Studies On Taxonomy And Flora Of Pottiaceae (Musci) In Inner Mongolia, China

Pottiaceae,which has the largest number of genera in the Bryopsida,is the largest family in Bryophyte in Inner Mongolia.Detailed investigation and research on the flora of Pottiaceae will provide not only basic information to the protection of species diversity but also samples for studying physiology,developmental biology and phylogeny of Pottiaceae.However,there are lot of difficulties in traditional Pottiaceae classification and identification due to intrinsic problems such as polymorphy,taxonomic importance of anatomical charaters,obscure areolation,and sterility of many specimens.With the development of cladistics and molecular systematics,some controversial and tough problems in morphology are increasingly inclined to be resolved through molecular and morphological analysis.Based on the active classification system of the Pottiaceae,the author has conducted the study on the taxonomy of the family by collecting specimens and consulting preserved specimens in the Department of Biology of Inner Mongolia University.According to statistics,28 genera,93 species and 8 varieties of the family are considered to be taxonomically recognizable entitles in Inner Mongolia.Keys to the genera and species,collecting localities and distribution map,herbarium numbers of collection and detailed discussion are given.Detailed morphological description and illustrations are also provided for the new record taxa.In addition,the illustrations of the species are also updated,about which we couldn't find complete data in "Flora Bryophytarum Intramoncolicarum".Among them,2 genera and 9 taxa are recorded new to China:Acaulon,Microbryum,Acaulon triquetrum,Aloina hamulus,Crossidium aberrans,Didymodon hedysariformis,Microbryum davallianum var.conicum,M.starckeanum,Pterygoneurum kozlovii,Syntrichia caninervis var.spuria and Tortula cernua.3 genera and 13 species are reported for the first time from Inner Mongolia:Chenia,Scopelophila,Weisiopsis,Aloina cornifolia,A.brevirostris,Barbula convoluta,B.coreensis,Chenia leptophylla, Hyophila setschwanica,H.spathulata,Scopelophila ligulata,Syntrichia gemmascens, Tortula euryphylla,Trichostomum brachydontium,Weisiopsis anomala and Weissia longifolia.After field investigation,specimen identification and classical taxonomy,an analysis of phylogenetic relationships of the Pottiaceae in Inner Mongolia is presented with the cladistics principles and methods and nucleotide sequence data from the choroplast gene rps4 on the basis of classical taxonomy.Following are the main results:A.Timmiella is near the base of trees and found to be the most primitive extant genus of Pottiaceae by two analysis methods of Cladistics and Molecular systematics.Although Timmiella evinced a full range of characteristic, pleisiomorphic Pottiaceae traits,following development of Molecular systematics,future study may supports the separation of Timmiella from the Pottiaceae.B.The position of Aloina cannot be clarified.Aloina has similar function photosynthetic filaments on the leaf surface of Crossidium and Pterygoneurum,but our morphological and molecular data indicate that Aloina is not closely related with Tortula complex.C.Our data strongly indicate the close relationship of Pseudosymblepharis, Weissia,Trichostomum and Tortella.The above mentioned four genera may actually represent only one genus or belong to the same subfamily.D.Phylogenetic analysis supports a close relationship to Syntrichia,and also proves the separation of Syntrichia from Tortula.E.The phylogenetic relationships within Tortula complex,such as Tortula, Pottia,Phascum,Crossidium and Pterygoneurum,is not clearly resolved.F.The close affinity of Acaulon,Hilpertia and Microbryum is confirmed by our morphological and molecular data.G.Our data suggest that Scopelophila is in the relatively independent and primal postion.All of the analysis show that Weisiopsis is a primal taxa.H.Phylogenetic analysis confirms the monophyly of Didymodon as clearly separated from Barbula.Morphological data imply the close relationship of Anoectangium and Hymenostylium,while molecular data support that of Molendoa,Anoectangium and Hymenostylium.The author conducted a preliminary analysis of the Pottiaceae components.in the Inner Mongolia moss species composition,there are more than nine sepcies of dominant genera,which make up 37.63 percent of the total number.Didymodon is the first major genera,of 18 species,which occupies 17.82%of the total number.The species of Pottiaceae could be grouped into 11 distribution types as Cosmopolitan(11.88%),North Temperate elements(46.54%),Old World Temperate elements(2.97%),Asian and North American elements(8.91%),East Asia elements (10.89%),Pantropical elements(1.98%),Tropical Asian-Tropical American elements(1.98%),Tropical Asian-African elements(0.99%),Tropical Asian elements(0.99%) and Endemic to China(11.88%).The Pottiaceae in Inner Mongolia Autonomous Region shows distinct characteristics of those in Temperate Zone,and the East Asia elements is in the important role.The coefficient of similarity of species shows that the flora of Inner Mongolia is closer to those in Hebei,Xinjiang and Tibet,but farthest to Northeast area.The statistics of geographical distribution indicate that Helan Mountain had the highest species diversity(64.36%),the Northern Yanshan Mountain(52.48%) is second to it,and the lowest diversity appears in Hilly area of Northern YinShan (8.91%).