Evaluation Of Rhodiola Sachalinensis A.bor In The Reintroduction Of Changbaishan Medicinal Plant

In this study,the natural wild population and reintroduction population of Rhodiola sachalinensis,a vulnerable medicinal plant in Changbai Mountain,was set as the research object.Samples were collected from the same wild population and reintroduction population in summer from 2017 to 2020.The reintroduction population and the changes in the characteristics of the plant community in the reintroduction area were analyzed.At the same time,changes in the phenological period and morphological characteristics of wild and reintroduction populations of Rhodiola sachalinensis were observed.Using SSR molecular marker technology and SNP molecular marker technology,the genetic structure and single nucleotide polymorphism of wild population and reintroduction population were analyzed.HPLC technique was used to analyze the content of main medicinal components between the wild population and the reintroduction population,and the traditional Chinese medicine fingerprint was established.The results are as follows:（1）The phenotypic characteristics of the reintroduction population were similar to those of the wild population.After the reintroduction population was established,the biodiversity of the plant community in the reintroduction area increased,and the species dominance of the original plant community decreased.The introduction of the reintroduction population had relatively little effect on woody plants,but had a strong competitive relationship with herbaceous plants.（2）The genetic structure of the reintroduction and wild populations of Rhodiola sachalinensis was analyzed by SSR molecular marker technology.The results showed that the percentage of polymorphic loci in the reintroduction population（43.48%）was slightly higher than that in the wild population（39.76%）.The Shannon’s information index（I）of the reintroduction population and wild population were 0.207 and 0.187,respectively.The results of molecular variation analysis（AMOVA）showed that in the reintroduction population and the wild population,the genetic variation within the population（49%）and between-population（51%）were very close.Genetic differentiation（Fst）and gene flow（Nm）indicated that between the two populations the genetic differentiation was rather small（0.070）,while the gene flow was rather large（3.329）.The mantel test was used to analyze the gene flow between the reintroduction population and different wild populations,and the result showed that the gene flow was negatively correlated with altitude and geographic distance.The UPGMA cluster analysis and principal coordinate analysis showed that the reintroduction population and the wild population could be well clustered and the genetic consistency was high,ranging from0.833 to 0.965.（3）SNP molecular marker technology was used to study the single nucleotide polymorphism of UDP-glycosyltransferase,a key functional gene of salidroside synthesis.Through gene fragment tandem analysis,it was found that there are extremely abundant nucleotide polymorphisms and haplotype polymorphisms in both reintroduction population and the wild population.The calculation of genetic distance showed that the genetic distance within the reintroduction population and the wild population was between 0.0194 and 0.0761,and the genetic distance between the populations was between 0.0245 and 0.0343,both of which were rather small.Through UPGMA cluster analysis,it was found that the reintroduction population R and the wild population YS1,which had a closer geographical distance,were clustered into one group,and the other wild populations were clustered into another group.AMOVA analysis showed that 2.74%of genetic variation existed between populations,and 97.26% of genetic variation existed within populations.There was moderate genetic differentiation and large gene flow between the reintroduction population and different wild populations.（4）Using HPLC technology,the contents of salidroside,tyrosol and loxavir in the reintroduction population and wild populations were determined,and the traditional Chinese medicine fingerprint was constructed at the same time.The contents of salidroside and loxavir in the wild population were slightly higher than those in the reintroduction population,and the tyrosol content in the reintroduction population was slightly higher than that in the wild population.The comparison results of the similarity of Chinese medicine fingerprints showed that The similarity of TCM fingerprints between the reintroduction population and the wild population near the altitude in different years is between 0.503～0.926.And the similarity between the reintroduction population and the different wild populations was more than 0.6 in the some year.Through the calculation of Pearson correlation,it was found that the Chinese medicine fingerprint pattern of Rhodiola sachalinensis was significantly correlated with altitude,but not with genetic distance.To sum up,five years after the reintroduction,the reintroduction population is close to the wild population in terms of phenological period,morphological characteristics,genetic diversity,main medicinal components content and Chinese medicine fingerprints.These results enriched the theoretical system of plant reintroduction,and laid a foundation for the protection and population rejuvenation of other rare and endangered plants.