基于磁珠富集法开发并筛选西川红景天的微卫星标记.

FIASCO magnetic beads method was utilized to develop polymophic SSR markers of Rhodiola alsia, a precious species endemic to the Qinghai-Xizang Plateau. Two SSR marker probes, (AG)15 and (AC)15, were used to construct enriched SSR library and 2 500 positive clones were obtained. Then 1 200 positive clones were randomly selected to check and within which 400 clones were found with polymorphism. Half of the polymorphic clones were randomly chosen for sequencing and 105 SSR loci were achieved. Subsequently, 105 pairs of primers were designed by online software, primer 3-2.3.4, for amplifying the SSR sequences. Among which, a total of 45 pairs of primers were positive for amplification and the sequences amplified by thirteen pairs showed high genetic polymorphism when detected in four far apart natural populations with 24 individuals. Afterwards, the whole of 80 individuals in the four populations were employed to check the thirteen SSR loci. The average number of alleles per locus (A) was around 9.192, the mean of observed heterozygosity (Ho) and the expected heterozygosity (He) were around 0.712 and around 0.734, respectively. Such an extraordinary polymorphism was enough to meet the needs of future research. However, several loci were significantly deviated from Weinberg-Hardy equilibrium (P<0.01) in some populations, which may be due to the fact that the population of the actual study could not reach the ideal state of Weinberg-Hardy's law. Combining SSR polymorphic loci developed previously based on EST (Expressed Sequence Tag)sequences, this study provides a set of serviceable tools for population genetic structure analysis on R. alsia and other researches based on SSR markers. [ABSTRACT FROM AUTHOR]