Deep genome skimming untangles Adenophora reticulation, redefining Campanulaceae genera

Advances in phylogenomics show that evolution is often a web, not a simple tree: lineages exchange genes through hybridisation and introgression, blurring traditional boundaries between species and even genera. Modern sequencing and bioinformatics make it possible to trace these exchanges across entire genomes rather than a few marker genes.

Adenophora (41–70 species) is a good test case. Although its distinctive “disk” glands between the stamens and pistil set it apart morphologically from other bellflowers, previous molecular studies could not agree on how it relates to neighbouring taxa.

To that end, Dr. Bin-Bin Liu and his colleagues (PhyloAI team) conducted phylogenomic studies using deep genome skimming (DGS) data with their Ortho2Web analysis pipeline, elucidating the crucial role of hybridization and gene flow in the evolutionary history of Adenophora and its allies.

“From 165 samples (48 species and 13 subspecies of Adenophora plus 24 outgroups), we assembled 1,506 single‑copy nuclear genes and 77 plastid coding regions,” shares Liu. “Tree-like phylogenies inferred with both coalescent- and concatenation-based methods revealed extensive conflict among gene trees, and further tests showed that hybridisation—rather than random lineage sorting—explained most of the discordance.”

Integrating genomic, morphological, and geographic evidence, the authors recommend: 1) Expanding Adenophora to include Campanula delavayi and the Korean endemic genus Hanabusaya; 2) Re‑instating Hyssaria as a distinct Central‑Asian genus; and 3) Erecting two new genera, Boreoasia and Rosomala.\

The study was published in the KeAi journal Plant Diversity.

“Our study offers a model for redefining generic delimitation across vascular plants,” adds Liu. “Whole‑genome data let us see the evolutionary web clearly and set taxonomy on a firmer footing.”

Funder:  This research was supported by the National Natural Science Foundation of China (grant numbers 32270216 and 32000163 to B.B.L.), the Youth Innovation Promotion Association CAS (2023086 to B.B.L.), and the Biological Resources Programme, Chinese Academy of Sciences (CAS-TAX-24-013 to B.B.L.).

Journal: Plant Diversity 

DOI: https://doi.org/10.1016/j.pld.2025.05.010

Article title: Phylogenomic insights into Adenophora and its allies (Campanulaceae): Revisiting generic delimitation and hybridization dynamics 

Conflict of interest: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.