Research On The Chemical And Genetic Stability Of American Ginseng Successfully Introduced

American ginseng(Panax quinquefolium L.), a perennial herb with root to pass winter, belongs to Panax genus of Araliaceae family. Its root could be a kind of famous traditional Chinese medicine with the complementary property of Asian ginseng(from the plant of P. ginseng C.A.Meyer). American ginseng has been introduced into China more than 30 years, it was researched fully in every aspects when it has been successfully introduced, and it is proved there is not significant differences between the import products and the domestic ones. Although those are right, with the time past there has been some attention to whether the domestic products have changed in the chemical and genetic characteristics. Therefore, in the thesis, Asian ginseng and Canadian ginseng were taken as controls, following to the national GB standard and the "Chinese Pharmacopoeia" requirements, the total ginsenoside and the three kinds of monomer ginsenoside content in the American ginseng roots from our country’s typical origins were compared; and the changes of carbohydrate content; and using RAPD and ISSR molecular technique to analyse its genetic stability. The above indexes are summarized to evaluate the genetic stability in China after the success of the introduction of American ginseng, and to provide a theoretical basis for the optimization of ginseng germplasm resources and the reasonable cultivation.The contents and results in this paper include the following aspects:(1) The content of total ginsenoside and three kinds of monomer ginsenoside in the samples of 13 origins of the American ginseng were determined with UV colorimetric and HPLC(high performance liquid chromatography) methods, the difference analysis and dendrogram construct were carried out with SPSS19.0 software. The results show that, there are two samples do not meet the national standard GB; one sample does not meet the requirements of "China Pharmacopoeia"; clustering results show there is a significant difference between American ginseng and Asian ginseng based on ginsenoside content. American ginseng produced in different areas are divided into three categories, different origin of ginseng ginsenoside components are quite different. Judging from the chemical composition, the introduction of American ginseng in China in general there is no problem, but the quality of stability has been the trend of the problem, so we should strengthen the work of American ginseng varieties selection, in order to ensure the stability of the effective components of the germplasm resources.(2)The total sugar, the reducing sugar and polysaccharide content were detected with UV spectrophotometer method to the collected American ginseng samples of domestic and foreign 13 different habitats, difference analysis and dendrogram constructed based on SPSS19.01 software, and using statistical methods to compare the variation of sugar content of these substances. The results show that the different origin of American ginseng has the remarkable difference in the carbohydrate content; clustering analysis results showed that, different origin of American ginseng can be clustered into four categories; statistical variation analysis of 13 samples of American ginseng is divided into 3 major areas, including the northeast areas of variation is larger, the difference is that with same planting of ginseng a relationship needs further study to determine.(3) Of the above two kinds of chemical components, the correlations of the principal components were analyzed with SPSS19.01 software, and based on those the cluster dendrograms were set up based on the main components content. The results show that the variation coefficient of Rg1, Re, Rb1 and reducing sugar were all above 25%, the variation coefficient of reducing sugar is the maximum. The correlation analysis showed that the cumulative contribution rate of the three principal components is 78.328%; the 13 origins of the ginseng are clustered into four categories with comprehensive clustering.(4) The DNA quality in dried and fresh product of American ginseng were compared with the mass concentration determination and PCR methods, and total genomic DNA was extracted with CTAB method. The results showed that the ratio of OD260/OD280 in the dry products were about 1.8, content of 150-250g/mL, so the products of the RAPD-PCR amplification can be used for downstream molecular biology operation.(5) Total of 13 RAPD primers and 12 ISSR primers were used in the DNA sample PCR amplification, the NTSYS-pc2.10 e software and the method of UPGMA clustering analysis was used according to the band numbers. The results showed that 13 RAPD primers amplified 97 bands, 81 bands were polymorphic, the percentage of polymorphism was 85.51%; 12 ISSR primers amplified 99 bands, 64 bands were polymorphic, the percentage of polymorphism was 64.65%. The clustering analysis showed that, RAPD and RAPD+ISSR integrated the samples were clustered into 4 categories; ISSR samples can be clustered into 2 categories. Sample clustering tree RAPD and ISSR markers are slightly different in classification, but the overall trend is consistent; in ISSR, it is found that Asian ginseng planted together with American ginseng could induce some changes in Asian ginseng. Comprehensive analysis shows that, at present there are some differences between China’s introduction of ginseng in the genetic origin of American ginseng, but it did not reach the quality difference, so it is need to pay more attention to building good breeding field in order to maintain the genetic stability.