| Genetic diversity is an integral part of biodiversity and the basis of species and ecosystem diversity.Genetic diversity ensures that species retain their adaptive potential in the long term competition for survival,so it has a great influence on the maintenance of population and the balance and stability of the whole ecosystem.Genetic pattern is the formation of genetic variation in plant population in space and time,which is mainly affected by genetic drift,gene mutation,natural selection and gene flow.The Tirpitzia sinensis is mainly distributed in karst areas,which has medicinal and ornamental value,and is a local endemic species worthy of protection.With Tirpitzia sinensis 14 species(including LiBo(LB),NanDn(ND),CeHeng(CH),SiBing(SB),AnLong(AL),LongLin(LL),WangMo(WM),TianLin(TL),PingBa(PB),ZiYun(ZY),ZhengFeng(ZF),LeYe(LY),NinYun(NY),CangShun(CS))of more than 400 plant as the research object,using microsatellite(SSR)markers for genetic diversity analysis,using biological climate factors on Tirpitzia sinensis in the last interglacial period,the number of the last ice age,middle holocene,and potential distribution area of the modern period of species distribution model simulation,The genetic pattern was analyzed with the composition of soil elements in the sample distribution area.The main results are as follows:(1)SSR analysis results of 14 populations showed that the genetic diversity of population was at an intermediate level(HE=0.509).NJ and UPGMA cluster analysis,according to the results of GuangXi LongLin(LL)only branch populations in the group,as can be seen from the distribution of LL population and GuiZhou sampling population by the NanPan river apart,so probably influenced by hydrothermal conditions or geology,and other sampling of GuangXi population without river apart but there is a certain geographic distance,may be the reason for the genetic distance is too large,the specific differentiation reason need further verification;(2)AMOVA results showed that the genetic variation of Tirpitzia sinensis mainly came from the difference within the population,but the difference between the populations was small.FST estimated that Nm=0.1958,and Nm<1 showed that gene flow was impaired,indicating that genetic drift was the main cause of genetic differentiation in Tirpitzia sinensis population.Testing analysis of each locus,neutral Ewens-Watterson inspection instruction all site survey population was not significant deviation from neutral model,showed that separation,the choice of site and no obvious signs,all known species in the process of evolution is not affected by other factors,not including random factors such as genetic drift,so this study can provide functional genes of excavation with a feasible experiment system.(3)biological species of climatic factor in potential distribution area,according to the results of LL the geographical area in the most appropriate population growth in the last interglacial stage in the modeling area and the last ice age of separation conditions,during the middle holocene temperature recovery appropriate growth area also gradually expanded,the separation distance is narrow,then continue to appear in modern climate modeling separation condition.Climate factor may be one of the reasons for LL population differentiation,but it is only the separation of the optimal growth zone,not the growth zone,so climate factor is not the main reason.(4)Tirpitzia sinensis is mainly distributed in limestone mountains.By measuring the concentration of calcium in the soil samples of the population and analyzing the correlation with the genetic diversity of the population,it is found that the genetic diversity of Tirpitzia sinensis has nothing to do with the content of soil calcium,indicating that calcium is not the reason for the difference in genetic diversity among the populations.In order to explore the relationship between genetic diversity and ecological environment of karst soil,more soil element tests are needed. |
PDF Full Text Request