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1.
老鸦瓣群(Amana群)是百合科中的一个东亚特有类群,仅分布在中国中东部、日本和朝鲜半岛。该类群在形态上与广义郁金香属Tulipa L.相似,但也具有与子房近等长的花柱以及2-3(-4)个苞片等与郁金香属不同的形态特征。有关该类群是否应置于郁金香属中或是否应独立为属的问题长期以来存在争议。为了澄清该问题,我们对产于中国的Amana群进行了广泛的标本室和野外形态观察,并采用分支系统学方法,对该类群3个种以及郁金香属的其他15种植物(包括土耳其的3个种)的28个形态性状数据进行了分支分析。结果表明广义郁金香属并非是一个单系类群。Amana群与广义郁金香属的其他4个组sect. Orithyia、sect. Eriostemones、sect. Leiostemones、sect. Tulipanum以及Lloydia属的两个种共同构成一个大支的3个分支。我们对广义郁金香属5个组共19种植物的ITS以及trnL-F分子序列综合分析的结果也表明:sect. Tulipanum、sect. Leiostemones、sect. Eriostemones和sect. Orithyia构成一大支,Amana群和猪牙花属的Erythronium sibiricum构成另一大支。因此,我们认为Amana群应从广义郁金香属中独立出来,恢复其老鸦瓣属Amana Honda作为属的分类地位。  相似文献   

2.
基于形态性状的淫羊藿属(小檗科)的分支分析   总被引:1,自引:0,他引:1  
小檗科(Berberidaceae)淫羊藿属(Epimedium Linn.)植物全世界约有55种,中国分布有44种,其余种类则分布于东亚、克什米尔、北非和高加索等地。该属植物具有复杂的形态学变异(例如:单叶、一回三出复叶、二回三出复叶,花茎具两叶、三叶或一叶,花瓣无距、有距、距多样式等),导致仅依靠直观判断不能对该属系统进行划分。李超等[1]采用数量分类法对该属55种植物的分类结果多数与Stearn[2]25-26和王悦云等[3]的研究结果一致,但部分种类的分类仍存异议,例如:Sect.  相似文献   

3.
The leaf, stem, root, tuber and dropper anatomy of the orchid tribe Diseae (including the subtribes Satyriinae, Disinae, Brownlecinac, Huttonaeinae and Coryciinae) is reviewed. The study is largely based on investigations of 123 species, and data from several previous publications have also been incorporated. Two characters were identified as being taxonomically valuable: (1) the presence of sclerenchyma caps associated with leaf vascular bundles, and (2) the degree of dissection of the siphonostele of the tuber (‘polystelic’ or ‘monostelic’). The phylogenetic analysis shows that anatomical characters do not change the basic structure of a cladogram that is based on morphological characters. The taxa of Diseae are discussed on the basis of anatomical data. Subtribes Satyriinae (excluding the anatomically unusual genus Pachites), Brownleeinae, Huttonaeinae, and Coryciinae are uniform in. critical anatomical characters. However, subtribe Disinae is rather diverse in vegetative anatomy. Disa sect. Micranthae differs from the rest of the genus in its leaf anatomy. The occurrence of foliar sclerenchyma bundle caps and ‘polystelic’ tubers supports the incorporation of Herschelianthe in Disa sect. Stenocarpa.  相似文献   

4.
The leaf, stem, root, tuber and dropper anatomy of the orchid tribe Diseae (including the subtribes Satyriinae, Disinae, Brownlecinac, Huttonaeinae and Coryciinae) is reviewed. The study is largely based on investigations of 123 species, and data from several previous publications have also been incorporated. Two characters were identified as being taxonomically valuable: (1) the presence of sclerenchyma caps associated with leaf vascular bundles, and (2) the degree of dissection of the siphonostele of the tuber ('polystelic' or 'monostelic'). The phylogenetic analysis shows that anatomical characters do not change the basic structure of a cladogram that is based on morphological characters. The taxa of Diseae are discussed on the basis of anatomical data. Subtribes Satyriinae (excluding the anatomically unusual genus Pachites), Brownleeinae, Huttonaeinae, and Coryciinae are uniform in. critical anatomical characters. However, subtribe Disinae is rather diverse in vegetative anatomy. Disa sect. Micranthae differs from the rest of the genus in its leaf anatomy. The occurrence of foliar sclerenchyma bundle caps and 'polystelic' tubers supports the incorporation of Herschelianthe in Disa sect. Stenocarpa.  相似文献   

