J Syst Evol ›› 2020, Vol. 58 ›› Issue (6): 972-987.DOI: 10.1111/jse.12560

• Research Articles • Previous Articles     Next Articles

Plastome phylogenomic insights into the Sino‐Japanese biogeography of Diabelia (Caprifoliaceae)

Hong‐Xin Wang1 , Michael J. Moore2 , Russell L. Barrett3 , Sven Landrein4 , Shota Sakaguchi5 , Masayuki Maki6 , Jun Wen7*, and Hua‐Feng Wang1*   

  1. 1 Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Life and Pharmaceutical Sciences, Hainan University, Haikou 570228, China
    2 Department of Biology, Oberlin College, Oberlin, OH 44074, USA
    3 National Herbarium of New South Wales, Royal Botanic Gardens and Domain Trust, Sydney, NSW 2000, Australia
    4 Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China
    5 Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606‐8501, Japan
    6 Botanical Gardens, Tohoku University, Sendai 980‐0862, Japan
    7 Department of Botany, Smithsonian Institution, Washington, DC 20013‐7012, USA
  • Received:2019-08-30 Accepted:2019-12-22 Online:2019-12-26 Published:2020-11-01

Abstract:

Understanding the causes of the Sino‐Japanese disjunctions in plant taxa has been a central question in eastern Asian biogeography, with vicariance or long‐distance dispersal often invoked to explain such patterns. Diabelia Landrein (Caprifoliaceae; Linnaeoideae) comprises four shrubby species with a Sino‐Japanese disjunct distribution. The species diversification time within Diabelia, covering a long geological history of the formation process of the Sino‐Japanese flora, dated back to the middle Oligocene, therefore, Diabelia would be an ideal model to elucidate the biogeographic patterns of Sino‐Japanese disjunctions with climate fluctuation. In this study, we analyzed complete plastome sequence data for 28 individuals representing all four species of Diabelia. These 28 plastomes were found to be highly similar in overall size (156 243–157 578 bp), structure, gene order, and content. Our phylogenomic analysis of the plastomes supported a close relationship between Diabelia ionostachya (Nakai) Landrein & R.L. Barrett var. wenzhouensis (S.L. Zhou ex Landrein) Landrein from eastern China and Diabelia spathulata (Siebold & Zucc.) Landrein var. spathulata from Japan. Diabelia serrata (Siebold & Zucc.) Landrein was identified as sister to a population of Diabelia sanguinea (Makino) Landrein from Tochigi in central Japan and D. spathulata Landrein, from Toyama, central Japan. Most Diabelia lineages were estimated to have differentiated 8–28 Mya. Our results indicate that two independent vicariance events could explain the disjunction between Japan and Korea in the mid to late Miocene, and between Zhejiang and Japan in the early Miocene.

Key words: biogeography, Caprifoliaceae, Diabelia, East Asia, phylogenetic relationship, plastome