshah province were subjected to a study of genetic diversity and population structure using two sets of markers (inter-simple sequence repeats [ISSR] and CAAT-box derived polymorphism [CBDP]). CBDP markers showed greater efficiency in detecting polymorphism in the oak individuals studied. The analysis of molecular variance [AMOVA] showed that the genetic variation within species, as well as within regions per species, was higher than between species. Quercus brantii var. persica had the highest values for all indicators of genetic variability. Moreover, at the regional level, the Dalahoo populations in both species showed the highest genetic diversity using the ISSR markers. This population, along with Gilan-e-Gharb had the highest genetic diversity using the CBDP markers. The results indicate a high level of genetic diversity in isolated regions, which in turn promotes the formation of population structure. Therefore, this may contribute to further conservation and genetic improvement of Iranian oak germplasm.