5.
原尾纲重新分群的特征分析(六足总纲)   总被引:4,自引:4,他引:4  
1996年第20届国际昆虫学大会(意大利佛罗伦萨)上,尹文英根据多年研究的新发现提出了原尾纲Protura分为3目10科的新建议,仅刊登在该次会议的论文摘要中,至今尚未能详细阐述重新分群的重要特征和分析。本文拟就原尾纲不同类群的成虫和幼虫主要特征进行分析和比较,结果证明原尾纲分为3目(Yuan目、华Yuan目和古Yuan目)10科,更符合原尾虫客观发展的自然规律。  相似文献   

6.
裸藻类植物的分支系统学研究   总被引:1,自引:0,他引:1  
本文选取了裸藻类的33个属级分类单位,以及它们的35个性状,利用分支系统学的原理和方法,对性状的演化极性进行了分析,同时对性状间的极性关系进行了和谐性分析,使性状间极性关系处在较为合理的状态,然后建立了分支分析的数据矩阵。应用徐克学建立的“演化极端结合法”进行微机运算.得简约系数远小于1(o.2159)的分支谱系图。根据分支诺系图对裸藻类的系统发育关系进行了探讨,井与已有的关于裸藻类分类系统和演化假设进行了比较。在此基础上按照裸藻类的亲缘关系及单系原则,对裸藻类的分类等级进行了划分,初步提出了建立1门1纲5目的分类系统。按照在分支谱系中的演化地位,认为裸藻属的5个亚属,明显地都应是独立的属。同时对裸藻类的共生起源与演化的关系也进行了讨论。  相似文献   

7.
    
Hexabathynella is the only cosmopolitan genus of the order Bathynellacea (Crustacea). The known species number 18, found in Europe (9), Africa (1), South America (2), North America (3) and Australia and New Zealand (3). Phylogenetic analysis suggests that the least derived species are those from South America and the most derived those from the Iberian Peninsula, North America and Australia. The five species with the most plesiomorphic characters occur in salt or brackish water, which supports a marine origin for the genus. Phylogenetic and biogeographical analyses suggest that the distribution of the genus can be explained by dispersion and a double vicariant biogeographical model based on plate tectonics and the evolution of the Tethys during the Mesozoic and Cenozoic.  © 2003 The Linnean Society of London . Biological Journal of the Linnean Society , 2003, 78 , 457–466.  相似文献   

8.
西藏野生油菜性状演化与分支分类研究   总被引:1,自引:0,他引:1  
以西藏野生白菜型油菜(Brassica campestris L.)和野生芥菜型油菜(B.juncea Czern.et Coss.)的39个形态学性状为依据,以醉蝶花(Cleome spinosa Jacq.)为外类群,确定了性状的祖征和衍征。应用最大同步法,对35个西藏野生油菜种源的性状演化与分支分类进行了研究。结果表明,野生白菜型油菜和野生芥菜型油菜的基生叶、薹茎叶和花器官性状既有同期演化性状也有非同期演化性状;而伸长茎叶的所有性状均为非同期演化性状,有各自独特的演化规则。西藏野生白菜型油菜分为藏东野生白菜型油菜和藏中野生白菜型油菜2个组,野生芥菜型油菜分为藏中西野生芥菜型油菜和藏南野生芥菜型油菜2个组,各自沿不同的路线演化。  相似文献   

9.
    
