Genetic structure of Korean and Japanese population of Hydrangea serrata analyzed by microsatellite analysis

Hydrangea serrata is distributed from the southern part of the Korean peninsula to mainland of Japan. Plants of H. serrata have decorative sterile flowers and fertile flowers in the inflorescence. Colors of decorative sterile flowers vary from white to blue. Many plants have been selected from the wild population and are used in horticulture. This species has been used as an ornamental shrub as well as sources of breeding materials for many hydrangea cultivars. However, the genetic structure of the wild population of H. serrata has not been analyzed yet. In this study 188 individuals from 19 populations of Japan and 14 individuals from Jeju Island of Korea were used for a microsatellite (SSR) analysis of their genetic structures. The analysis revealed that the samples collected from the population in Jeju Island had a closely related genetic structure to that of the samples collected from the populations in the western areas of Japan. The genetic structure of the populations collected in the western areas of Japan were closely related to that of the populations collected in the northwestern areas of Japan. The analysis also revealed that the genetic structure of the population of H. serrata sampled in the western and northwestern areas of Japan was different from that of the populations sampled in the central and eastern areas of Japan.