Microsatellite genetic variation in the Chinese endemic<i>Eucommia ulmoides</i>(Eucommiaceae): implications for conservation

Abstract

Eucommia ulmoides, a traditional Chinese medicinal plant, is endangered as a consequence of long-term and widespread harvest in the late 20th century. It has been widely cultivated as a source of herbal medicine and for use in the organic chemical industry in China. In this study, eight microsatellite markers were applied to investigate genetic diversity in E. ulmoides. Three hundred individuals from one semi-wild population and nine cultivated populations across its main production area were collected. A high level of genetic diversity at population levels (HE = 0.716) was observed. The highly outcrossed mating system, high longevity of E. ulmoides and seed admixture may be responsible for high genetic variation within populations. A genetic bottleneck was observed in one population. Populations were only slightly differentiated from one another (FST = 0.063); this was also supported by AMOVA, which revealed that 94.05% of the total variation resided within populations. This is probably attributable to long-distance gene flow mediated by the exchange of seeds by local farmers. Implications of these results for the conservation of genetic resources of E. ulmoides are discussed.