Geographic variation of chloroplast DNA in Platycarya strobilacea (Juglandaceae)
Geographic variation of chloroplast DNA in Platycarya strobilacea (Juglandaceae)
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DOI：
10.1111/j.1759-6831.2012.00210.x
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发表时间：
2012-07-01
影响因子：
3.7
通讯作者：
Fu, Cheng-Xin
中科院分区：
文献类型：
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作者：
Chen, Shi-Chao;Zhang, Li;Fu, Cheng-Xin
化香属（Platycarya）是胡桃科（Juglandaceae）的单种属，是东亚分布最广的温带树种之一。本研究利用叶绿体DNA（psbA-trnH和atpB-rbcL基因间间隔区）序列对球果化香树进行了植物地理学研究，以确定该物种主要避难所的位置和迁徙路线。从中国和韩国济州岛的27个居群中采集到180个石藻个体。结果表明，球果马勃在两个基因间隔区上有35种单倍型，遗传多样性较高（hT= 0.926）。这种令人惊讶的高多样性的单倍型表明其漫长的进化历史，这与以前的系统发育分析和化石记录。结果表明，该群体存在明显的地理分化（GST= 0.720; NST= 0.862），表明该群体间通过种子的基因流水平较低，且具有明显的地理分化（NST > GST，P < 0.05）。系统发育关系的构建检测到4个主要的cpDNA分支。BEAST的分歧测年分析表明，主要的cpDNA分支的分歧发生在中新世之前。人口统计学分析表明，东部分支经历了局部的人口扩张。分子系统发育数据，连同单倍型的地理分布，表明存在多个冰川避难所在其目前的范围在中国通过第四纪气候振荡。
The monotypic genus Platycarya (Juglandaceae) is one of the most widespread temperate tree species in East Asia. In this research, we implemented a phylogeographical study using chloroplast DNA (cpDNA) (psbA-trnH and atpB-rbcL intergenic spacer) sequences on Platycarya strobilacea, in order to identify the locations of the species main refugia and migration routes. A total of 180 individuals of P. stobilacea from 27 populations from China and Jeju Island (Korea) were collected. The results revealed that P. strobilacea had 35 haplotypes for the two intergenic spacers and high genetic diversity (hT= 0.926). This surprisingly high diversity of haplotypes indicates its long evolutionary history, which is in agreement with previous phylogenetic analyses and fossil records. Significant cpDNA population subdivision was detected (GST= 0.720; NST= 0.862), suggesting low levels of recurrent gene flow through seeds among populations and significant phylogeographical structure (NST > GST, P < 0.05). The construction of phylogenetic relationships of the 35 chlorotypes detected four major cpDNA clades. Divergence dating analyses using BEAST suggest that the divergence of the major cpDNA clades occurred before the Miocene. Demographic analysis indicated that the Eastern clade underwent localized demographic expansions. The molecular phylogenetic data, together with the geographic distribution of the haplotypes, suggest the existence of multiple glacial refugia in most of its current range in China through Quaternary climatic oscillations.