Study On The Genetic Diversity Of Rhodiola Sachalinensis Endemic To Changbai Mountain, China

In this paper, ISSR molecular markers were used to analyze the genetic diversityof Rhodiola sachalinensis populations,which from Changbai Mountain NatureReserve and the LaoBaiShan. According to the different altitude, slope and otherdifferent habitats identified12populations, Each population collected10-15individuals. The main contents and conclusions are as follows:(1) Genetic diversity analysis: The total number of bands is380when using12primers for PCR;The percentage of polymorphic loci (PPL) is27%-45%; ThePPL is93.68%at the specie level.In the population level,the averageAo=1.38883,Ae=1.214358,He＝0.1269,I=0.19181; at the specie level, theaverage Ao=1.9368,Ae=1.4520,He＝0.2693,I=0.4114; Shows the R.sachalinensis has a low level of genetic diversity in the populations,and has ahigh level of genetic diversity at the specie.(2) Genetic structure and gene flow analysis: At the specie level the Gst is0.5313,Nm is0.4412, The results revealed that the R. sachalinensis has a obviousgenetic differentiation. Lower gene flow is the important cause leading to thegenetic differentiation. Further the AMOVA results suggested that the geneticdifferentiation among populations occupy a certain position (69.38％amongpopulations and30.62％within populations);The ΦSTis0.694, indicates thatR. sachalinensis has a significant genetic differentiation（p<0.001）.(3) Genetic relationship analysis: The genetic distance of populations are0.0876～0.2999, genetic consistency are0.7409～0.9161. Genetic distance amongN2500-A、N2200-C and N2100-D is below0.20, genetic consistency are in0.80above.,showed a close genetic relationship.；Genetic distance among W2200-H、 W2100-I、W2000-J、ER1-L、ER2-M、TC1-N and TC2-O is below0.20, geneticconsistency are in0.80above.,showed a close genetic relationship.；N2400-Bshowed a close genetic relationship with others except the populations in thenorth slope.(4) Clustering analysis: A UPGMA dendrogram of all sampled R. sachalinensisindividuals was reconstructed. In this dendrogram, all the individuals in a givenpopulation formed a distinct cluster. Clustering results at the population level asthe same result of principal coordinates analysis. There are three clusters:N2500-A、N2200-C and N2100-D clustered together; N2400-B as a cluster;andthe others clustered together.(5) Mantel test showed that the correlation coefficient of vertical distance and geneticdistance r=-0.0799, p=0.0657>0.05; The correlation coefficient of horizontaldistance and genetic distance r=-0.0707,p=0.5000>0.05.showed that there is nocorrelation between the vertical distance,horizontal distance and geneticdistance.Above shows that: The R. sachalinensis has a high level of genetic diversity.,butthe lack of gene exchange between populations. The genetic differentiation is obvious.