Conservation Genetics Of Tetraena Mongolica And Development Of Microsatellite Genetic Markers For Three Endangered Plants In West Ordos Plateau

West Ordos National Nature Reserve is located in the Inner Mongolia Autonomous Region,because of its unique climate,topography,landforms,etc.,making it become a place where a lot of rare animals and plants live there as a "refuge." In this study,four national endangered protected plants were selected,namely Tetraena mongolica,Amygdalus mongolica,Ammopiptanthus mongolicus and Tugarinovia mongolica.Among them,Tetraena mongolica and Tugarinovia mongolica are the national grade I protected wild plant,Amygdalus mongolica and Ammopiptanthus mongolicus both are national grade II protected plants.This study is mainly divided into two sections,on the one hand,it provides an important scientific basis for the genetic protection of Tetraena mongolica population through microsatellite molecular markers to study its genetic diversity,genetic structure,population history and other aspects.On the other hand,through high-throughput sequencing,SSR microsatellite loci were developed for three species of Amygdalus mongolica,Ammopiptanthus mongolicus and Tugarinovia mongolica.Based on the analysis of 339 Tetraena mongolica samples refer to the genetic diversity and genetic structure that calculate by microsatellite.The results are as follows:(1)The analysis of genetic diversity showed that the average number of alleles ranged from 13.17 to 17.67,the locus richness ranged from 6.860 to 10.529,the observed heterozygosity ranged from 0.810 to 0.873,the expected heterozygosity ranged from 0.832 to 0.882.This shows that Tetraena mongolica population has high genetic diversity.(2)Analysis of population genetic structure:The genetic distance ranged from 0.00034 to 0.04284,and most of them were significantly supported(P<0.05),indicating that the genetic differentiation among the eight geographical populations was extremely weak.Cluster analysis and correlation analysis showed that all the populations were highly overlapped,which was consistent with the result of genetic distance.Therefore,the eight geographical populations of Tetraena mongolica should be treated as a whole unit of protection and thus be protected.Through high-throughput sequencing,SSR microsatellite loci were carried out on three species of Amygdalus mongolica,Ammopiptanthus mongolicus and Tugarinovia mongolica.The results are as follows:(1)A total of 51 pairs of polymorphic loci were developed in Amygdalus mongolica,with the number of effective alleles ranging from 13 to 25,the observed heterozygosity ranged from 0.875 to 1.000,and the expected heterozygosity ranged from 0.863 to 0.946.Polymorphism information was from 0.854 to 0.943.These locis can be used as a reliable molecular marker for genetic strcture of Amygdalus mongolica population.(2)Ammopiptanthus mongolicus has successfully developed 20 pairs of microsatellite loci with high observed heterozygosity and expected heterozygosity in the range of 0.500-1.000 and 0.447-0.844,respectively.The PIC ranged from 0.374 to 0.807,indicating that these loci are highly polymorphic and do not show linkage disequilibrium among loci.(3)Tugarinovia mongolica successfully developed 21 pairs of microsatellite loci,the range of observed heterozygosity was from 0.083 to 1.000,the range of expected heterozygosity was from 0.156 to 0.965.