Climate oscillation during the Quaternary associated with landscape heterogeneity promoted allopatric lineage divergence of a temperate tree Kalopanax septemlobus (Araliaceae) in East Asia

We investigated the biogeographic history of Kalopanax septemlobus, one of the most widespread temperate tree species in East Asia, using a combined phylogeographic and palaeodistribution modelling approach. Range-wide genetic differentiation at nuclear microsatellites (G′ST = 0.709; 2205 samples genotyped at five loci) and chloroplast DNA (GST = 0.697; 576 samples sequenced for 2055 bp at three fragments) was high. A major phylogeographic break in Central China corresponded with those of other temperate species and the spatial delineation of the two temperate forest subkingdoms of East Asia, consistent with the forests having been isolated within both East and West China for multiple glacial–interglacial cycles. Evidence for multiple glacial refugia was found in most of its current range in China, South Japan and the southernmost part of the Korean Peninsula. In contrast, lineage admixture and absence of private alleles and haplotypes in Hokkaido and the northern Korean Peninsula suppo...

本研究采用联合谱系地理学（phylogeography）与古分布建模的研究方法，探讨了东亚分布最广泛的温带树种之一——刺楸（Kalopanax septemlobus）的生物地理学历史。该物种在核微卫星（nuclear microsatellites）上的全分布区遗传分化水平较高（G'_ST = 0.709；基于5个基因座对2205份样本完成基因分型），在叶绿体DNA（chloroplast DNA）上的全分布区遗传分化水平同样较高（G_ST = 0.697；基于3个片段对576份样本完成2055 bp测序）。华中地区存在的显著谱系地理断裂，与其他温带物种的谱系地理断裂以及东亚两个温带森林亚界的空间分界相吻合，这表明该类森林在多次冰期-间冰期旋回（glacial–interglacial cycles）中于中国东部与西部均发生了隔离。在该物种当前分布的中国大部分区域、日本南部以及朝鲜半岛最南部，均发现了多处冰期避难所（glacial refugia）的证据。与之相反，北海道与朝鲜半岛北部存在谱系混合现象，且缺乏特有等位基因（alleles）与单倍型（haplotypes），这支持...