Phylogeography of Spiraea alpina (Rosaceae) in the Qinghai-Tibetan Plateau inferred from chloroplast DNA sequence variation

The aim of the present study was to investigate the phylogeographic patterns of Spiraea alpina (Rosaceae) and clarify its response to past climatic changes in the climate-sensitive Qinghai-Tibetan Plateau (QTP).

We sequenced a chloroplast DNA fragment (trnL–trnF) from 528 individuals representing 43 populations. We identified 10 haplotypes, which were tentatively divided into three groups. These haplotypes or groups were distributed in the different regions of the QTP.

Only half the populations were fixed by a single haplotype, whereas the others contained two or more. In the central and eastern regions, adjacent populations at the local scale shared the same haplotype.

Our phylogeographic analyses suggest that this alpine shrub survived in multiple refugia during the Last Glacial Maximum and that earlier glaciations may have trigged deep intraspecific divergences. Post-glacial expansions occurred only within populations or across multiple populations within a local range.

The findings of the present study together with previous phylogeographic reports suggest that evolutionary histories of plants in the QTP are complex and variable depending on the species investigated.

Fig. 1. Map showing locations of the sampled populations of Spiraea alpina and haplotype distribution.
a, Genealogical relationships of haplotypesbased on the trnL–trnF intergenic spacer of the chloroplast (cp) DNA genome.
The diameter of the circles is proportional to haplotype frequency;
verticaldashed lines represent missing intermediate haplotypes.
Different shading of circles indicates different haplotypes and these correspond to the shadedcircles that appear on the map.
b, Map of China showing the Qinghai–Tibetan Plateau.
The map is reproduced with permission from the Data-SharingNetwork of Earth System Science (http://www.geodata.cn, accessed 20 May 2009).

Additional Information:
1 Author Information:ZHANG Faqi, GAO Qingbo, ZHANG Dejun, DUAN Yizhong, LI Yinhu, FU Pengcheng, XING Rui, GULZAR Khan, CHEN Shilong
Correspondence: 　E-mail: slchen@nwipb.cas.cn
2 Publication: Journal of Systematics and Evolution,Volume 50 Issue 4, Pages 276－283.
Published Online: 20 Apr. 2012