Abstract Periploca forrestii Schltr. is one of the national medicine in the Yunnan-Guizhou plateau of China.In order to assess the genetic diversity of Periploca forrestii Schltr. from different geographic population at molecular levels, sequence-related amplified polymorphism (SRAP) molecular markers were used to detect the genetic diversity of 11 P.forrestii Schltr. accessions and 4 P.calophylla (Wight) Falc. accessions for the first time mainly from Southwest China (Yunnan, Guizhou, Chongqing and Sichuan). Forty primer pairs had been selected to identify the polymorphism among the 15 test materials and 420 distinguishable DNA fragments were amplified, of which 333 bands were polymorphic. The percentage of polymorphic bands in average was 79.29%. The range of genetic distance of the test accessions was 0.040~1.613 with an average of 0.840, and the genetic similarity coefficient(GS) of them was 0.391~0.973 with an average of 0.718. All of these suggested that the genetic diversity was comparatively rich among the test materials. The 15 accessions were classified into 2 cluster groups of P.forrestii Schltr. and P.calophylla (Wight) Falc. by cluster analysis using UPGMA(unweighted pair-group method with arithmetic mean) at the similarity coefficient of 0.59. At the similarity coefficient of 0.80, the 11 accessions of P.forrestii Schltr. could be furtherly classified into 3 sub-groups which reflected the 3 geographical origins of Yunnan, Guizhou, Chongqing-Sichuan. Moreover, accessions from the same origin frequently clustered into one group, showing a certain degree of eco-geographical distribution. Results of this study will provide references for the collection, breeding and conservation of P.forrestii Schltr..