The ultrastructure of the oral apparatus is supposed to be significant for elucidating more recent common ancestry and might thus provide support for particular groupings of oligotrichean ciliates. The transmission electron microscopical study on mainly cryofixed Schmidingerella meunieri specimens provides the first detailed data for tintinnids and Oligotrichea in general. Ten new characters are included into the cladistic analysis. These features together with the very limited body of literature suggest that substantial changes in the oral ultrastructure correlate only with the formation of a circular adoral zone in choreotrichids. Despite homoplasious morphological and ontogenetic adaptations to the planktonic lifestyle in halteriid hypotrichs and oligotrichids, their oral apparatuses generally retain the plesiomorphic ultrastructure of the Perilemmaphora. The highly complex ultrastructure of the adoral zone is thus able to accomplish an extension in the zone's functionality without obvious changes; only the position of the adoral zone at the apical cell portion together with a globular to obconical cell shape are apparently crucial. Merely, minute apomorphies characterise the Oligotrichea and tintinnids, respectively. Tintinnids with derived somatic ciliary patterns possess distinct microtubular bundles connecting the oral apparatus with the myoneme in the peduncle.  相似文献   

10.
采用Hennig 86程序,以柄菌蚊科和喙菌蚊科代表种为外群,选取48个特征,使用mhen-nig^*和bb^*指令在586微机上运算,首次对菌蚊科中5亚科28属的28种进行支序分析,探讨各分类单元系统发育关系。结果表明:菌蚊亚科与滑菌蚊亚科的亲缘关系较近,二者互为姐妹群,粘菌蚊亚科属于原始类群;菌蚊亚科为5个亚科中的进化类群;邻菌蚊亚科可能为并系群;真菌蚊亚科是介于邻菌蚊亚科与菌蚊亚科之间的类群。  相似文献   

11.
Andira comprises 29 species distributed throughout tropical America, with two subspecies in Africa. Its fruits are unusual for a papilionoid legume because they are drupes. The majority of species have fruits dispersed by bats, but eight species have larger fruits dispersed by-rodents. Some fruits of both dispersal types are secondarily dispersed by water. Cladistic analysis of chloroplast DNA (cpDNA) restriction site characters discovered four well-supported clades of Andira species. None of these 'cryptic' clades had been recognized by previous workers, because they are not apparently marked by any known morphological innovations. This prompted a search for new characters that might support these groupings. An anatomical study of fruit walls of 25 Andira species revealed the presence of three principal endocarp types, dominated by (1) parenchyma, (2) fibres, or (3) stone cells. These features arc best coded as a single unordered multistate character. When incorporated into a simultaneous cladistic analysis of previously gathered molecular and morphological data, states of this endocarp character are shown to be apomorphies for two of the well-supported clades evident in the cpDNA restriction site data. The most likely plesiomorphic state for the endocarp is parenchyma-dominated. Thicker, stronger endocarps of fibres and stone cells may have evolved in response to the need to protect the seed from predators.  相似文献   

12.
The stapeliads (Apocynaceae — Asclepiadoideae — Ceropegieae) form a group of highly succulent, practically leafless plants with a very diverse floral morphology. They are found in the drier parts of the Old World from southern Africa eastwards to Burma. 55 characters are selected on which a cladistic analysis is based and these are discussed in detail where necessary. From this a phylogeny is produced for the stapeliads. It is shown that they are monophyletic and that they are nested within a larger group among the tribe Ceropegieae of the subfamily Asclepiadoideae. Several of the important innovations that have led to the diversification of the stapeliads in semidesertic regions are discussed. The stapeliads appear to be mainly fly-pollinated. The methods of attraction of flies are mentioned and it is suggested that there are four basic floral types among the stapeliads.  相似文献   

13.
    
