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生活史性状和取样策略对植物微卫星遗传多样性参数估算的影响

2016-03-01杜夏瑾黎啸峰吴敏王丽

杜夏瑾 黎啸峰 吴敏 王丽

摘 要 对150种野生种子植物基于微卫星分子标记的遗传参数进行统计,旨在分析植物的生活史性状和取样策略对各遗传参数的影响.结果表明,微卫星标记数与种群遗传分化系数(FST和RST)呈显著正相关,与多样性指数(HO和HE)呈显著负相关;取样距离加大显著提高种群间分化指数FST和RST;种群间分化指数与多样性指数呈显著负相关;异交繁殖、长寿多年生的植物总体上保持着更高的种群内遗传多样性,而自交繁殖的一年生植物具有更高的种群间遗传分化水平;在种群水平上,裸子植物的遗传多样性比被子植物高.

关键词 微卫星标记;简单重复序列;遗传多样性;生活史特征;取样策略

中图分类号 Q944.4 文献标识码 A 文章编号 1000-2537(2015)04-0021-08

Abstract A statistical and comparative analysis of plant genetic diversity parameters was conducted using data from 150 microsatellite-based reports. The results revealed a significant positive correlation between the number of SSR markers and estimates of among-population genetic diversity, but a significant negative association between the former and the estimates of within-population diversity. In addition, an increase in the geographical distances between the sampled populations effectively increases the FST- and RST-values in SSR studies. Estimates for between- and within-population diversity proved to be negatively correlated. The SSR-based analysis showed that outcrossing and long-lived perennial taxa retain most of their genetic variability within populations. By contrast, inbreeding and annual taxa allocate most of the genetic variability among populations. Furthermore, compared with either categories of angiosperm (i.e. monocotyledon and dicotyledon), gymnosperms harbor higher genetic diversity.

Key words microsatellite markers; simple sequence repeat (SSR); genetic diversity; life history traits; sampling strategy

遗传变异是物种长期存在和进化的物质基础.因此,遗传多样性的度量和描述是种群和进化遗传学研究、生物多样性保护和管理中的中心问题.Hamrick, Godt, Nybom, Bartish, Nybom和Duminil等[1-4]的研究表明,植物遗传多样性水平及其遗传结构与物种本身的繁育系统、种子传播方式和分布范围等生活史性状关系密切.合理的取样策略在遗传多样性研究、生物多样性保护和利用中具有重要的意义.取样理论近几十年来被广泛研究[5-8],随着更多的遗传标记的出现,该理论需要不断更新,因为不同的遗传标记和方法所得出的结果有差异,如何在物种保护中合理取样和有效地分析遗传数据也有待完善.

微卫星(microsatellites)亦称简单重复序列(simples sequence repeats, SSRs),由于其……

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