Genetic Diversityanalysis Of Salix Psammophila Germplasm Resource By SSR Molecular Markers

Salix psammophyla belongs to salicaceae. It is a perennial shrub with high product and feed value etc,Which is the pioneer plant of wind-breaking and sand-fixing.In this study,using SSR markers were used to detected genetic diversity and relationship among 9 populations of Salix psammophyla which were collected from different producing area.The objectives of this study are to provide basis for Salix psammophyla genetics and breeding research.The results showed as follows:1 Using the L₂₅(5⁵)table of Orthogonal ,study on the SSR-PCR reaction condition,An optimization system of SSR markers was established,which the 25μl PCR recation buffer consisted of DNA 90ng,primer 1.2μmol/L,dNTP 0.5mmol/L,10×buffer 6.25μM,1.5U TaqDNA polymerase.SSR-PCR was programmed with an initial denaturing at 94℃for 2min,followed by 30 cycles of 94℃for 40s,54℃for 1min and 72℃for 2min, preserved at 4℃。2 For genetic diversity analysis,A total of 73 distinct bands were detected with 12 SSR primers among 9 populations,63 bands were polymorphic,Percentage of polymorphic loci can reach 86.3%,The variation ranged from 2 to 18 bands with an average of 6.1;The PIC ranged from 60.%27 to 72.60% with an average of 66.36%.Shannon′s index ranged from 0.2382 to 0.2934 with an average 0.2687.3 Nine populations were divided into 2 groups at similarity coeffcient being 1.8301 by applying UPGMA for clustering analysis of them.The results of cluster analysis based on SSR data indicated that the gene pool of germplasm of Salix psammophyla was relatively narrow because the genetic similarity(GS) ranged from 0.9318 to 0.9846.4 The genetic similarity cofficient between Salix psammophila clone by genotype with the results showed genetic similarity cofficient of clones is 89% from MenKeQin population in YiJinHuoLuoQi,It is obviously lower than other populations and it has the potential of provenance of seedlings selecting and breeding .The genetic similarity cofficient of clones groups less than 64% are 4 and 2 from ChaHanNaoEr population and HuLaHuShe in WuShenQi with its has the potential of selection breeding .