J Syst Evol ›› 2021, Vol. 59 ›› Issue (3): 475-489.DOI: 10.1111/jse.12586

• Research Articles • Previous Articles     Next Articles

Phylogenetic analyses confirm polyphyly of the genus Campanula (Campanulaceae s. str.), leading to a proposal for generic reappraisal

Chao Xu1,2 and De-Yuan Hong1*   

  1. 1 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2 College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-12-29 Accepted:2020-03-17 Online:2020-03-20 Published:2021-05-01

Abstract: Previous phylogenetic analyses found that the largest genus in the tribe Campanuleae, Campanula L. is polyphyletic. The genus is extremely intermingled, involving more than 50 genera, but no generic reappraisal has been attempted. For undertaking further phylogenetic analyses and subsequent generic reappraisal of the tribe, we sampled 333 samples, representing 27 of 28 genera currently recognized. Among them, 146 samples and two genera, Cylindrocarpa Regel and Sergia Fed., were newly sequenced. Six chloroplast DNA loci (atpB-rbcL, matK, petD-intron, rbcL, rpl16, and trnL-F) and internal transcribed spacer were used to undertake phylogenetic analyses. Our chloroplast DNA phylogeny comprises 24 clades, that is, 18 Cam clades and six genera, Feeria Buser, Homocodon D. Y. Hong, Jasione L., Peracarpa Hook. f. & Thomson, Trachelium L., and Favratia Feer. Campanula species are scattered among the 18 Cam clades and the six genera, and some of them join with well-established genera like Phyteuma L. and Adenophora Fisch. In the phylogeny Musschia Dumort. is at the basal position, but Jasione's position is unclear, whether in the tribe Campanuleae or in Wahlenbergieae; the other 22 lineages are grouped into two major clades: clade A comprising Cam 13–17 plus Feeria and Trachelium, and clade B comprising Cam 02, 03, 04-1, 04-2, and 06-12 plus Homocodon and Peracarpa. We found that the molecular phylogeny is closely correlated with morphology, particularly pollen morphology: clade A with pollen 3-porate and capsule dehiscent mostly by basal pores; and clade B with pollen mostly 4 (5–15)-porate and capsule dehiscent mostly by apical-middle pores. A generic reappraisal of the tribe is suggested based on the integrated phylogenetic analyses.

Key words: chloroplast DNA, external morphology, generic reappraisal, palynology, phylogenetic analysis, tribe Campanuleae