A Revision Of Bryhnia And Kindbergia(Brachytheciaceae, Bryophyta) Based On Molecular And Morphological Data

Brachytheciaceae is one of the largest and most controversial families of pleurocarpous mosses. At the beginning of the21th century, the backbone phylogeny of the Brachytheciaceae has been set up. While problems with some particular morphologically similar genera and species still remain. In this study, the phylogeny of the two problematic genera in the family Brachytheciaceae, Bryhnia Kaurin and Kindbergia Ochyra, was conducted based on molecular and morphological data.The morphological investigation was based on more than1000specimens of Bryhnia and Kindbergia, including67type materials belonging to39taxa. With Bryhnia and Kindbergia as the core taxa,98samples belonging to34species and14representative genera of the three subfamilies of the family Brachytheciaceae were used as ingroups for the molecular analyses. Among them,29samples from seven species of Bryhnia and40from four of Kindbergia were included. Barbella flagellifera (Cardot) Nog. and Meteorium atrovariegatum Cardot&Then from Meteoriaceae, the closest relative of Brachytheciaceae, were selected as outgroups. One nuclear and three plastid markers were chosen:nuclear ribosomal internal transcribed spacer region ITS1-5.8S-ITS2(ITS), ribosomal protein L16(rpl16), tRNA (Gly)(UCC)(trnG) and trnL-trnF intergenic spacer (trnL-F). Phylogenetic analyses were performed using Maximum parsimony (MP) and Bayesian inference (BI). The results are as follows:1. Bryhnia is a polyphyletic group.(1) Based on molecular and morphological data, Bryhnia Kaurin was here treated as a synonym of Brachythecium Schimp. Bryhnia novae-angliae, B. hultenii, B. scabrida and B. trichomitria were transferred to Brachythecium. Bryhnia brachycladula was transferred to the genus Myuroclada and further treated as a synonym of the new combination, Myuroclada longiramea (Mull. Hal.) M. Li, Y.F. Wang, M.S. Ignatov&S. Huttunen. Bryhnia graminicolor and B. serricuspis were transferred to the new genera, Bryhniastrum and Pseudokindbergia, respectively.(2) Based on morphological data, Bryhnia pflanzii was transferred to the genus Brachythecium, B. angustifolia and B. tenerrima to Bryhniastrum, and B. polyclada and B. longinervis to Amblystegiaceae.2. A revision of the genus Kindbergia Ochyra(1) Ovate-apiculate or triangular and piliferous pseudoparaphyllia, dimorphic leaves, nearly percurrent costa, horizontal to subpendent capsule, and long-rostrate operculum were re-delimited as the key morphological characters of Kindbergia.(2) Five species have been confirmed in Kindbergia. They are K. arbuscula, K. oregana, K. praelonga, K. squarrifolia and K. stokesii.(3) Kindbergia dumosa distributed in India and Bhutan, and "K. arbuscula","K. praelonga", and B. serricuspis previously reported from China did not fit well in the existing genera molecularly and morphologically. A new monotypic genus, namely Pseudokindbergia, was established for them.3. Taxonomic conclusions:(1) Two new genera have been established. They are Bryhniastrum M. Li&Y.F., Wang and Pseudokindbergia M. Li, Y.F. Wang, B.C. Tan&Ignatov, respectively.(2) Seven new combinations, eight synonyms and one new status are proposed: Brachythecium Schimp., Bryol. Eur.6:5.1853.=Bryhnia Kaurin, Bot.Not.1892(2):[60-]61.1892. syn. nov. Brachythecium hultenii (E.B.Bartram) M.Li&Y.F.Wang, comb. nov.=Brachythecium hultenii var. cymbifolia Nog., J. Hattori Bot. Lab.,8:19.1952. syn. nov. Brachythecium pflanzii (Broth.) M. Li&Y.F. Wang, comb. nov. Brachythecium trichomitria (Dix.&Ther.) M. Li&Y.F. Wang, comb. nov. Bryhniastrum graminicolor M. Li&Y.F. Wang, comb. nov.-Bryhnia angustifolia. Warnst., Hedwigia57:115.50.1915. syn. nov. Bryhniastrum tenerrima (Broth.&Yasuda) M. Li&Y.F. Wang, comb. nov. Myuroclada longiramea (Mull.Hal.) M.Li, Y.F.Wang, M.S.Ignatov&Huttunen, comb. nov.=Bryhnia brachycladula Cardot, Bull. Soc. Bot., Geneve, Ser.2,4:379.1912. syn. nov. Pseudokindbergia dumosa (Mitt.) M. Li,Y.F. Wang, B.C. Tan&Ignatov, comb. nov. Brachythecium novae-angliae (Sull.&Lesq.) A. Jaeger=Bryhnia tokubuchii (Broth.) Paris, index Bryol.(ed.2)1:77.1904. syn. nov. Cratoneuron filicinum (Hedw.) Spruce=Bryhnia polyclada Then, Repert. Spec. Nov. Regni Veg.31:26.1932. syn. nov.=Bryhnia longinervis Then, Repert. Spec. Nov. Regni Veg.31:27.1932. syn. nov. Kindbergia stokesii (Turn.) M. Li&Y.F. Wang, stat. nov.=Kindbergia oedogonium (Mull. Hal.) Ochyra, Beih. Nova Hedwigia88:56.1987. syn. nov.4. Bryhniastrum was characterized by slender plants, ovate-lanceolate to lanceolate leaves and prorate laminal cells, and Pseudokindbergia by bimorphic leaves, semi-orbicular to orbicular-triangular, obtuse or truncate pseudoparaphyllia, inclined to horizontal capsule and conic-apiculate operculum.5. The shape of pseudoparaphyllia, operculum and capsule orientation are reliable morphological characters to resolve genera level relationships in the family Brachytheciaceae.In summary, this study has solved most of the taxonomic problems with Bryhnia and Kindbergia. And the results provide valuable information and methods for allied genera in Brachytheciaceae and other taxa with similiar taxonomic problems.