【作者】 朱永青；

【导师】 王幼芳；

【作者基本信息】 华东师范大学 ， 植物学， 2009， 博士

【摘要】 绢藓科(Entodontaceae)是侧蒴藓类(Pleurocarpous mosses)中一个种类众多、形态复杂多样的大科,在系统演化上与棉藓科(Plagiotheciaceae)、锦藓科(Sematophyllaceae)和灰藓科(Hypnaceae)有着密切的关系。绢藓属(Entodon)是绢藓科中最大的属,占绢藓科种数的84%,全世界约有117种。由于在种级水平上高度的形态变异和种间性状的相互交叉,绢藓属(Entodon)的种间分类一直存在着许多争议。传统上,绢藓属分成两个亚属:Subgenus Entodon和subgenus Erythropus,这种分类方法非常直观,但在缺乏孢子体的情况下,给分类工作带来了许多困难。东亚植物区系是泛北极植物区系中植物种类最丰富和古老的地区,也是世界绢藓属植物两大分布中心之一(另一分布中心为北美南部地区),目前尚未有该地区系统的分类学修订工作。由于研究基础比较薄弱,有些种自发表之后一直无人再研究,因此,部分种的概念也不清楚。已有的绢藓属研究工作主要限于地区性的区系和植物志研究,由于研究标本存在地域性的限制,标本数量有限和研究资料的缺乏,同物异名现象严重。因此,开展东亚地区绢藓属植物的分类学修订和分子系统学研究,对深入研究绢藓属种的界限,种间关系以及分类系统都具有重要的科学意义。东亚地区绢藓属的分类学修订:本研究通过对2000余份普通标本和借阅的104份模式标本进行详细的检视和分类学测量,并结合电镜技术(SEM)观察蒴齿的结构及其表面的纹饰,对东亚地区绢藓属植物进行首次系统的分类学修订,并对属下分类系统和分类上存在争议的种间关系进行讨论。1.在对模式标本的考证和大量普通标本的检视的基础上,确定东亚地区绢藓属植物有33种:E.calycinus,E.challenged,E.chloropus,E.cladorrhizans,E.conchophyllus,E.concinnus,E.curvatirameus,E.divergens,E.diversinervis,E.dolichocucullatus,E.flavescens,E.giraldii,E.kungshanensis,E.longifolius,E.luridus,E.macropodus,E.morrisonensis,E.myurus,E.nepalensis,E.obtusatus,E.plicatus,E.prorepens,E.pulchellus,E.pylaisioides,E.scabridens,E.scariosus,E.schensianus,E.schleicheri,E.smaragdinus,E.sullivantii,E.taiwanensis,E.viridulus,E.yunnanensis。2.提出19个新异名:E.nanocarpus Müll.Hal.= E.challenged,E.zikaiwiensisParis=E.challenged,E.microthecius Broth.= E.challenged,E.buckii S.H.Lin=E.challenged,E.compressus var.parvisporus X.-S.Wen & Z.-T.Zhao = E.challenged,E.verruculosus X.-S.Wen=E.cladorrhizans,E.excavatus Broth.= E.dolichocucullatus,E.punctulatus Thér.& P.de la Varde = E.giraldii,E.diffusinervisCardot = E.luddus,E.tereticaulis Nog.= E.luridus,E.isopterygioides Dixon=E.obtusatus,E.micropodus Besch.=E.prorepens,E.myurus var.hokinensis Besch.= E.prorepens,E.longicostatus W.R.Buck = E.prorepens,E.aeruginosus Mull.Hal.= E.schleichen,E.aeruginosus Mull.Hal.fo.flavescens Mull.Hal.= E.schleicheri,E.purus Müll.Hal.= E.schleicheri,E.acutifolius Hu = Platygyriella aurea,E.schensianus var.denticuspis Dixon=Pleurozium schreberi。3.将2个种从绢藓属中调出:根据蒴柄的颜色和蒴齿的结构,将E.acutifoliusHu调到Platygyriella中,作为P.aurea的新异名,同时P.aurea也作为一个新名(new name)增添到中国藓类植物名录中;根据红色的茎和叶的形态,将E.schensianus var.denticuspis Dixon调到Pleurozium中,作为P.schreberi的新异名。4.在“Index Muscorum”(第二卷)中记载有E.giraldii var.longisetus Müll.Hal.Nuovo Giorn.Bot.Ital.,n.s.3:11.1896,和E.giraldii Müll.Hal.Nuovo Giorn.Bot.Ital.,n.s.4:264.1897,即细绢藓(E.giraldii)发表于1897年,而其变种(E.giraldii var.longisetus)却于1896年发表。通过对原始文献的考证(C Müller1896-1898),没有发现细绢藓这一变种的报道,因此笔者认为E.giraldii var.longisetus Müll.Hal.这个种名不存在。5.可能因标本来源的限制,本研究中尚未发现E.seductrix的相关标本,故暂将E.seductrix从东亚绢藓属植物区系中排除。东亚地区绢藓属的分子系统学研究:本研究共收集500余份绢藓属植物新鲜标本,利用5个DNA片段,包括2个核基因片段(ITS1和ITS2)和3个叶绿体基因片段(trnL intron,trnL-F和trnGintron)重建绢藓属的系统发育关系。研究中成功获得67个绢藓属种类的序列和8个外类群种类的序列,运用最大简约法(MP)对单个基因片段以及多基因联合片段分别构建系统发育树,探讨绢藓属属下分类系统和种间关系。主要结果如下:1.分子分析结果显示,绢藓属是一个单系类群,支持Tsubota等(2001)提出的观点。2.分子数据支持将绢藓属分成两个亚属:Subgenus Entodon和subgenusErythropus,验证了Mizushima(1960)和Buck(1980)提出的属下分类系统。3.Entodon acutifolius Hu一直与外类群种类聚在一起,因此分子数据再一次证明了将Entodon acutifolius Hu调出绢藓属的合理性。本研究是首次对东亚地区绢藓属种类进行传统的分类学修订和现代的分子系统学研究。结合形态学和分子系统学的研究结果,拟形成东亚绢藓属的专著性研究,为世界绢藓属植物研究提供资料。更多还原

