First Insights in the Phylogeny of Asian Cheilanthoid Ferns Based on Sequences of Two Chloroplast Markers

Nucleotide sequences of the chloroplast rbcL and trnL-F regions were determined for 33 Asian species that bear on relationships of the cheilanthoid ferns. Maximum likelihood and Bayesian inference analyses were conducted on separate and combined sequence datasets to gain insights into phylogenetic relationships and generic circumscriptions of these cheilanthoids, with the following results. (1) Doryopteris ludens is always placed far from its congeners. (2) In rbcL sequence analysis, the Old World species of Paragymnopteris K.H. Shing form a strongly supported clade with Pellaea; these taxa are separated into two subclades in phylogenetic trees. (3) Except Paragymnopteris, Doryopteris, and Pellaea calomelanos, all the Asian cheilanthoid species sampled are grouped together and distantly segregated from the American taxa of Cheilanthes, indicating that Cheilanthes sensu Tryon & al. is not monophyletic. (4) The recognition of Sinopteris, Leptolepidium, Cheilosoria, and Mildella is not supported. All Asian species of these four small genera are grouped together with Aleuritopteris in the ML and BI trees.