青藏高原及其毗邻山区蒙古绣线菊谱系地理学研究

以青藏高原及其毗邻山区的蒙古绣线菊23个居群324个个体为研究对象,选取叶绿体DNA非编码区trnL-trnF和rps15-ycf1片段对蒙古绣线菊进行谱系地理学研究。结果表明:(1)该研究区域中蒙古绣线菊亲缘关系相近的单倍型多发生于同一居群中,存在着明显的谱系地理学关系。(2)所检测得到的35个单倍型中,大约71.4%是居群内特有的单倍型,而出现频率最高的H1是最古老的单倍型,贝叶斯分析和单倍型简约网状图显示35个单倍型聚为地理分布范围各不相同的3个分支。(3)歧点分布分析得到分布图呈多峰曲线,说明蒙古绣线菊居群在较长的时间内发展稳定,没有经历突然的近期扩张。(4)BEAST分析结果显示,在45Mya左右开始出现蒙古绣线菊的谱系分支的分化。研究认为,蒙古绣线菊在青藏高原及其毗邻山区可能至少存在3个冰期避难所,其在青藏高原及其毗邻山区的分布格局主要是第四纪冰期-间冰期气候动荡、青藏高原隆升的共同作用的结果。

Phylogeography of Spiraea mongolica (Rosaceae) on the Qinghai-Tibetan Plateau and Adjacent Highlands

In the current study,phylogeographic structure of Spiraea mongolica (Rosaceae) was investigated based on cpDNA markers (trnL-trnF and rps15-ycf1).Three hundreds and twenty four individuals distributed in 23 natural populations were used in the study covering the QTP and adjacent highlands.The result showed that:(1)The closely related haplotypes in this study tending to occur in same population indicated significantly phylogeographic pattern within the entire distribution range.(2)About 71.4% of the 35 haplotypes detected from all individuals were endemic in certain population;phylogenetic analysis divided all the haplotypes into three highly supported dades,in which H1 was the more ancient and highly distributed haploptype.(3)Mismatch distribution analysis indicated the species had experienced demographic expansion up to some extent since long time,but the expansion was not so rapid.(4)The results of BEAST analysis revealed that cladistics differentiation of S.mongolica occurred about 45 Mya.This research suggested that there are no less than three glacial refugia of S.mongolica in the QTP and adjacent highlands.The distribution of S.mongolica on the QTP and adjacent highlands was due to the combine effects of climatic instability during quaternary glacial-interglacial episodes and the uplifting of QTP.