Population genetic structure and diversity of Teucrium polium in Iran using ISSR markers

Teucrium polium is a Mediterranean native subshrub with large distribution range and high medicinal values which overexploitation of its population has become a serious danger and conservation attempts is needed. Having the genetic information of its population can help to clarify the complicated phylogenetic relationships of species within the sections, genetic conservation and establishing breeding programs to develop cultivars and ultimately preventing declining the populations of T. polium. The genetic diversity parameters and populations structures of 16 populations of T. polium at the local scale in the Alborz mountain range of Iran were assessed using intersimple sequence repeats (ISSR) primers. The averages of polymorphism (P%), Nei’s genetic diversity (H), and Shannon’s Information Index (I) were 33.24%, 0.118 and 0.179, respectively. The population of Asara to GachSar presented the highest P%; 43.28%, H; 0.163 and I; 0.243. AMOVA analysis indicated that, a large portion of genetic variation as within population (77%), and a relatively high genetic differentiation (Gst: 0.311) and gene flow (Nm: 1.107) among populations were observed. UPGMA tree and PCoA plot of ISSR data divided the populations into three genetic groups to a significant extent based on the geographical origins. Similarly, the results showed that, STRUCTURE analysis grouped the populations into three clusters with significant geographical affinity. Teucrium polium exhibited a strong structure and genetic differentiation with low to moderate genetic diversity.