【Abstract】 The Entodontaceae is one of the largest pleurocarpus families characterized by diverse sporophytic and gametophytic morphologies.Entodon,the core genus of the Entodontaceae,is a large,cosmopolitan genus,with approximately 117 species globally. Traditionally,the genus was divided into two subgenera:Subgenus Entodon,characterized by mostly complanate-foliation,yellow-green to bright green plants with weekly coata, yellowish seta and exannulated capsules and a usually reddish-brown and striolate exostome;and Subgenus Erythropus,recognized by mostly terete-foliation,dark green with strongly costa,reddish seta and annulated capsules,and a usually and yellow-brown to reddish-brown with densely papillose exostome teeth.However,the specimens of Entodon are commonly sterile,and identification is often difficult because gametophyte characteristics for some species in the genus are not easily defined.It is surprising that no fully resolved relationship among species for this genus.This is the first study to improve both classification and phylogeny,on the basis of morphological and molecular characters.East Asia is one of the centers of distribution of Entodon(the other is northern South America),although the Japanese taxa were revised by Mizushima(1960),the Chinese taxa by Hu(1983),about 100 species were reported from the region.However, on the basis of the online database of eastern Asian mosses "An Introduction to the East Asian Moss Database",just 43 species of Entodon have been accepted.Some species have no any further research since they were established e.g.E.armittii C.Muell.,E.buckii Lin.,E.diffusinervis Card.,E.sinense Dix.,E.luteonitens Ren & Card.,E.nepalensis Miz.,E. ovicarpus Dix.,E.seubertianus Fleisch.,E.subplicatus Ren & Card.,E.toba(e|¨)nsis Fleisch.,and E.verrucubsus Wen.Therefore,further phylogenetic analysis,detailed observations of morphological characters and further discussion were strongly needed.In the present study,the genus in East Asia was taxonomically revised,using more than 2000 specimens,which mainly housed at HSNU and NY,some of which were collected by ourselves,and other borrowed from various herbaria all of the world, including 104 samples of type specimens.Among the morphological observations, special attention is paid to peristome structure by means of the scanning electron microscope(SEM).The relationships among members of this genus were discussed.The main conclusions are as follows:(1).Thirty three species of Entodon are recognized as occurring in the region:E. calycinus,E.challengeri,E.chloropus,E.cladorrhizans,E.conchophyllus,E.concinnus,E. curvatirameus,E.divergens,E.diversinervis,E.dolichocucullatus,E.flavescens,E.giraldii,E. kungshanensis,E.longifolius,E.luridus,E.macropodus,E.morrisonensis,E.myurus,E.nepaknsis, E.obtusatus,E.plicatus,E.prorepens,E.pulchellus,E.pylaisioides,E.scabridens,E.scariosus,E. schensianus,E.schleicheri,E.smaragdinus,E.sullivantii,E.taiwanensis,E.viridulus,and E. yunnanensis.