J Syst Evol

• Research Articles •    

Phylogeny and biogeography of Fagus (Fagaceae) based on 28 nuclear single/low-copy loci

Lu Jiang1,2, Qin Bao1, Wei He1, Deng-Mei Fan1, Shan-Mei Cheng1, Jordi López-Pujol3, Myong Gi Chung4, Shota Sakaguchi5, Arturo Sánchez González6, Aysun Gedik7, De-Zhu Li8, Yi-Xuan Kou2*, and Zhi-Yong Zhang2*   

  1. 1College of Forestry, Jiangxi Agricultural University, Nanchang 330045, China

    2Laboratory of Subtropical Biodiversity, Jiangxi Agricultural University, Nanchang 330045, China

    3Botanic Institute of Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s/n, 08038 Barcelona, Catalonia, Spain

    4Department of Biology and the Research Institute of Natural Science, Gyeongsang National University, Jinju 660-701, Republic of Korea

    5Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 6068502, Japan 6Laboratorio de Ecología de Poblaciones, Centro de Investigaciones Biológicas, Universidad Autónoma del Estado de Hidalgo, Ciudad Universitaria; Carretera Pachuca-Tulancingo Km. 4.5, Mineral de la Reforma 42184, Hidalgo, Mexico

    7Department of Biotechnology, Institute of Natural and Applied Sciences, University of Cukurova, 01330, Adana, Turkey

    8Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China

  • Received:2020-06-07 Accepted:2020-10-04

Abstract: Fagus L. is a key component in temperate deciduous broadleaf forests of the Northern Hemisphere. However, its biogeographic history has not been examined under the framework of a fully resolved and reasonably time-calibrated phylogeny. In this study, we sequenced 28 nuclear single/low-copy loci (18,555 bp in total) of 11 Fagus species/segregates and seven outgroups. Phylogenetic trees were reconstructed using both concatenation-based (ML, MP, BI) and coalescent-based methods (StarBEAST2, ASTRAL). The monophyly of two subgenera (Fagus and Engleriana) and most sections was well supported, except for sect. Lucida, which was paraphyletic with respect to sect. Longipetiolata. We also found a major phylogenetic conflict among North American, East Asian and West Eurasian lineages of subgen. Fagus. Three segregates that have isolated distribution (F. mexicana, F. multinervis, and F. orientalis) were independent evolutionary units. Biogeographic analysis with fossils suggested that Fagus could have originated in North Pacific region in late Early Eocene. Major diversifications coincided with a climate aberration at the Eocene/Oligocene boundary and the global cooling since Mid-Miocene. The Late Miocene accelerated global cooling and the Pleistocene glaciations would have driven beeches into East Asia, North America and West Eurasia. Meanwhile, range reduction and extinction in high latitudes, in central Asia and in western North America converged to form beech modern distribution pattern. This study provides a first attempt to disentangle the biogeographic history of beeches in the context of a nearly resolved and time-calibrated phylogeny, which may shed new insights into the formation of the temperate biome in the Northern Hemisphere.       

Key words: biogeography, nuclear single-copy gene, Fagus, phylogeny, species tree