Population differentiation and gene flow within a metapopulation of a threatened tree, Magnolia stellata (Magnoliaceae).
Population differentiation and gene flow within a metapopulation of a threatened tree, Magnolia stellata (Magnoliaceae).
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DOI：
10.3732/ajb.94.1.128
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发表时间：
2007
影响因子：
3
通讯作者：
S. Setsuko;K. Ishida;S. Ueno;Y. Tsumura;N. Tomaru
中科院分区：
文献类型：
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作者：
S. Setsuko;K. Ishida;S. Ueno;Y. Tsumura;N. Tomaru
我们使用 10 个核标记和 3 个叶绿体微卫星（nSSR 和 cpSSR）标记检查了星状木兰集合种群的 8 个当地种群之间的遗传分化，并评估了历史基因流对种群分化的影响。 nSSR 群体间的遗传分化系数 (F(ST) = 0.053) 不到 cpSSR (0.137) 的一半。检测到 nSSR 的按距离隔离模式，但未检测到 cpSSR。这些结果表明，花粉流动以及种子传播显着减少了种群之间的遗传分化。我们还使用 nSSR 标记通过对其中一个群体中的九个种子亲本的种子进行亲子关系分析来检查当代花粉流动的模式，并发现它很大程度上受到亲本之间距离的限制。虽然大部分花粉流发生在种群内部，但来自种群外的花粉流占总量的2.5%。当比较历史和当代人群中的花粉流动时，花粉流动水平最近似乎有所下降。我们的结论是，为了保护 M. stellata，重要的是通过维持其集合种群结构和种群之间的基因流动来保护整个种群。
We examined genetic differentiation among eight local populations of a metapopulation of Magnolia stellata using 10 nuclear and three chloroplast microsatellite (nSSR and cpSSR) markers and evaluated the influence of historical gene flow on population differentiation. The coefficient of genetic differentiation among populations for nSSR (F(ST) = 0.053) was less than half that for cpSSR (0.137). An isolation-by-distance pattern was detected for nSSRs, but not cpSSRs. These results suggest that pollen flow, as well as seed dispersal, has significantly reduced genetic differentiation among populations. We also examined patterns of contemporary pollen flow by paternity analysis of seeds from nine seed parents in one of the populations using the nSSR markers and found it to be greatly restricted by the distance between parents. Although most pollen flow occurred within the population, pollen flow from outside the population accounted for 2.5% of the total. When historical and contemporary pollen flows among populations were compared, the levels of pollen flow seem to have declined recently. We conclude that to conserve M. stellata, it is important to preserve the whole population by maintaining its metapopulation structure and the gene flow among its populations.