基于核核糖体DNA ITS序列的真藓科系统发育新证据

主要是利用核基因组的核糖体DNA内转录间隔区（nrDNA ITS）序列数据探讨了Buck和Goffinet（2000）限定的真藓科内各属间及属内种间的系统发育关系。ITS序列的最大简约法（MP）及贝叶斯推论（BI）分析结果显示：不支持Cox（1999）利用rps4/trnL-trnF数据分析将丝瓜藓属移至提灯藓科的结论。ITS数据分析与Holyoak（2007）利用trnL-F，trnG和atpB-rbcL序列数据分析将Bryum algovicum、B.caespiticium、B.capillare、B.pseudotriquetrum和Plagiobryum zierii划归Ptychostomum的结论一致，同时，为Spence(2005)依据形态学特征将B.pallescen、B.pallens、B.uliginosum、B.amblyodon和B.lonchocaulon划归Ptychostomum提供ITS分子证据支持。基于以上研究，建议将以上提到的真藓属种和平蒴藓移至Ptychostomum。

New Evidence of Phylogeny in Bryaceae(Musci) Based on the ITS Region

The Bryaceae phylogeny was reconstructed based on the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA. Both Maximum parsimony and Bayesian inference analyses of ITS sequences revealed two well supported ingroup clades. One lineage contained Pohlia species whereas the other lineage contained species from five other genera—Rhodobryum, Brachymenium, Bryum, Plagiobryum and Anomobryum. Inconsistent with previous chloroplast DNA phylogenies, the ITS tree showed that the genus Pohlia was not more closely related to the outgroup family Mniaceae than to Bryaceae. In the other lineage, some Bryum species, such as B.algovicum, B.capillare, B.pallescens, B.pallens, B.pseudotriquetrum, B.uliginosum, B.amblyodon, B.caespiticium and B.lonchocaulon, clustered with high support with Plagiobryum zierii, which was also suggested by other molecular datasets. Based on the ITS tree, we supported the proposed shift for these Bryum species and Plagiobryum zierii to the genus Ptychostomum.