[关键词]
[摘要]
目的 基于广西地不容转录组序列开发SSR引物,并用于该物种自然居群遗传多样性的研究。方法 从广西地不容转录组测序获得的unigene序列中挖掘SSR位点,采用Oligo 7.0软件设计引物,通过电泳法筛选得到多态性高的SSR引物用于遗传多样性研究。结果 从广西地不容转录组20 637条unigene序列中,搜索到6 833个SSR位点,出现频率为33.11%。基于转录组序列设计50对引物,筛选得到10对多态性高的引物。10对引物在5个居群63个样本中共扩增得到83个条带,有效条带百分率为100%,多态性信息量(PIC)为0.688 9。在物种水平和居群水平上,Nei基因多样性指数(H)分别为0.725 2和0.613 4,Shannon多样性指数(I)分别为1.576 6和1.220 3,观察杂合度(Ho)分别为0.584 5和0.558 4,期望杂合度(He)分别为0.731 2和0.643 5。居群的遗传分化系数(Fst)为0.146 5,基因流(Nm)为1.456 9。UPGMA聚类分析表明,5个居群可分为3支系。结论 开发的SSR标记适用于广西地不容的遗传多样性分析。广西地不容在物种和居群水平上均具较高的遗传多样性,遗传分化主要存在于居群内部。
[Key word]
[Abstract]
Objective To develop simple sequence repeat (SSR) molecular markers based on Stephania kwangsiensis transcriptome and to evaluate genetic diversity of S. kwangsiensis in natural populations. Methods The unigenes from S. kwangsiensis transcriptome were used to explore SSR loci. SSR primers were designed by oligo 7.0. Polymorphic primers were selected by electrophoresis and were applied to the investigation of the genetic diversity of S. kwangsiensis. Results A total of 6 833 SSR loci (33.11%) were obtained from 20 637 unigenes in the S. kwangsiensis transcriptome. Of the 50 SSR markers tested, ten pairs of highly polymorphic primers were selected to analyze the genetic polymorphisms of 63 individuals from five populations. Ten primers produced 83 band loci, all (100%) of which were polymorphic, and the polymorphism information content (PIC) was 0.688 9. At the species level and population level, the Nei's gene diversity (H) was 0.725 2 and 0.613 4, respectively; the Shannon's Information index (I) was 1.576 6 and 1.220 3, respectively; The observed heterozygosity (Ho) was 0.584 5 and 0.558 4, respectively; The expected heterozygosity (He) was 0.731 2 and 0.643 5, respectively. The genetic differentiation coefficient (Fst) was 0.146 5 and the gene flow (Nm) was 1.456 9. Based on UPGMA cluster analysis, the five populations of S. kwangsiensis were divided into three clusters. Conclusion The developed SSR markers were applicable to the genetic diversity evaluation of S. kwangsiensis. The genetic diversity of this plant was relatively high at both species level and population level. The genetic differentiation mainly existed within populations.
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[基金项目]
国家自然科学基金项目(31100238)