(2).Nineteen species of Entodon are newly treated as synonyms of other species: Entodon nanocarpus Müll.Hal.= Entodon challengeri,Entodon zikaiwiensis Paris = Entodon challengeri,Entodon microthecius Broth.= Entodon challengeri,Entodon buckii S.H.Lin = Entodon challengeri,Entodon compressus var.parvisporus X.-S.Wen & Z.-T.Zhao = Entodon challengeri,Entodon verruculosus X.-S.Wen = Entodon cladorrhzans,Entodon excavatus Broth.= Entodon dolichocucullatus,Entodon punctulatus Thér.& P.de la Varde = Entodon giraldii, Entodon diffusinervis Cardot = Entodon luddus,Entodon tereticaulis Nog.= Entodon luridus, Entodon isopterygioides Dixon = Entodon obtusatus,Entodon micropodus Besch.= Entodon prorepens,Entodon myurus var.hokinensis Besch.= Entodon prorepens,Entodon longicostatus W.R. Buck = Entodon prorepens,Entodon aeruginosus Müll.Hal.= Entodon schleicheri,Entodon aeruginosus Müll.Hal.fo.flavescens Müll.Hal.= Entodon schleicheri,Entodon purus Müll.Hal. = Entodon schleicheri,Entodon acutifolius Hu = Platygyriella aurea,and Entodon schensianus var. denticuspis Dixon = Pleurozium schreberi(3).Four species of Entodon are excluded from this genus of this region:Entodon acutifolius Hu transferred to Platygyriella aurea;Entodon schensianus var.denticuspis Dixon transferred to Pleurozium schreberi,Entodon giraldii var.longisetus Müll.Hal.,I am unable to find the original description and original specimens;Entodon seductrix(Hedw.) Mull.Hal., I have been unable find material referred to E.seductrix in the study region. Phylogenetic relationship among the species of Entodon were also investigated.Five genomic regions,two from the nuclear genome(ITS1 and ITS2),and three from the chloroplast genome(trnL intron,trnL-F,and trnG intron).About 500 fresh specimens of this genus in the region were obtained and examined.Nucleotide sequences were determined in 67 species of Entodon and eight outgroup species,the chosen Entodon species represented the majority of those found in East Asia.Phylogenetic trees were constructed by the maximum-paesimony(MP) method,based on individual region and combined regions analysis.The results indicate that(1) the genus Entodon is a monophylous;(2) the genus Entodon could be separated into two subgena,which are identical to the research results of Mizushima(1960) and Buck(1980) on the basis of the morphological characters;(3) Entodon acutifolius is best excluded from the genus Entodon.This is the first significant study of the genus Entodon in East Asia in which both morphological and molecular characters were increased.Through this study,a monograph of Entodon in East Asia is expected to compile,which may provide detailed information for bryophyte research throughout the world.更多还原