AN INVESTIGATION ON THE DISTRIBUTION AND GENETIC DIVERSITY OF Eurycoma longifolia JACK, AND in vitro CONSERVATION OF THIS VALUABLE MEDICINAL TREE IN THUA THIEN HUE, VIETNAM

E. longifolia is a valuable medicinal tree and has a long history of usage in traditional medicine in Asia. However, overexploitation is currently causing the depletion of this species in many places. A preliminary study was carried out to get an idea on the distribution and genetic diversity of E. longifolia in Thua Thien Hue Province, Vietnam, and in vitroculture of this valuable medicinal species for conservation. The results indicate that E. longifolia distributes in two main site types: sandy soil and mountains. In mountains, they can live at an elevation of over 1000 m, though mainly focused at 300-700 m. RAPD markers were used to assess the genetic diversity of E. longifolia collected from 3 natural populations. A total of 13 individuals were analyzed using 10 RAPD primers and produced 73/394 (18.5%) polymorphic DNA fragments. The UPGMA dendrogram formed 4 significant clusters (Phu Loc at an elevation <100 m, Nam Dong >200 m, Phong Dien, and Nam Dong <200 m). Micropropagation through in vitro germination of seeds and direct shoot regeneration from in vitro explants was conducted. About 50% of seeds germinated after 11 days of culture and the highest percentage (70%) was obtained from seeds of yellow fruits. The stem segments from in vitro seedlings had the highest number of regenerated shoots (4.8 shoots/explant) with 1.2 cm in height on the medium MS supplemented with 0.5 mg/L BAP.