Terrestrial orchids with flshy tubers have long been exploited as a source of bioactive compound for the curing of a diverse range of health problems, as well as in dietary supplements and as an aphrodisiac in different parts of the Iran and on a world basis. Harvesting of orchid tubers from Iranian species for salep has been escalated in recent years by national and international demand and the Iran has become one of the main suppliers for this trade. In this study we aimed to evaluate genetic diversity of some tuberous terrestrial orchid species from western part of Iran by means of molecular markers. Understanding the differences among the biogeographic, demographic and the human-mediated impacts on the level and distribution of genetic diversity is crucial for conservation management of terrestrial orchids species. For this purposes, 7 population (totally 42 samples) of Anacamptis coriophora, Orchis mascula, Dactylorhiza umbrosa and Dactylothiza unvelliana species collected from different geographical locations of western regions (Kurdisan, Kermanshah and west Azarbaijan provinces) of Iran as well as from Chaboksar (Gilan province) were analyzed using four start codon targeted (SCoT) markers. A mean number of 39.14 SCoT bands were scored for 7 studied populations. Number of different allels, number of effective allels and Shannon’s information index were 6 ± 0.031, 0.24 ± 0.01 and 0.045 ± 0.0, respectively. Cluster analysis based on Jaccard’s distance (cophenetic correlation, r= 0.842) classifid 42 orchid samples under 7 group. In this regard all studied orchid species well-classifid based on species and geographical locations. Orchis mascula and Anacamptis (Orchis) coriophora individuals were fallen close together showing their close phylogenetic relationships. On the other hand, all Dactylothiza umbrosa as well as Dactylothiza unvelliana were grouped together. Geographical populations were also well classifid based on obtained dendrogram using UPGMA metho
