The Effect Of Human Activities On The Germplasm Of Panax Ginseng

In this study,18 microsatellite markers were developed. Total 13 pairs of SSR primers were used to analyze total 557 Panax ginseng samples.Wild ginseng collected from different areas, half-wild ginseng and cultivated ginseng were compared. Some important results were obtained:1) Based on the sequences of P. ginseng in NCBI. Total 9 pairs of SSR primers for 8 microsatellite sites with steady and clear species-specific productions were obtained to differenciate P. ginseng from P. quinquefolius. Of these primers,7 could amplify special bands to P. quinquefolius and 2 could only amplify bands in P. ginseng. Total 9 pairs of intraspecific polymorphic SSR primers were also developed, amplifying 2-28 alleles with expected heterogeneity (He) from 0.4412 to 0.9171 and observed heterogeneity (Ho) from 0.0357 to 0.6000.2) SSR was used to infer the relationship among different wild ginsengs. Results implied that wild ginseng could be classified as Sichote-alin mountain type and Changbai mountian type. PCA analysis showed that these two types belong to two distinctive clusters, respectively, and significant difference between these two types was found in pairwise FST/RST analysis. In Bayesian analysis, the 4 major genetic components of Sichote-alin mountain type were rare in samples of Changbai mountian type. The normal distribution of genetic diversity (Shannon-Wiener indices) of individuals of these two types was significantly different, centering on 1.2 and 1.5 respectively, implying the Sichote-alin mountain type was genetically unitary in individual level. Interation reallocation showed that 3 refs almost could only be found in Sichote-alin mountain type; ref8, which is an important ref in Changbai mountian type, was rare in Sichote-alin mountain type, and refl was showed in Changbai mountian type but not in Sichote-alin mountain type.3) PCA analysis indicated that Changbai mountain type wild ginseng, half-wild ginseng and cultivated ginseng belonged to the same cluster, and they could be easily distinguished with Sichote-alin mountain wild ginseng. In Bayesian ananlysis, Changbai mountian type wild ginseng and cultivated ginseng were similar in indivdiaul genetic component, and their normal distribution of Shannon Wiener indices centered on 1.4-1.5, which were larger than that of Sichote-alin mountain type wild ginseng. Interation reallocation showed that similar references were found in Changbai mountian type wild ginseng, half-wild ginseng and cultivated ginseng.Those results implyed that cultivated ginseng has had strong influence on wild ginseng in Changbai mountian group. On the contrary, unique genetic resource was preserved in Sichote-alin mountain type wild ginseng. The reasons behind may include:a) The history of planting ginseng is short in Russia and has not been widespread yet; b) Since Sichote-alin mountain is well protected as natural reserve, the wild ginsengs distributed in this area were hardly interrupted by human activity; b) the low-altitude area between Changbai mountain and Sichote-alin mountain blocked most of the cultivated ginseng in China from influencing the germplasm of wild ginseng in Sichote-alin mountain.4) Though different types of cultivated ginseng can be distinguished by morphological characteristics, no significant differences were found among different types in the study. Nevertheless, PCA analysis showed that some individuals of Changbo variance were clustered with other types of cultivated ginseng, half-wild ginseng and Changbai mountian type wild ginseng, while some individuals were clusters with Sichote-alin mountain type, implying Changbo variance may be genetically closer to wild ginseng than other types of cultivated ginseng. And UPGMA tree supported this implication by clustering Changbo variance and Sichote-alin mountain type wild ginseng in the same branch. Bayesian analysis and interation reallocation also showed that Changbo variance is different in genetic membership to other cultivated ginseng.This is the first comprehensive study on the germplasm of different types of ginseng, including wild ginsengs from different distribution areas, different types of cultivated ginsengs and the half-wild ginsengs. The study discovered the strong influence the cultivated ginseng has had on the germplasm of wild ginseng distributed in Changbai mountian. This result will help us on understanding how the ginseng's germplasm be influenced by human's activities, and will provide useful information on protection of ginseng resources and ginseng cultivation.