Taxonomic Revision And Biogeographic Study Of Filmy Ferns(Hymenophyllaceae) In China

The filmy fern family(Hymenophyllaceae)is the largest group of basal Leptosporangiate contains over 600 species in 9 genera.Most members of this family are distributed in the tropical and subtropical areas throughout the world,while a few extend to the temperate zone.For the reasons of the vast species and diverse,the intra-family taxonomic system remains controversy.Base on the most recent taxonomic scheme,there are 7 genera of Hymenophyllaceae were recorded in China,but the taxonomic and molecular phylogenetic studies have been rarely reported,and the distribution pattern of domestic species and relationship with nearby countries and areas has never been reported.The present dissertation of taxonomy revision was carried out based on the combination of specimen investigation and field observation,and rbc L molecular phylogeny reconstructed by MP,ML analysis and Bayesian interference.According to the result of taxonomy revision,the distribution characteristics of Hymenophyllaceae in China was analyzed,and the floristic relationship between Chinese species of Hymenophyllaceae and tropical Asia members were discussed.The main results are as follows:1.A new species Crepidomanes shenzhense Hui Wang ? Xiao-yun Wang,has been described.2.23 morphological characters of Chinese filmy ferns' roots,rhizomes,leaves and sorus are selected as the characterization and distinguishment of Chinese taxa.3.Systematic position of China endemic species Vandenboschia fargesii(Christ)Ching is confirmed base on morphological and phylogeny study.4.The taxonomical position of Abrodictyum siamense S.G.Lu ? Hui Wang and Crepidomanes omeiense Ching ? P.S.Chiu are regained at species level respectively.5.The results showed that there are 51 species and 1 variety of Hymenophyllaceae distributed in China,and the provinces with most diverse is Taiwan(40 species and 1variety),the second is Yunnan(23 species and 1 variety),the third is Hainan(21 species).Guangxi,Guangdong,Guizhou,Hong Kong,Sichuan,Xizang,Hunan and Jiangxi contain more than 10 species of Hymenophyllaceae,and Zhejiang,Fujian,Chongqing,Hubei,Anhui,Gansu and Macau contain less than 10 species.6.The flora of Hymenophyllaceae in China is in the north edge of the flora of Hymenophyllaceae in tropical Asia.Most members in China are origenated from tropical Asia.Members in Yunnan,Hainan,Guangxi and Guangdong have closely relationship to members in Indo-China Peninsula,and members in Taiwan have closely relationship to members in Philippines.At the same time,Taiwan also contain many East Asia species that come from China mainland,and that lead to Taiwan has the most diverse of Hymenophyllaceae in China.