Spatial genetic structure among and within populations of Primula sieboldii growing beside separate streams
Spatial genetic structure among and within populations of Primula sieboldii growing beside separate streams
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DOI：
10.1111/j.1365-294x.2004.02398.x
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发表时间：
2005-01-01
影响因子：
4.9
通讯作者：
Ohsawa, R
中科院分区：
文献类型：
--
作者：
Kitamoto, N;Honjo, M;Ohsawa, R
我们调查了异柱型克隆草本植物三叶报春（Primula sieboldii）的SSR（simple sequence repeats）和叶绿体DNA（chloroplast DNA）多态性在居群间和居群内的层次遗传结构。母系遗传的cpDNA（Phi = 0.341）的遗传分化程度远高于双亲遗传的SSR（Phi = 0.011）。这一结果表明，溪流之间的种子传播受到限制，花粉是河边种群之间基因流动的主要媒介。与此相反，在两个标记（Phi = 0.053 cpDNA，Phi = 0.025 SSR）流内的亚群之间的遗传分化较低。这种低分化亚群体之间的cpDNA相比，在河边种群表明，种子传播发生沿着流可能在洪水。这一假设是支持的事实，在cpDNA单倍型，没有明确的遗传结构被检测到内的河边人口，而一个显着的遗传结构被发现在20米内的nonstreamside人口。此外，在河边种群内，两对具有相同的8个SSR位点的多位点基因型的分株分布在沿着同一河边，表明克隆繁殖体的扩散。我们的研究表明，景观的异质性可以影响基因流，从而空间遗传结构。
We investigated the hierarchical genetic structure of SSR (simple sequence repeats) and cpDNA (chloroplast DNA) polymorphisms among and within populations of Primula sieboldii, a heterostylous clonal herb. Seven out of eight populations at the study site, located in a mountainous region of Nagano Prefecture, had each developed alongside a different stream, and the other occurred on a flat area 70 m from the nearest stream. The magnitude of genetic differentiation among streamside populations in maternally inherited cpDNA (Phi = 0.341) was much higher than that in biparentally inherited SSRs (Phi = 0.011). This result suggests that seed dispersal among streams was restricted, and pollen was the primary agent of gene flow among streamside populations. In contrast, genetic differentiation among subpopulations within streams were low at both markers (Phi = 0.053 for cpDNA, Phi = 0.025 for SSR). This low differentiation among subpopulations in cpDNA compared with that among streamside populations suggest that seed dispersal occur along the stream probably during flooding. This hypothesis was supported by the fact that in cpDNA haplotypes, no clear genetic structure was detected within the streamside population, while a significant genetic structure was found within 20 m in the nonstreamside population. Furthermore, within the streamside populations, two pairs of ramets with identical multilocus genotypes for eight SSR loci were distantly (> 50 m) distributed along the same streamside, suggesting dispersal of clonal propagule. Our study showed that the heterogeneity of the landscape can influence gene flow and hence spatial genetic structure.