Genetic diversity of the weed species, Stellera chamaejasme, in China inferred from amplified fragment length polymorphism analysis

Stellera chamaejasme is a perennial weed with a wide geographic range that is found from the Altai of eastern Russia, northern China and Mongolia southwards as far as the western Himalayas of the Qinghai-Tibet and Yungui Plateaus. The genetic diversity and population structure of 17 populations of S.chamaejasme, represented by 349 individuals, were assessed by using amplified fragment length polymorphism markers. The results showed a relatively high level of genetic variation at the species level. The proportion of total diversity among populations was 0.4370, suggesting significant genetic differentiation and a low gene flow among the populations of this species. The Mantel test indicated that genetic differentiation among populations was significantly correlated with geographic distance. Genetic drift through range expansion and a low gene flow among populations might result in a lower diversity in peripheral populations, compared to central populations. A Bayesian analysis revealed two potential gene pools in S.chamaejasme, which was confirmed by neighbor-joining clustering and principal coordinate analysis. These results demonstrate that it is necessary to develop suitable biocontrol agents for populations with different gene pools.