Sustainable management of genetic resources requires knowledge about the phylogenetic and phylogeographic status of species, as well as the genetic structure of populations. Persian oak (Quercus brantii) is one of the most important species in the Zagros forests of western Iran. The quality and quantity of these forests have been reduced due to human destruction and drought-induced climate change. The first aim of this study was to examine the phylogeny and phylogeography of the Persian oak in western Iran. Stratified random sampling was used to collect occurrence points and genetic materials. In each location, 2-5 individuals were collected with a 1000-meter distance between them. In total, 72 samples were collected from 21 locations. DNA was extracted from samples, and the ITS gene was PCR amplified. Samples with high quality were sent for sequencing. The phylogeny of the Quercus genus was conducted using samples of Iranian oak, other oak species in Iran, and West Asian oak species. Maximum likelihood and Bayesian approaches were employed, and the time of divergence of different oak species was estimated using the molecular clock, calibrated with available fossils. The haplotype network was examined using minimum spanning, median joining, and TCS algorithms. The second objective was to eva‎luate the diversity among and within Iranian oak populations with different habitat conditions in the Zagros forests and to determine the geographic pattern of this species. Genetic difference indices, such as nucleotide diversity, haplotype diversity, Fst, and molecular variance analysis, were calculated within and between Persian oak subclades. Bayesian grouping was used to examine the genetic structure in Persian oak. In the third objective, the ecological niche of this species and its subclades, along with the two species Q. infectoria and Q. libani, were modeled in this area using ensemble modeling in biomod2, R software. The climatic niche overlap of these three species and three subclades of Persian oak was assessed using the PCA-env approach. The results of the phylogenetic analysis showed that the samples of Persian oak were divided into three subclades. The molecular clock showed that the most recent common ancestor of Persian oak existed about 19 million years ago in the Miocene era, corresponding to the Zagros Orogeny. Based on the analysis of molecular variance (AMOVA), the percentage of changes within populations (78.13%) is higher than among them (19.98%). The Bayesian grouping determined three clusters in Persian oak populations, confirming the genetic structure of Persian oak populations. The fixation index (Fst) was 0.22, which was statistically significant. The haplotype and nucleotide diversity were 0.98 and 0.01 in the species, respectively. The nucleotide diversity of subclades was 0.01, 0.01, and 0.008. The ecological niche modeling showed that Random Forests, Maxent, and Maxnet algorithms were the most accurate and corresponded to reality. For this reason, these algorithms were used to produce the ensemble map of ecological niches. Based on the results, annual precipitation was identified as the most important factor influencing the niche suitability of the three oak species and three subclades of Persian oak in the Zagros region. The similarity and equivalency tests confirmed that the niche overlap among these species is significantly high. In addition, these two tests confirm a high niche overlap among three subclades of the Persian oak. These results confirm the niche conservatism among the three mentioned oak species and three subclades of the Persian oak.

منصوره ملكيان

جمال الدين خواجه الدين , مصطفي تركش اصفهاني

محمدرضا اشرف زاده , حسين بشري , سيما فاخران اصفهاني