薇菜SSR分子标记的开发及遗传多样性初步探讨

利用改良FIASCO法(Fast Isolation by AFLP Sequences COntaining repeats)开发出的9对多态性SSR引物评价了薇菜(Osmunda japonica Thunb.)2个野生居群(庐山和恩施)、1个栽培居群(恩施)的遗传多样性和遗传分化水平。结果显示,9个SSR标记在3个薇菜居群中共检测到47个等位基因,每个SSR位点的平均等位基因数为5.222个,观测杂合度和期望杂合度分别为0.000~0.944和0.577~0.834,香农指数为0.962~1.860,表明各SSR位点多态性较高;各居群的平均期望杂合度均大于平均观测杂合度且种内近交系数均为正值,说明3个薇菜居群中都存在非随机交配现象;对各居群的相关遗传多样性参数分析表明,恩施野生居群遗传多样性最高,而其栽培居群最低;庐山野生居群与恩施野生居群间遗传分化系数为0.092,说明两地野生薇菜居群的遗传分化程度较低,AMOVA分析也表明遗传变异主要存在于野生居群内部。

Development of SSR Markers to Assess Genetic Diversity in Osmunda japonica Thunb.

Nine SSR markers developed by a modified FIASCO (Fast Isolation by AFLP Sequences COntaining repeats) method were used to analyze the genetic diversity and differentiation of three Osmunda japonica Thunb. populations,including two wild populations from Lushan and Enshi and one cultured population from Enshi. A total of 47 alleles were detected in the three populations, with a mean N_A(number of alleles) of 5.222. The observed heterozygosity and expected heterozygosity were 0.000-0.944 and 0.577-0.834, respectively. The Shannon index ranged from 0.962 to 1.860. Results suggested that the microsatellite loci were highly polymorphic. For each population, the average expected heterozygosity was higher than that of the observed heterozygosity, and the population inbreeding polymorphism coefficient was positive, indicating the existence of non-random mating. For the three populations, the wild population from Enshi harbored the most abundant genetic diversity, while the cultured population had the lowest. Low levels of genetic differentiation were found between the two wild populations (F_ST＝0.092), which was supported by AMOVA analysis.