Genetic Diversity Of Picea Schrenkiana Var.Tianschanica In Different Altitude By EST-SSR Markers Analysis

On the basis of extensive investigations of population structure of P.schrenkiana in different regions and analyzing the dynamic characteristics, we collected and preserved the coniferous materials of the17P.schrenkiana groups from Xinyuan and Fukang, using EST-SSR to make a depth study in the DNA level on genetic structure and genetic diversity of P.schrenkiana in the different altitudes, definiting the degree of change in population structure and genetic diversity of P.schrenkiana resources in different elevations, exploring the geographic distribution and patterns of genetic variation, revealing the structural features and the variation of P.schrenkiana populations at different altitudes, forecasting the development trend, laying the foundation for clarifying the function of P.schrenkiana in mountain ecosystems and germplasm protection and genetic improvement of this important species, and providing a theoretical basis for the healthy development of the Tianshan mountain forest and effectively playing its ecological and economic benefits. The main results are as follows:1. In order to facilitate the collection of coniferous materials of P.schrenkiana and improve the quality of DNA extraction, we invent the treatment method that combine alcohol soaked and silica gel drying. The result shows that soaking P.schrenkiana leaves in ethanol before preserving them in silica gel improved the DNA yield. So, it is recommended that the minimum soak length experimented in this study (24h) can be used.2.10EST-SSR(expressed sequence tag based simple sequence repeat) primer pairs were used to assess genetic diversity of706P.schrenkiana individuals in this study. A total of93putative alleles were generated with a mean of9.3alleles per locus. The percentage of polymorphic loci is100.00%.3.On the species level, Observed number of alleles(A),Effective number of alleles(^e), Shannon’s Information index(I), observed heterozygosity(Ho), expected heterozygosity(He) values were9.3000,3.5663,1.2811,0.4923,0.5907, respectively. The mean of F was0.0846, indicating that the homozygotes of the P.schrenkiana is on the high side. 4. The results of parameters of genetic diversity statistics among populations of the P.schrenkiana show that at the altitude of1700m to2300m range, the genetic diversity of the medium-altitude (2000m) overtop that of the low altitude and high altitude. The altitude of2500m and2600m P.schrenkiana populations also have the same high level of genetic diversity.5. Mean of the coefficient of gene differentiation (GST) of the P.schrenkiana in different sites was0.0755, indicating that7.55%of the total genetic variation existed between groups; gene flow (Nm), an average of6.0948, indicated that the populations existed extensive gene flow; the difference between the FST (0.0902) and GST (0.0755) was very small.6. The results of genetic identity (Ⅰ) and genetic distance (D) of the P.schrenkiana showed that:the difference of the genetic distance (0.0174) between population Xa and Xb was small, and the genetic identity (0.9828) was large, indicating that genetic relationships between that two groups were close; versus, the genetic relationships between Xa and Th were far.7. UPGMA dendrogram sowed that:the populations of the P.schrenkiana depended on altitude to classify to three groups, indicating that populations of the P.schrenkiana in different altitude had variations in the genetic structure.