Studies On Morphology And Molecular Systematics Of Four Genera In Chinese Mniaceae

Minaceae is a very common group of mosses, many of them are gall aphis's midst hosts, which are of significant economic value. However, our knowledge to this group is still limited in various aspects. Different opinions on the circumscription of Minaceae and relationships among different genera also occurs.Classifiction of this family among bryologists mainly follows Kopnen's classification now and its systemists (1981).As we all know, traditional classification is easily affected by environment so there are some limits in traditional classification. Studies on molecular phylogeny on Minaceae have not been reported until now. In this study I focuses on Minaceae's molecular phylogeny , with consideration of morphological analysis. It is really helpful for us to solve taxonomic problems of higher taxa in mosses, improve study level and technique, and establish highlights in bryology.The circumscription of the Minaceae, phylogenetic relationships of genera and its reative were evaluated using morphology and molecular data of rbcL and trnL-F gene of the chloroplast genome.A total of 4 genera and 19 taxa were examined in this study.And some data of Bryaceae were downloaded from Genebank for this analysis. Phylogenetic trees obtained from neighbour jioning and maximum parsimony methods.The results are listed as follows:1.We used gel extraction kit to purify DNA(about 1500 bp) for the first time .The purified DNA can be used in PCR amplification and it got satisfied results.2.In this study we obtained two chloroplast DNA sequences: rbcL and trnL-F. PCR amplification program in a 50μl reaction volume. Taq polymerase was 1u,anneal at 49℃for rbcL, at 52℃for trnL-F.3.In different phylogenetic trees,the species of Plagiomnium always formed a steady clade,the topology supports the viewponit to divide the genus of Plagiomnium for 4 sectios of Kopnen's system.We also suggest that Sectio Rosulata had better put in Sectio Rostrata。4.Based on phylogenetic trees deduced from the sequences of rbcL and trnL-F , we suggest that Mielichhoferia (except for Mielichhoferia macrocarpa)and Pohlia should be placed in the family Minaceae instead of Bryaceae, which supported the viewpoint of Buck & Goffinet (2000).5.According to the phylogenetic analysis of rbcL and trnL-F and morphology characters , the genus of Plagiomnium is more closely to Mnium than to the rest of the Minaceae.6.In this study,the informative sites of rbcL and trnL-F account for 8.7% and 10.7% (>5%) of total length respectively, which indicates reconstruction of Minaceae phylogeny based on rbcL and trnL-F sequence is highly valuable.