Analysis Of Genetic Diversity And Superior Clones Selection In Salix Psammophila Germplasm Resource

Salix psammophila belongs to Salix sp., Salicaceae family. It is a typical mid-xeric deciduous shrub in steppe. And it is an endemic species in China. In order to know genetic variation of Salix psammophila in different original areas and different clones, phenotype diversity, seedling growth traits diversity and SSR marker diversity of Salix psammophila in different original areas were surveyed in this study. Based on the abundant genetic variation of Salix psammophila, superior original areas and superior clones were selected. The main survey results were as follows:1. Salix psammophila from different original areas had significant difference in height and crown range (p<0.01), variation range of crown range was greater than height. The height and crown range of Salix psammophila were in line with normal distribution. Branch colors mostly were red and yellow, followed was gray, purple was the least. The distribution of branch colors in each original area was similar. Bud colors mostly were yellow and brown, black was the least. The distribution of bud colors in each original area wasn't similar.2. There was significant difference in height, ground diameter and survival rate of Salix psammophila from different original areas (p<0.01). Variation range of height was greater than ground diameter of one year Salix psammophila. In contrast, variation range of height was less than ground diameter of one year Salix psammophila. The height and ground diameter growth were realated. The growth of height and ground diameter in the first year was faster than the second year.3. SSR-PCR reaction system was determined on a total volume 25ul system, 12 Salix Psammophila SSR primers were selected. Clones from 9 original areas were amplified by 12 primers. 66 loci were polymorphic in 73 amplified loci of all, with a percentage of 90.4 in total. The average number of amplified loci by each primer was 6.08, and the average polymorphic loci number was 5.5. The number of effective alleles was 1.3266, with a percentage of 68 in total.4. Genetic diversity of Salix psammophila population in 9 original areas was 0.202. The average of genetic diversity in 9 original areas was 0.1712. According to Nei's genetic diversity and Shannon diversity, 9 riginal areas were ranked.5. Based on the two years'cutting experimental results, Harise and Chengchuan were selected to be superior original areas preliminary according to the growth of Salix psammophila. Fast growing superior clones, sturdily superior clones and combinative superior clones were selected too. Fast growing superior clones and sturdily superior clones'selection standard was 30% higher than average value. Combinative superior clones'selection was based on a comprehensive evaluation system established by seedling height,ground diameter and survival rate. Calculated the comprehensive scores of clones, clones which were 30% higher than the average scores were selected to combinative superior clones.