垂珠花自然居群表型性状及遗传多样性分析

Phenotypic Traits and Genetic Diversity of Natural Population of Styrax dasyanthus Perkins

为探索垂珠花自然居群间表型差异的内在因素,该研究用14个表型性状和微卫星分子标记法对6个垂珠花自然居群进行遗传多样性分析。结果表明:(1)14个表型性状在居群间和居群内皆存在极显著差异;居群间平均表型分化系数(V_(st))为22.64%,垂珠花自然居群内的表型变异大于居群间的表型变异,说明居群内变异是垂珠花居群的主要变异来源。(2)4对微卫星引物在87个个体上共检测到43个等位基因,平均每条引物10.63个,平均多态位点百分率(P)为100%;平均观察杂合度(H_o)和平均期望杂合度(H_e)分别为0.659和0.811,Shannon多样性指数(I)平均达1.894;居群内遗传多样性(H_s)高达0.811,居群间遗传多样性(D_(st))仅为0.110,居群间遗传分化系数(F_(st))为0.118,说明11.8%的遗传变异来自于居群间,88.2%的遗传变异来自于居群内,与表型变异研究所得结论大体相一致。表型性状和微卫星分子标记结果均表明垂珠花自然居群存在丰富的遗传变异,较高的基因流(Nm=2.050)使得垂珠花居群间的遗传变异小于居群内的遗传变异。

The object of this work was to explore the intrinsic factors of phenotypic differentiation among natural populations of Styrax dasyanthus Perkins.The genetic diversity of 6 natural populations of S.dasyanthus was analyzed by 14 phenotypic traits and microsatellite markers.The results showed that:(1)there was significant differentiation in 14 phenotypic traits among populations and within population.The mean phenotypic differentiation coefficient(V_(st))was 22.64%, and the phenotypic variation of populations of S.dasyanthus within population was higher than that among populations,which indicated that the phenotypic variation mainly from variance within population.(2)a total of 43 alleles were identified in 87 individuals by 4microsatellite primers,with a mean value of 10.63 alleles per primer and the average percentage of polymorphic loci(P)was 100%.The mean observed heterozygosity(H_o) and expected heterozygosity(H_e),Shannon's information index(I)were 0.659,0.811,1.894,respectively.The genetic diversity within population(H_s)was up to 0.811, and the genetic diversity among populations(D_(st))was only 0.110.The genetic differentiation coefficient(F_(st))among populations was 0.118,indicating that the percentage variation among populations was 11.8%, and the percentage variation within population was 88.2%,which was consistent with the conclusion of phenotypic variation research roughly.The test results of phenotypic traits and microsatellite markers showed that there was abundant genetic variation in the natural population of S.dasyanthus, and the higher genetic flow(Nm =2.050)allowed the genetic variation among populations to be less than that within population.