Genetic Diversity Of Cerasus Tatsienensis (Batal.) Yu Et Li Populations By SSR Markers

C.tatsienensis(Batal.)Yu et Li belonging to Cerasus of Rosaceae is endemic to China and has abundant germplasm resources.It is widely distributed in central and southwestern of China.Its ornamental value and timber processing are very high after being applied.However,due to the deterioration of the natural environment and human damage,the living space of C.tatsienensis has been affected partly.Since there are few systematic studies on the wild resources of C.tatsienensis at home and abroad,to collect and use the wild fine C.tatsienensis resources,and to improve the genetic characteristics of C.tatsienensis are important to carry out a research on the genetic diversity and genetic structure of the population of C.tatsienensis.17 experimental materials from representative groups of C.tatsienensis were collected,total DNA was extracted by CTAB-silica bead method.Then I got 25 pairs of SSR primers,nest it amplified with a 10 ?l PCR system and obtained through an 8% urea-polyacrylamide denaturing gel electrophoresis and silver staining process.GenAlEx 6.502,Popgen 32,NTSYSpc 2.10 e,and Structure were used to analyze the genetic data of C.tatsienensis,and the genetic diversity and genetic structure of C.tatsienensis were analyzed to discuss the internal and external factors which affect their genetic diversity and genetic structure.The main findings are as follows:(1)Genetic diversity of C.tatsienensis: The results of the genetic diversity of 25 SSR markers of 251 individuals from the above 17 populations indicated that: 1)The SSR primer sites of most of C.tatsienensis had deviated from Hardy-Weinberg equilibrium and had reached significant deviation from the level.2)The level of genetic diversity of C.tatsienensis species was high.3)The genetic diversity of 17 populations was at a high level.(2)Genetic structure of C.tatsienensis populations.1)AMOVA analysis of 17 populations of C.tatsienensis showed that the genetic variation among populations accounted for 15%,and the genetic variation within populations accounted for 85%.The genetic variation of C.tatsienensis mainly occurred in its within populations.2)Mantel test of C.tatsienensis showed that the genetic distance and geographical distance of C.tatsienensis populations was r=0.39352,the genetic distance of C.tatsienensis populations was positively correlated with the geographical distance,but the correlation degree was not very obvious.3)The data of 251 tested materials were analyzed by principal coordinate analysis and unweighted pair-group method with arithmetic means.The results of the clustering were consistent: Group? was GMS,SND,DJH,TY and HF populations.Group? was MLZ,XDS,YLXS,YJG,HLG,DLS,ZSX,EMS and YL.Group? was BTM,SWP and HHG.4)According to the STRUCTURE,17 groups of C.tatsienensis were grouped and got data.When K=4,17 populations were divided into 4 gene pools: GroupA was consisted of 5 populations and 3 sub-populations,which were all of GMS,SND,DJH,TY and HF populations in Hubei,1/2 of MLZ in Hubei,1/2 of YL in Sichuan and 1/3 of YLXS in Yunnan.GroupB was consisted of 3 sub-populations,which were all of 1/2 of MLZ in Hubei,4/5 of XDS in Hubei and 1/3 of YLXS in Yunnan.GroupC was consisted of 5 populations and 2 sub-populations,which were all of YJG,HLG,ZSX,DLS and EMS in Sichuan,1/5 of XDS in Hubei,1/2 of YL in Sichuan and 1/3 of YLXS in Yunnan.GroupD was consisted of 3 populations,which were all of BTM in Henan,SWP in Shanxi,HHG in Shanxi.(3)Conclusion.The genetic consistency between DJH,MLZ,XDS,HLG,DLS and other populations was higher,and the genetic distance was closer.These populations were located in central and southwestern of China.There were a large number of individuals in the population and their distribution was extremely widespread.They had more gene flow pathways and higher capacity leading to higher genetic diversity among populations and other populations.The genetic differentiation wasn?t high and the genetic similarity was high.SND,HF,ZSX,HHG and other populations had lower genetic identity and genetic distance.The populations of these populations were small in scale,poorly developed,the gene flow was not easy to produce,the transmission was difficult,the survival rate wasn?t high,and the communication between these populations and other populations was hindered,The genetic diversity declined and the degree of genetic differentiation increased.C.tatsienensis was widely distributed in the southwest,northwest,central and northern of China,especially in Sichuan and Yunnan,where there were a large number of populations and high genetic diversity.It could be speculated that the population in the Hengduan Mountains was the genetic differentiation of C.tatsienensis.The center contained the excellent germplasm resources of C.tatsienensis,especially YLXS population contained more comprehensive genetics.C.tatsienensis germplasm migrated from the genetic differentiation center to the north and east.The geographical distance between Sichuan and Yunnan was relatively close,but lots of large mountains,the complex climate,and the high altitude between the two areas made it difficult to transmit birds and animals,the humidity wasn?t likely to spread the pollen,and the difficulty of genetic exchange among populations was increasing.The genetic exchange was inhibited by the external environment,which resulted in the loss of some genetic genes and a certain degree of genetic differentiation in the population of Sichuan.Hubei,Sichuan and Yunnan were farther apart from each other,mostly in the Daba Mountains,Wushan Mountains,and Wuling Mountains.Hubei populations had genetic differentiation which was inconsistent with Sichuan populations.Because the average elevation of the population in Hubei was low,precipitation and temperature were suitable,so the genetic diversity of the populations were extensive,resulting in a large quantity and high quality and becoming the main population.The population in the northwestern region was HHG,and the populations in north region were SWP and BTM.The three populations were located in the Qinling Mountains and Taihang Mountains,and were geographically located away from the Center of C.tatsienensis.It was very far away,so the lack of gene exchange had led to populations in the northwest and north of China enjoying more independent genetics.In this study,C.tatsienensis is a widely distributed species in China.The genetic diversity of populations is high,the gene exchange among populations is common,there are some genetic variations and the intensity of genetic differentiation isn?t high.The main genetic differentiation comes from the population internal.This paper argues that the Sichuan and Yunnan populations cross the mountains and spread northeastward to the present Wuling Mountains?Wushan Mountains?Daba Mountains?Qinling Mountains?Taihang Mountains.