Rubus is a member of the Rosaceae family. This plant has more than 750 plant species in the world, which are divided into two groups including blackberries and red raerry. This plant has a wide range of ploidy levels (from 2X to 14X) and the basic chromosome number of Rubus is seven. This fruit has unique properties and is rich in antioxidants, vitamins A, B and C. The roots and leaves have medicinal properties. In addition, the boiled leaves are consumable. There are seven species of Rubus in Iran that all belong to blackberries. Caspian raerry ( R. hyrcanus ) is a species of blackberry which is scattered around the Caspian Sea and there are populations of this species in Iran. Information about variation within a species provides new approaches about evolutionary and conservation genetic strategies of this species. Morphological and ISSR molecular markers were used to study the genetic relationships of 25 populations sampled from three populations that geographically well distributed around the Caspian Sea. The morphological traits were measured and recorded based on the specified codes. In addition, R. discolor was also included as control sample to ensure the validity of collection. In this study, 20 primers were used in which 10 of them had high polymorphism. 10 primers produced 204 bands, 157 of which were polymorphic. Cluster analysis revealed two main groups. The first group includes samples from the North West (NW) and North East (NE), while group 2 included the Central (C) one. R.discolor separated from all R. hyrcanus in dendrogram. The cluster analysis was also performed based on morphological traits. Morphological and Principle Coordinate Analysis (PCoA) confirmed the molecular cluster analysis in most cases. The samples collected from central regions mostly located in sandy soils near the coastal areas of Caspian Sea, while the NE and NW populations were collected from forests in the mountain with high organic matter in the soil. NW and NE populations had relatively similar altitudes, while the Central one was located in lower altitude. Among studied samples, C population showed higher diversity (0.283 0.208),in comparison with others. Finally, narrow genetic base and low diversity was obtained for R. hyrcanus . According to results of this study; the probable origin of this species is central regions of Caspian Sea; during the period of time the seeds of berries were scattered in NE and NW regions. The Alborz Mountains prevented seed dispersal and development of this species into other regions of the country. It is only as a hypothesis, and further studies can lead to more insightful results. Keywords : Fennel blackberry , Rubus hyrcanus, ISSR, Genetic variation, morphology.
