Plant Diversity ›› 2022, Vol. 44 ›› Issue (02): 153-162.DOI: 10.1016/j.pld.2021.06.006

• Articles • Previous Articles    

Evidence for two types of Aquilegia ecalcarata and its implications for adaptation to new environments

Lei Huang, Fang-Dong Geng, Jing-Jing Fan, Wei Zhai, Cheng Xue, Xiao-Hui Zhang, Yi Ren, Ju-Qing Kang   

  1. National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
  • Received:2021-02-06 Revised:2021-06-17 Published:2022-04-24
  • Contact: Yi Ren,;Ju-Qing Kang,
  • Supported by:
    We thank Li Sun, Xiao-peng Chang for sample collection and other members of Ren's group for technical assistance. We are grateful to Professor Hong-zhi Kong and Professor Song Ge (Institute of Botany, Chinese Academy of Science) for their valuable advice. We also thank professor Elena Kramer (Harvard University) for polishing this manuscript. This work was supported by the National Natural Science Foundation of China (31700180 and 31330007), and the fundamental Research Funds for the Central Universities of Shaanxi Normal University (GK202002011).

Abstract: Spurs have played an important role in the radiation of the genus Aquilegia, but little is known about how the spurless state arose in A. ecalcarata. Here we aim to characterize the genetic divergence within A. ecalcarata and gain insights into the origin of this species. A total of 19 populations from A. ecalcarata and 23 populations from three of its closest relatives (Aquilegia kansuensis, Aquilegia rockii and Aquilegia yabeana) were sampled in this study. We sequenced fifteen nuclear gene fragments across the genome and three chloroplast loci to conduct phylogenetic, PCoA and STRUCTURE analyses.
Our analyses indicate that A. ecalcarata may not be monophyletic and can be divided into two distinct lineages (A. ecalcarata I and A. ecalcarata II). A. ecalcarata I is genetically close to A. kansuensis, whereas A. ecalcarata II is close to A. rockii. Isolation-with-migration analysis suggested that historical gene flow was low between A. ecalcarata I and A. rockii, as well as between A. ecalcarata II and A. kansuensis. The two distinct lineages of A. ecalcarata show significant divergence in 13 floral traits and also have distinct distributions. In addition, both A. ecalcarata I and II are adapted to a stony environment that differs from that of their closest relatives, indicating a habitat shift may have driven new adaptations. Our findings enrich the understanding of how floral evolution contributes to species diversification.

Key words: Aquilegia ecalcarata, Phylogeny, Population structure, Gene flow, Spur loss