A Morphological And Phylogenetic Study On Campylopus Of China

In the present study, based on leaf cross sections and other morphological characters from specimens we collected and literatures about Chinese Campylopus, a total of 16 species of Campylopus were drew and described. A key to identify species of Chinese Campylopus was given. A morphological clustering dendrogram of 18 species of Campylopus was produced by using cluster analysis based on their morphological traits of the collected specimens and those recorded in literature; A molecular phylogenetic study on 16 species of Campylopus was conducted. The molecular data included chloroplast genes: trn L and trn G and nuclear gene: ITS2. Phylogenetic trees were built by using Phyde, PAUP, Mrbayes, and so on. Finally, the genetic diversity and genetic structure of eight populations of Campylopus umbellatus, a species with high morphological variation, were studied based on their ISSR data. Integrating the morphological characteristics and molecular phylogenetic study of Chinese Campylopus,we initially got conclusions as follows:1. 21 species, a variant and a subspecies of Chinese Campylopus in China were confirmed. 16 species of Chinese Campylopus were drew and described, a key to identify species were made. The number of layers, size, shape, density and location of thin-walled and thick-walled cells and the presence of lamellae in the cross section of the costas can be a distinctive feature to distinguish the species of this genus.2. We made a morphological dendrogram of 18 species of Campylopus according to quantitative analysises of their classification characteristics based on the collection of specimens and literatures. The opinion that Chinese Campylopus can be devided in to 4subgenuses(Gao. Q, 1994): Subgen. Pseudocampylopus and the other 3 subgenuses based on the presence of dorsal stereid bands in transverse section, was not rational. Based on12 classification characteristics, 18 species of Campylopus can initially be divided into 3groups;3. According to the topology structure of molecular phylogenetic tree and the supporting values, the following results were obtained:a. The nuclear gene: ITS2 can identify different species of Chinese Campylopus;b. The molecular phylogenetic tree of 16 Campylopus species was established based on ITS2.Chinese Campylopus was a genus of monophyletic origin; Campylopus,Dicranodontium, Dicranum and Leucobryum were sister clads.c. According to the molecular phylogenetic tree of 16 Campylopus species based on ITS2, Campylopus can initially be divided into 3 groups: the group with hyaline point, which is composed of 6 species: C. taiwanensis,C. umbellatus,C. hemitrichum,C. atrovirens,C. schmidii and C. irrigatus; The group without hyaline point, which is composed of 9 species: C. subfragilis, C. caudatus, C. ericoides, C. fragilis, C.zollingerianus,C. pyriformis,C. flexuosus,C.serratus and C. subulatus;There was only1 species: C.schimperi in the group ?. Conduct a phylogenetic study of 16 species of Campylopus according to both morphological and molecular data.The results were identical in general. But a few species like C. schimperi need to be further research. And C. irrigatus Ther. should not be identified as C. japonicus; This species may be the origin of C. taiwanensis and C. umbellatus, which have transparent leaf apex and lamellaes.4. The genetic diversity and genetic structure of 8 populations of Campylopus umbellatus was discussed based on ISSR data. The following results were obtained:a. The results indicated that the populations of Campylopus umbellatus has high level of genetic diversity. The majority of genetic variation(63.33%) exists amongpopulations, which showed that Campylopus umbellatus has o bvious genetic differentiation among populations.b. The dendrogram based on ISSR data showed that 40 samples can be divided into six groups, namely Zhejiang(Populations of Shunxiwu and Liangyuan in Qingliangfeng National Nature Reserve and The population of Yangmei Forestry in Huangyan District), Yunnan(The population of Nabanhe in Xishuangbanna),Guangxi(The population of Shiwan Mountain in Shangsi), Jiangsu(The population of Tianpingshan in Suzhou), Taiwan(The population of Magao Ecological Park in Yilan County) and the Population of Shengsi Islands in Zhejiang Province. We can conclude that the genetic differentiation among the populations of Campylopus umbellatus mainly is caused by geographical factors, while the genetic differentiation in populations may be related to the heterogeneity of the environment where the specieces exist.