J Syst Evol ›› 2014, Vol. 52 ›› Issue (3): 289-302.DOI: 10.1111/jse.12089

• Research Articles • Previous Articles     Next Articles

Phylogeography of the Qinghai–Tibet Plateau endemic alpine herb Pomatosace filicula (Primulaceae)

1Gai-Ni WANG 1Xin-Yu HE 2Georg MIEHE 1,3Kang-Shan MAO*   

  1. 1(State Key Laboratory of Grassland Agro-Ecosystem, School of Life Sciences, Lanzhou University, Lanzhou 730000, China)
    2(Faculty of Geography, University of Marburg, 35032 Marburg, Germany)
    3(Key Laboratory for Bio-resources and Eco-environment, College of Life Sciences, Sichuan University, Chengdu 610064, China)
  • Received:2014-01-16 Published:2014-05-09

Abstract: In order to trace the response of alpine plants on the Qinghai–Tibet Plateau (QTP) to the Quaternary climate oscillations, the phylogeographic history of Pomatosace filicula Maxim. was investigated in the present study. Based on sequence variations of two maternally inherited plastid markers, matK and trnH-psbA, and the biparentally inherited nuclear ribosomal internal transcribed spacer (nrITS), we estimated the population genetic structure, lineage divergence timescale, and population dynamics of P. filicula. Seven plastid haplotypes and two nrITS genotypes were identified across the range-wide sampling of 200 individuals from 24 populations. Although AMOVA revealed a high level of differentiation among populations (FST = 0.560), no significant phylogeographic structure was detected (NST = 0.503, GST = 0.518, P > 0.05). Molecular dating suggested that the divergences between major plastid lineages and nrITS genotypes occurred during the early and middle Pleistocene, and the middle Pleistocene, respectively. This species most likely survived at multiple unglaciated sites on the QTP during the Last Glacial Maximum, with most of these sites located above 4000 m a.s.l. The species probably experienced range expansion at its distribution fringe, but demographic tests did not suggest significant population size changes. We proposed that pronounced effective gene flow (Nem = 0.393) and short generation time may have obscured the phylogeographic and demographic patterns of this species. Our findings will shed new light on the Quaternary evolutionary history of the alpine flora of the QTP.

Key words: Pomatosace filicula, Phylogeography, ptDNA, Qinghai-Tibet Plateau, Quaternary.