Phylogenetic study of the genus Pohlia (Mielichhoferiaceae, Bryophyta) based on chloroplast DNA sequences

Abstract

The phylogenetic circumscription and taxonomic status of the genus Pohlia in the Mniaceae sensu lato was investigated based on chloroplast DNA sequences (rbcL, rps4, and trnL-F), with a focus on species occurring in Japan. The maximum likelihood and Bayesian inference analyses of sequences obtained from 34 species of Mniaceae s.l., including 13 Pohlia species, suggested that the genus Pohlia and the family Mielichhoferiaceae are not monophyletic in their present circumscription, but confirmed that the family Mniaceae is monophyletic in its traditional sense. These results are congruent with previous molecular phylogenetic studies. Three distinct clades were recognized in the Mielichhoferiaceae, almost corresponding to three sections of Pohlia (Pohlia, Cacodon and Apalodictyon). One of them branched off first within the Mniaceae s.l., and the other two were sister to the remainder of the Mniaceae s.l. The single included Schizymenium formed a monophyletic group with Pohlia sect. Pohlia and Epipterygium with Pohlia sect. Apalodictyon, confirming the results of previous studies. The results indicate that the taxonomic status of the genus Pohlia and family Mielichhoferiaceae are in need of revision. Phylogenetic analyses nested the accessions of P. camptotrachela within P. annotina and P. flexuosa clades, highlighting the need for taxonomic revision of Japanese propaguliferous Pohlia species.