Genetic diversity in populations of the endangered medicinal plant Tetrastigma hemsleyanum revealed by ISSR and SRAP markers: implications for conservation

Genetic diversity of 27 Tetrastigma hemsleyanum accessions from wild or cultivated populations was evaluated using SRAP (sequence-related amplified polymorphism) and ISSR (inter-simple sequence repeat) markers. ISSR and SRAP analysis yielded 112 and 66 scorable amplified bands, respectively, of which 85.71 and 77.27 % were polymorphic. ISSR revealed efficiency over SRAP due to high Shannon's Information Index (I), Nei's gene diversity (H), and total genetic diversity (Ht). The dendrograms showed clear clustering pattern of geographically distribution. The correlation between the coefficient matrices for the SRAP and ISSR data was high (r = 0.869, P < 0.01). Higher level of genetic similarity was observed in intra-population than in inter-population. The average genetic similarity among cultivated populations were far above that among wild populations, the low level of gene flow, distance isolation, and asexual reproduction were likely related to the low level of differentiation among populations. The promotion of genes exchange will be very beneficial to conserve and utilize the enormous genetic variability contained in the T. hemsleyanum.