Intra-species Genetic Diversity Analysis Of Rhodiola Rosea L. Based On Amplified Fragment Length Polymorphism (AFLP) Marker

Rhodiola L., one of the important traditional Chinese herbal medicines, is a perennial herbaceous plant of the family Crassulaceae. Salidroside and tyrosol have been shown to possess the medical functions. In the different environment of growth of Rhodiola L., the level of genetic diversity is high. Intra- and extra-species genetic diversity of Rhodio L. reflects evolution and development to the special entironment. Due to changing consumer demands towards natural health products and the growing interest for unknown plant secondary metabolites and their applications in biotechnology, the natural resource and genetic diversity of Rhodiola L. is on the edge of exhaustion.In our study, Amplified fragment length polymorphism (AFLP) marker was used to analyze the genetic diversity and differentiation of Rhodiola L. in the various populations and attitudes in the south of Tianshan mountains (Xinjiang province). Our aim was to provide the theory of the artificial cultivation, the relationship within the active contents, zone and species. It is available for the conservation and sustainable development. The main results of this study are formulated as follows:1,To establish an AFLP method to analyze the level and change of intra-specific genetic diversity of Rhodiola L. Methods: Genome DNA as template was digested with EcoR I and Mse I by two steps in 25μL reaction system. Ligation was done with T4 DNA ligase at 22℃for overnight. The 50μL pre-amplification reaction mix contains 2.5U Taq plus DNA polymerase, 160μM dNTP, 0.5μM pre-amplification primers each, 4.5μL 10×PCR Buffer(Mg2+). Selective amplification is carried out using 1.5U Taq plus DNA polymerase, 80μM dNTP, 0.25μM pre-amplification primers each, 2.5μL 10×PCR Buffer(Mg2+) and added ddH2O to a 25μL volume.2,Genetic diversity in 12 individuals from three wild populations(the forest farm of Xinjiang Agricultural University, Tianchi Lake, No.1 glacier) were assessed by AFLP marker. The 9 primer combinations generated a total of 214 bands, of which 204 were polymorphic.3,The genetic diversity of Rhodiola L. at the species level is higher than that at the population level. As for wild population at species level, the percentage of polymorphic loci(PPL) was 95.3%, the Nei's gene diversity(H) was 0.266, and the Shannon's information index(I) was 0.420.4,At the population level, the estimates for the wild population PPL=63.7%, H=0.217, I=0.330, Na=1.637 and Ne=1.358.5,Genetic differentiation was high among populations, Gst was 0.185. This means 18.5% genetic variation that occurred between populations. The gene flow(Nm) was 2.199.