Plant Diversity ›› 2017, Vol. 39 ›› Issue (04): 167-179.DOI: 10.1016/j.pld.2017.05.010

• Articles • Previous Articles    

Spatio-temporal evolution of Allium L. in the Qinghai-Tibet-Plateau region:Immigration and in situ radiation

Frank Hauenschilda, Adrien Favrea, Jan Schnitzlera, Ingo Michalaka, Martin Freibergb, Alexandra N. Muellner-Riehla,c   

  1. a Leipzig University, Department of Molecular Evolution and Plant Systematics & Herbarium(LZ), Johannisallee 21-23, 04103 Leipzig, Germany;
    b Leipzig University, Department of Systematic Botany and Functional Biodiversity Research, Johannisallee 21-23, 04103 Leipzig, Germany;
    c German Centre for Integrative Biodiversity Research(iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
  • Received:2017-04-05 Revised:2017-05-31 Published:2021-11-05
  • Contact: Alexandra N. Muellner-Riehl
  • Supported by:
    We thank the German Research Foundation for funding of staff (project no. MU 2934/2-1). We also gratefully acknowledge the support of the German Centre for Integrative Biodiversity Research (iDiv) HalleJena-Leipzig funded by the German Research Foundation (FZT 118) for funding of lab expenses.

Abstract: A plethora of studies investigating the origin and evolution of diverse mountain taxa has assumed a causal link between geological processes (orogenesis) and a biological response (diversification). Yet, a substantial delay (up to 30 Myr) between the start of orogenesis and diversification is often observed. Evolutionary biologists should therefore identify alternative drivers of diversification and maintenance of biodiversity in mountain systems. Using phylogenetic, biogeographic, and diversification rate analyses, we could identify two independent processes that most likely explain the diversity of the widespread genus Allium in the QinghaieTibet Plateau (QTP) region:(1) While the QTP-related taxa of the subgenus Melanocrommyum diversified in situ, (2) QTP-related taxa of other subgenera migrated into the QTP from multiple source areas. Furthermore, shifts in diversification rates within Allium could not be attributed spatially and temporally to the uplift history of the QTP region. Instead, global cooling and climate oscillations in the Quaternary were major contributors to increased speciation rates in three clades of Allium. Our study therefore adds to the growing evidence supporting the "mountain-geo-biodiversity hypothesis", which highlights the role of climate oscillations for the diversification of mountain organisms.

Key words: Allium, Evolution, Hengduan mountains, Historical biogeography, Molecular dating, QinghaieTibet plateau