Genetic Diversity Of Wild Cymbidium Goeringii (Orchidaceae) Populations In Hubei

Wild Cymbidium goeringii (Orchidaceae) plants are becoming extinctive for over- harvesting and habitats fragmentation in Hubei Province recent years. The genetic diversity of 325 individuals from 11 populations in Hubei Province was investigated using inter-simple sequence repeat (ISSR) markers. As a result, 127 bands were amplified by 11 informative and reliable primers, of which 112 (PPL = 88.19%) were polymorphic loci. A relatively high level of genetic diversity were revealed: PPL=88.19%, H_e = 0.2628, H_o= 0.4037 (at species level); PPL = 63.06%, H_e = 0.1945, H_o = 0.2958 (at population level). A higher level of genetic differentiation was detected among populations (G_ST = 0.2440, F_ST = 0.2207) with Nei's G_ST analysis and analysis of molecular variance (AMOVA). Some differentiation may result from habitats fragmentation and barriers to gene flow. UPGMA cluster analysis indicated that five populations from Enshi region grouped together, whereas Dawu population clustered in a clade solely. The Mantel test showed that genetic distance was positively correlated with geographical distance. On the basis of these findings, the following conservation strategies are proposed: (1) In situ conservation will be suitable for Laifeng, Jingshan, and Dawu populations, because them possess sufficient genetic diversity. (2) In contrast, an ex situ strategy should be taken into consideration for Maoba and Xuanen populations, where only a few individuals left.