Contrasts between the phylogeographic patterns of chloroplast and nuclear DNA highlight a role for pollen-mediated gene flow in preventing population divergence in an East Asian temperate tree
Contrasts between the phylogeographic patterns of chloroplast and nuclear DNA highlight a role for pollen-mediated gene flow in preventing population divergence in an East Asian temperate tree
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叶绿体和核 DNA 的系统发育地理学模式之间的对比凸显了花粉介导的基因流在防止东亚温带树木种群分化中的作用
DOI：
10.1016/j.ympev.2014.08.024
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发表时间：
2014-12-01
影响因子：
4.1
通讯作者：
Zhang, Da-Yong
中科院分区：
文献类型：
--
作者：
Bai, Wei-Ning;Wang, Wen-Ting;Zhang, Da-Yong
东亚植物系统地理学研究为生物地理学假说提供了支持，即该地区复杂的地形和气候为异域物种形成提供了大量机会。然而，这些研究大多基于母系遗传的叶绿体DNA （cpDNA）标记，因此无法揭示花粉介导的基因流在防止群体分化中的作用。本文研究了中国核桃（Juglans cathayensis）的系统地理特征。中国核桃是一种温带落叶乔木，广泛分布于亚热带山地。利用7个cpDNA片段和10个核微卫星位点对19个居群进行基因分型，并建立了中国杉树生态位模型。CpDNA分析共鉴定出9个单倍型，19个样本群体中每个群体都固定为一个单倍型，显示出明显的系统地理结构。生态位模拟结果表明，尽管比现在更加破碎化，但在末次冰期时，山核桃种群在原地存活了下来。相比之下，基于核微卫星数据，我们发现了一个更弱但仍然清晰的遗传结构。我们的研究表明，广泛的花粉流可以消除母系长期庇护隔离的遗传印记，有效地防止中国亚热带温带，特别是风媒传粉的森林树木的种群分化。(C) 2014爱思唯尔公司版权所有。
Plant phylogeographic studies in East Asia have provided support for the biogeographic hypothesis that the complex landforms and climate of this region have provided substantial opportunities for allopatric speciation. However, most of these studies have been based on maternally inherited chloroplast DNA (cpDNA) markers and were therefore unable to reveal the role of pollen-mediated gene flow in preventing population divergence. Here, we investigate the phylogeography of the Chinese walnut Juglans cathayensis, a temperate deciduous tree widely distributed across disjunct montane sites in subtropical China. We genotyped 19 populations using seven cpDNA fragments and ten nuclear microsatellite loci and modeled the ecological niche of J. cathayensis. CpDNA analysis identified a total of nine haplotypes, and each of the 19 sampled populations was fixed for a single haplotype, displaying a prominent phylogeographic structure. The results of ecological niche modeling indicated that J. cathayensis populations survived the last glaciation in situ, although they were probably more fragmented than today. In contrast, we detected a much weaker, but nonetheless clear, genetic structure based on nuclear microsatellite data. Our study demonstrates how extensive pollen flow can erase the genetic imprint of long-term refugial isolation in maternal lineages, effectively preventing population differentiation in temperate, particularly wind-pollinated, forest trees in subtropical China. (C) 2014 Elsevier Inc. All rights reserved.