Genetic Variability in Natural Iranian Populations of 'Cupressus sempervirens' var. Horizontalis in Caspian Sea Coastward Assessed by SSR Markers

The cypress (Cupressus sempervirens var. horizontalis) is one of the east Mediterranean plant elements. This species was evaluated as one of four native conifers in Iran that has high genetic and ecologic value. It was chosen to study due to its initiate importance as one of Iranian genetic resources. This research was carried out by using SSR molecular markers to determine the genetic variation of this species in order to evaluate genetic diversity of cypress species in three sites which are protected as reservoir sites in north of Iran. Results showed that the total diversity was 0.276 in SSR molecular system. All the 8 SSR loci were polymorphic, having a total of 125 alleles among the 60 diploid individuals. The overall mean of expected and observed heterozygosity of populations was 54.18% and 62.93%, respectively. The highest and lowest PIC values were recorded for Cyp101, Cyp139 (0.33) and Cyp257 (0.19) primers. It is found that the average Genetic distance value within Mazandaran and Golestan are higher than that within Gilan. Dendrogram was constructed using UPGMA method and divided all accessions into 8 major groups. Populations were easily discriminated by the first three PCO axes, which explaining 81.41% of total variance. In conclusion, by using SSR marker systems, intra-population diversity was achieved more than inter-population diversity.