Recent colonization by a coastal plant of inland habitats at an ancient freshwater lake, Lake Biwa : multilocus sequencing and a demographic history of Lathyrus japonicus (Fabaceae)
Recent colonization by a coastal plant of inland habitats at an ancient freshwater lake, Lake Biwa : multilocus sequencing and a demographic history of Lathyrus japonicus (Fabaceae)
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最近，一种沿海植物在古代淡水湖琵琶湖的内陆生境中定植：山黧豆（豆科）的多位点测序和种群历史
DOI：
10.1002/ece3.654
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发表时间：
2013
影响因子：
2.6
通讯作者：
H.
中科院分区：
文献类型：
--
作者：
Ohtsuki;T.;Ikeda;H.;Setoguchi;H.
古湖泊被认为是陆地生态系统中的“长期孤岛”。琵琶湖是大约400万年前形成的少数几个古老湖泊之一，拥有许多通常栖息在海岸的沿海物种。海滩豌豆，山豌豆，是一个典型的沿海物种的淡水湖，在形态，生理和遗传分化已被报道之间的琵琶湖和沿海人口。在整个更新世的气候振荡和随后的范围转移中，琵琶湖种群是否长期孤立尚不清楚。利用8个核基因座的序列对古淡水湖中的海滩豌豆进行了群体遗传结构和种群统计学分析。结构分析的结果表明，证据的混合物之间的琵琶湖和沿海人口，反映了最近的基因流。估计的人口参数实施的隔离与迁移模型（IM模型）揭示了最近的分歧（冰后期）的琵琶湖人口，与一些基因流从琵琶湖沿海人口。此外，琵琶湖种群的规模明显小于祖先或沿海种群。我们的研究表明，全新世热最大时，海侵可以让种子从沿海植物进入琵琶湖，参与了起源的琵琶湖人口和他们的遗传分化。因此，沿海人口可能是最近才迁移到琵琶湖的。我们的研究得出结论，琵琶湖的祖先移民来自小的创始种群，并在短期隔离期间加速了琵琶湖种群的遗传隔离。
Ancient lakes have been recognized as “long‐term isolated islands” in terrestrial ecosystems. Lake Biwa, one of the few ancient lakes that formed around 4 million years ago, harbors many coastal species that commonly inhabit seashores. The beach pea,Lathyrus japonicus, is a typical coastal species of this freshwater lake, where morphological, physiological, and genetic differentiations have been reported between Biwa and coastal populations. Whether Biwa populations were isolated for long periods throughout Pleistocene climatic oscillations and subsequent range shifts is unclear. We assessed population genetic structure and demography of beach pea in this ancient freshwater lake using the sequences of eight nuclear loci. The results of STRUCTURE analyses showed evidence of admixture between Biwa and coastal populations, reflecting recent gene flow. The estimated demographic parameters implemented by the isolation with migration model (IM model) revealed a recent divergence (postglacial period) of Biwa populations, with some gene flow from Biwa to coastal populations. In addition, Biwa populations were significantly smaller in size than the ancestral or coastal populations. Our study suggests that a Holocene thermal maximum, when transgression could allow seeds from coastal plants to access Lake Biwa, was involved in the origin of the Biwa populations and their genetic divergence. Thus, coastal populations might have migrated to Lake Biwa relatively recently. Our study concluded that ancestral migrants in Lake Biwa were derived from small founding populations and accelerated genetic isolation of Biwa populations during short‐term isolation.