Plant Diversity ›› 2024, Vol. 46 ›› Issue (05): 585-599.DOI: 10.1016/j.pld.2024.04.008

• Articles • Previous Articles    

Genetically-and environmentally-dependent processes drive interspecific and intraspecific divergence in the Chinese relict endemic genus Dipteronia

Tao Zhoua,b, Xiaodan Chenc, Jordi López-Pujold,e, Guoqing Baif, Sonia Herrando-Morairad, Neus Nualartd, Xiao Zhangf, Yuemei Zhaog, Guifang Zhaoa   

  1. a. Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Sciences, Northwest University, Xi'an 710069, China;
    b. School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China;
    c. College of Life Science, Shanxi Normal University, Taiyuan, China;
    d. Botanic Institute of Barcelona (IBB), CSIC-CMCNB, Barcelona 08038, Catalonia, Spain;
    e. Escuela de Ciencias Ambientales, Universidad Espíritu Santo (UEES), Samborondón 091650, Ecuador;
    f. Shaanxi Engineering Research Centre for Conservation and Utilization of Botanical Resources, Xi'an Botanical Garden of Shaanxi Province, Xi'an 710061, China;
    g. School of Biological Sciences, Guizhou Education University, Guiyang, China
  • Received:2023-09-26 Revised:2024-04-15 Published:2024-09-07
  • Contact: Guifang Zhao,E-mail:gfzhao@nwu.edu.cn
  • Supported by:
    Special thanks to Cindy Q. Tang for providing information on the occurrence of Dipteronia. This study was co-supported by the National Natural Science Foundation of China (Grant No. 31470311) and the Ph.D. Programs Foundation of the Ministry of Education of China (Grant No.20136101130001).

Abstract: China is a hotspot of relict plant species that were once widespread throughout the Northern Hemisphere. Recent research has demonstrated that the occurrence of long-term stable refugia in the mountainous regions of central and south-western China allowed their persistence through the late Neogene climate fluctuations. One of these relict lineages is Dipteronia, an oligotypic tree genus with a fossil record extending to the Paleocene. Here, we investigated the genetic variability, demographic dynamics and diversification patterns of the two currently recognized Dipteronia species (Dipteronia sinensis and D. dyeriana). Molecular data were obtained from 45 populations of Dipteronia by genotyping three cpDNA regions, two single copy nuclear genes and 15 simple sequence repeat loci. The genetic study was combined with niche comparison analyses on the environmental space, ecological niche modeling, and landscape connectivity analysis. We found that the two Dipteronia species have highly diverged both in genetic and ecological terms. Despite the incipient speciation processes that can be observed in D. sinensis, the occurrence of long-term stable refugia and, particularly, a dispersal corridor along Daba Shan-west Qinling, likely ensured its genetic and ecological integrity to date. Our study will not only help us to understand how populations of Dipteronia species responded to the tectonic and climatic changes of the Cenozoic, but also provide insight into how Arcto-Tertiary relict plants in East Asia survived, evolved, and diversified.

Key words: Dipteronia, Interspecific/intraspecific divergence, Genetic structure, Climatic niche divergence, Dispersal corridor