Abstract:Inter simple sequence repeat (ISSR) molecular technique was used to analyze the genetic diversity of 84 Stemona sessilifolia individuals from 4 natural populations.The 15 selected ISSR primers generated a total of 184 fragments,153 of which were polymorphic.Based on results of ISSR analysis,high levels of genetic variation were revealed both at the species level and population level,percentage of polymorphic fragments PPF=83.15%,effective number of alleles (Ae) 1.425,Shannon information index (I) 0.388,and Nei’s gene diversity index (Hpop) 0.254.At population level,PPF=63.04%,Ae=1.351,I=0.310,Hpop=0.206.Analysis of molecular variance (AMOVA) demonstrated that 87.37% of genetic diversity was found within populations.The genetic differentiation coefficient (GST) among populations was 0.191 1.High level of gene flow was found among populations (Nm=2.116 6).The UPGMA cluster analysis and principal components analysis (PCA) revealed that 4 populations formed 2 distinct groups,and taishan population was clearly separated from other populations.However,with S.tubenrosa and S.japonica used as outgroup,the UPGMA cluster analysis supported that S.shandongensis should be treated as a synonym of S.sessilifolia.The Mantel test revealed that an insignificant positive correlation (r=0.625 8，P=0.074) existed between genetic distance and geographical distance.