Assessment of diversity in Quercus brantii populations of the north Zagros forests using morphological and molecular ISSR and IRAP markers

In this study, the intra- and inter-population genetic diversities of 125 genotypes representing nine populations of Quercus brantii from North-Zagros forests were studied using leaf morphological characteristics, inter simple sequence repeats (ISSR) andinter retrotransposal amplified polymorphism (IRAP) markers. Cluster analysis based on morphological characteristics differentiated significantly the nine Q. brantii populations into six main groups.  Eighteen ISSR and 10 IRAP primers amplified a total of 233 and 129 fragments of which 224 and 126 fragments were polymorphic, respectively. Both ISSR and IRAP marker systems revealed high genetic diversity at species level (ISSR: h= 0.24, PPL = 98.71%; IRAP: h= 0.21, PPL = 99.22%). Estimated coefficient of genetic differentiation (Φ_ST) based on ISSR and IRAP primers were 0.23 and 0.16, respectively indicating most of the total genetic variation distributed within populations than between populations for both marker systems that confirmed with molecular analysis of variance (AMOVA). The low level of genetic diversity between populations and high genetic differentiation among individuals within populations were probably due to extensive gene flow resulted from wind pollination of oaks. Cluster analysis for both molecular marker systems grouped these nine populations into distinct clusters within UPGMA dendrograms. There was no significant correlation between genetic distances of populations and geographic distribution distances with mantel test.