J Syst Evol

• Research Article •    

New insights into infrageneric relationships of Lonicera (Caprifoliaceae) as revealed by nuclear ribosomal DNA cistron data and plastid phylogenomics

Xu‐Long Yang1,2†, Qing‐Hui Sun3†, Diego F. Morales‐Briones4, Jacob B. Landis5,6, Da‐Juan Chen1, Hong‐Xin Wang1,7, Jun Wen8, and Hua‐Feng Wang1,2*   

  1. 1 Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya 572025, Hainan, China;
    2 Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Agriculture and Crops, Hainan University, Haikou 570228, China;
    3 School of Tropical Medicine, Hainan Medical University, Haikou 571199, China;
    4 Princess Therese von Bayern chair of Systematics, Biodiversity and Evolution of Plants, Ludwig-Maximilians-Universität München, Menzinger Str. 67, Munich 80638, Germany;
    5 School of Integrative Plant Science, Section of Plant Biology and the L. H. Bailey Hortorium, Cornell University, Ithaca 14850, NY, USA;
    6 BTI Computational Biology Center, Boyce Thompson Institute, Ithaca 14853, NY, USA;
    7 Zhai Mingguo Academician Work Station, Sanya University, Sanya 572022, Hainan, China;
    8 Department of Botany, National Museum of Natural History, MRC-166, Smithsonian Institution, P. O. Box 37012, Washington 20013-7012, DC, USA
    Xu‐Long Yang and Qing‐Hui Sun are co‐first authors.*Author for correspondence. E‐mail: hfwang@hainanu.edu.cn
  • Received:2023-01-04 Accepted:2023-07-16 Online:2023-10-10

Abstract: The discontinuous geographic distribution pattern of plants in the north temperate zone has been a focus of biogeographic research, especially concerning the mechanisms behind the formation of such a pattern and the spatial and temporal evolution of this intermittent distribution pattern. Hypotheses of boreotropical origin, land bridge migration, and out-of-Tibet have been proposed to explain the formation of the discontinuous distribution pattern. The distribution of Lonicera shows a typical Europe–Asia–North America discontinuous distribution, which makes for a good case study to investigate the above three hypotheses. In this study, we inferred the phylogeny based on plastid genomes and a nuclear data set with broad taxon sampling, covering 83 species representing two subgenera and four sections. Both nuclear and plastid phylogenetic analyses found section Isika polyphyletic, while sections Nintooa, Isoxylosteum, and Coelxylosteum were monophyletic in subgenus Chamaecerasus. Based on the nuclear and chloroplast phylogeny, we suggest transferring Lonicera maximowiczii and Lonicera tangutica into section Nintooa. Reconstruction of ancestral areas suggests that Lonicera originated in the Qinghai–Tibetan Plateau (QTP) and/or Asia, and subsequently dispersed to other regions. The aridification of the Asian interior may have facilitated the rapid radiation of Lonicera in the region. At the same time, the uplifts of the Tibetan Plateau appear to have triggered the spread and recent rapid diversification of the genus on the QTP and adjacent areas. Overall, our results deepen the understanding of the evolutionary diversification history of Lonicera.

Key words: Caprifoliaceae, Lonicera, nuclear ribosomal DNA cistron, plastid phylogenomics, polyphyletic, section Coeloxylosteum, section Isika