我国的蓑藓属植物形态变异式样复杂,分类问题多。DNA条形码技术是一种新的物种鉴定技术。本研究以采自浙江、福建、云南、广西、四川等省的蓑藓属(Macromitrium)7个物种及其外类群直叶藓Macrocoma tenue sub-sp.sullivantii和火藓Schlotheimia grevilleana的38份标本为对象,获得了它们的叶绿体基因trnL、trnG、psbT和rps4序列,基于这些基因的不同组合构建了15棵贝叶斯系统发育树,获得了相应的蓑藓属植物的物种识别率、种内和种间的遗传距离。发现基于trnL-rps4、trnL-trnG-rps4、trnL-psbT-rps4、trnG-psbT-rps4和trnL-trnG-rps4-psbT等5个组合能够较好地识别本研究中蓑藓属植物,均得到了100%的物种识别率。考虑到扩增和测序的成功率和得到的7种蓑藓属植物的系统发育关系,建议将trnL-trnG-psbT组合用于蓑藓属植物的系统发育分析和物种识别的DNA条形码。
Macromitrium in China has complex morphological variation and many taxonomical problems. DNA barcoding is a new species identification technology. Thirty-eight specimens belonging to Macromitrium gymnostomum Sull. & Lesq., M. ousine Broth., M. taiheizanense Nog., Macromitrium cavaleriei Card. & Ther., M. japonicum Dozy & Molk., M. rhacomitrioides Nog. M. microstomum (Hook. & Grev.) Schw~gr., and Macrocoma tenue subsp, sullivantii and Schlotheimia grevilleana were collected from Zhejiang, Fujian, Yunnan, Guangxi and Si- chuan Provinces. The sequences of four chloroplast genes ( trnL, trnG, psbTand rps4) were sequenced. Fifteen Bayesian phylogenetic trees were made based on different combinations of the above chloroplast genes. Species identification rates, and genetic distances between and within species of Macromitrium in the present study were calculated. We found that combinations of trnL-rps4 , tmL-trnG-rps4 , trnL-psb T-rps4 , trnG-psb T- rps4 and trnL-trnG- rps4-psbTcould be applied to effectively identify Macromitrium species, with 100% species identification rate. Based on the successful amplification and sequencing rate, as well as the phylogenetic relationships among the seven species of Macromitrium, the trnL-trnG-psbT combination was recommended for the DNA barcoding of the genus Macromitrium.