Genetic Diversity And Genetic Structure Of Qinling Wild Prunus Tomentosa Thub. Using Simple Sequence Repeats Markers

Prunus tomentosa Thub.（2n=16）originating in China, belong to Subgenuscerasus,Prunus of Rosaceae. Prunus tomentosa Thub. was found mainly in the wild. The distributionarea is wide, north to Heilongjiang province, South to Yunnan province. It has strongadaptability with strong drought and barren resistance. At home and abroad, Prunustomentosa Thub. has better graft compatibility with dwarfing rootstocks of peach and plumthan with sweet cherry. But Wu Xiaogang etc.(2009) tested successfully to use side graftingand insert skin grafting with sweet cherry as scion and Prunus tomentosa Thub. as stock. Theresults showed good affinity. The study researched genetic diversity and genetic structure ofwild Prunus tomentosa Thub. using SSR (Simple Sequence Repeats) molecular markertechnology. The primers was selected from the primers published on peach, apricot and cherryetc. of Prunus. Materials was taken from five valleys in Qinling mountains, located in theTianShui of Gansu province, Huayin of Shaanxi province, Baoji of Shaanxi province, Taibaicounty and Chang’an district of Xi ’an Shaanxi. The research could be benefit for breeding ofpeach, plum and cherry rootstock and expanding their planting range to provide theoreticalbases.Eleven pairs of simple sequence primers were used to analyze genetic diversity andgenetic structure of wild Prunus tomentosa Thub. including104ecotypes,11subpopulations,5populations from Qinling Mountain. The specific findings are as follows：(1) A total of110alleles of11loci were detected from104individuals and5-13allelescould be detected from each primer. The observed average number of alleles (A) was10; theeffective number of alleles (Ae) was7.5863.(2) The percentage of polymorphic loci (PPB) was69.55%in Tianshui Valley,76.53%inChang’an Valley,81.36%in Taibai Valley,85.00%in Huayin Valley,92.17%in MeixianValley, and the total PPB was81.62%.(3) The expected heterozygosity (He=0.8640), the range between0.7964-0.8431,showed wild Prunus tomentosa Thub. had higher lever genetic diversity. About91.88%of(FST=0.0812) gene differentiation was observed within the populations. Geneticdifferentiation within each populations was higher than that among the populations. Based on measured FST, gene flow (Nm) is2.8273.(4) The total Nei’s genetic distance was0.4897and Shannon’s information index is2.1019. Cluster tree based on Nei’s genetic distance revealed that the eleven subpopulationsdivided into three groups. The first group included two subpopulations CA1and CA2ofChang’ an; The second group consisted of two high altitude subpopulations (Tianshuisubpopulatons-TS1and TS2) and two lower altitude subpopulations (Meixiansubpopulations-MX1and MX2); The third group included three high altitude subpopulations(Huayin subpopulations-HY1, HY2and HY3) and two lower altitude subgroup (Taibaisubpopulations-TB1and TB2).