Taxonomic Study Of HIMOP Complex (Plagiotheciaceae) In China

The morphological differentiations and phylogenetic relationships of Herzogiella Broth., Isopterygiopsis Z. Iwats., Myurella Bruch & Schimp., Orthothecium Bruch & Schimp. and Platydicyta Berk., which part of the updated 8 genera concept of Plagiotheciaceae, are needed to be studied urgently. Although HIMOP complex consisted of these five genera has been considered close to Plagiotheciaceae in recent years, their systematic positions are still in doubt. HIMOP complex species distributed in China are representative and particular. In addition to morphological taxonomy research of types and general specimens, species of these five genera distributed in China and their closely related group’s phylogenetic relationships were studied.The phylogenetic tree based on the nuclear ITS and chloroplast atpB-rbcL, rps4 and trnL-F DNA sequence were performed by the maximum parsimony, maximum likelihood, and Bayesian inference analyses to provide the detailed information to Chinese and the whole world’s Plagiotheciaceae study. The morphological and molecular results suggest:1. By collecting more than 1000 specimens (including 13 types specimens) of the HIMOP complex and related groups, the species of these above five genera in China are confirmed:Herzogiella (2 spp.), Isopterygiopsis (2 spp.), Myurella (3 spp.), Orthothecium (3 spp.) and Platydicyta (2 spp.).2. By the combination of morphological and the related molecular study of all species distributed in East Asia, the results showed that Herzogiella, Isopterygiopsis, Myurella, Orthothecium and Platydicyta are members of Plagiotheciaceae. Myurella, Orthothecium and Platydicyta have a closer relationship than the remaining genera.3. The molecular study reveal that Herzogiella Broth, should be the legal genus name, other than Sharpiella Z. Iwats.. Besides, Herzogiella perrobusta (Broth.) Z. Iwats. and H. turfacea (Lindb.) Z. Iwats. are two independent species. H. perrousta, H. seligeri (Brid.) Z. Iwats., H. turfacea and H. cylindricarpa (Cardot) Z. Iwats. which distributed in South America have a closer relationship than with H. striatella (Brid.) Z. Iwats.. And H. striatella leaves with the distinct decurrent is the significant differences among the genus.4. Fauriella Besch. and Myurella Bruch & Schimp. which was thought of close relationship had been included in Theliaceae. Both of morphological and molecular results showed that Fauriella should belong to Pylaisiadelphaceae as Fauriella clustered with the members of Pylaisiadelphaceae. Thus, Theliaceae which contains only Thelia Sull. is not distribute in Asia.5. Based on the investigation of types and general specimens of which the genus Orthothecium Bruch & Schimp. collected from both domestic and abroad, detailed morphological description, illustrations and a key to the three Orthothecium species distributed in China were provided.6. Twenty five newly provincial records of HIMOP complex species in China were reported.