AFLP Analysis of Genetic Diversity of the Endangered Species Sinopodophyllum hexandrum in the Tibetan Region of Sichuan Province,China

Amplified fragment length polymorphism (AFLP) markers were used to estimate the genetic diversity of seven wild populations of Sinopodophyllum hexandrum (Royle) Ying from the Tibetan region of Sichuan Province, China. Six primer combinations generated a total of 428 discernible DNA fragments, of which 111 were polymorphic. The percentage of polymorphic bands (PPB) was 25.93 at the species level, and PPB within population ranged from 4.91 to 12.38%. Genetic diversity (H _E) within populations varied from 0.01 to 0.04, averaging 0.05 at the species level. As revealed by the results of AMOVA analysis, 58.8% of the genetic differentiation occurred between populations, and 41.2% within populations. The genetic differentiation was, perhaps, due to the limited gene flow (N _m=0.43) of the species. The correlation coefficient (r) between genetic and geographical distance using Mantel's test for all populations was 0.698 (P=0.014). The UPGMA cluster analysis revealed a similar result in that the genetic distances among the populations show, to a certain extent, a spatial pattern corresponding to their geographic locations. On the basis of the genetic and ecological information, we propose some appropriate strategies for conserving the endangered S. hexandrum in this region.