A morphological (non-molecular) cladistic analysis of the Velloziaceae is presented. The terminal taxa are 47 species of Velloziaceae plus four taxa as outgroups: Acanthochlamys bracteata (Acanthochlamydaceae), Encholirium scrutor (Bromeliaceae), Thoracocarpus bissectus (Cyclanthaceae) and Pandanus racemosus (Pandanaceae). The species of Velloziaceae sampled represent a significant proportion of the morphological diversity of the family, including all recognized genera and sections. The analysis revealed two major groups within Velloziaceae, supported mainly by stomata, vascular bundles in the pedicel, aquiferous tissues, filaments, anthers, pollen, stigma, seeds, ploidy and chemical characters. Comparison between this and the previous phylogenetic hypotheses for Velloziaceae, together with the two conflicting current classifications, suggests that there is incompatibility concerning the support of current genera and sections. The only three groups supported in all phylogenies are Barbacenioideae sensu Menezes (= Barbacenia sensu Smith & Ayensu), Xerophyta sect. Barbacenioides and Xerophyta sect. Xerophyta sensu Smith & Ayensu.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 157–173.  相似文献   

14.
运用分支分类学方法对天南星属进行了系统发育分析,以天南星属13个组为13个分支分类单位,选择菖蒲属作为外类群,从天南星属植物特征中选取13个性状作为建立数据矩阵的基本资料,并以外类群比较和通行的形态演化规律为依据这些性状进行极化,采用改进后的最大同步法和最小平行进化法进行分类运算,按照最简约的原则,选出演化长度较短的最大同步法谱分支图,作为本文讨论的基础,并在此基础上,探讨了天南星属各组的系统关系。  相似文献   

15.
    
A relatively well–preserved specimen of Cetiosaurus oxoniensis, from the Middle Jurassic (Bajocian) of Rutland, United Kingdom, is described in detail. The material includes a nearly complete cervical series, representative dorsal vertebrae, a fragment of sacrum, anterior caudals, the right femur, and numerous rib and limb fragments. Contrary to previous suggestions that this specimen possesses 14 cervical and ten dorsal vertebrae, it seems more probable that there were at most 13 cervicals and at least 12 dorsals. The vertebral column displays several autapomorphic features which supplement the generic diagnosis of Cetiosaurus, including: (1) a stout, anteriorly directed process located at the top of the neural spine of the twelfth (?) cervical vertebra; and (2) the presence of lateral pits, separated by a thin midline septum, below the transverse processes of middle dorsal vertebrae. Cladistic analysis indicates that Cetiosaurus is probably the sister–taxon to the advanced neosauropod clade. This relationship affects the distribution of particular character states that have played an important role in determining sauropod phylogeny.  相似文献   

16.
    
The phylogenetic relationships of the genera in the geometrid tribe Scopulini (Lepidoptera: Sterrhinae) were examined using 141 characters of adult morphology and ecology. The study material included 92 species, representing all previously recognized genera and covering the morphological variation and full geographical range of the tribe. The cladistic analysis resulted in 20 equally parsimonious trees and a strict consensus cladogram based on these was well resolved. A majority of the recovered synapomorphic characters have been used previously in the taxonomy of the tribe. However, many novel characters were found in the sclerotized structures of the thorax. Many previously recognized genera were found to be nonmonophyletic and based on the present revised, synapomorphy-based classification, the number of recovered genera is reduced considerably. Twenty new generic synonyms and 90 new or revived species combinations are proposed. Seven genera are considered valid, with the large genus Scopula Schrank including over 85% of all species in the tribe. The taxonomic history of the tribe is reviewed and the problems of earlier classifications are discussed. A key to the genera is presented, although an informal diagnosis is preferred. All recognized genera are illustrated and a revised world checklist of the Scopulini is presented.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 473−530.  相似文献   

17.
    
Scanning and electron microscopic studies of the pollen grains of several species of the sub-Saharan African and Madagascan genus Aristea of c . 50 species, supplement data from an earlier study and enable us to include these species in a phylogenetic analysis. TEM examination of a range of pollen grains of representative pollen types in Aristea makes it possible to reinterpret past SEM results so that apertures covered with exine masses and previously called sulculate, are now seen to be either zonasulculate or dizonasulculate. Revised and expanded data are combined in a matrix together with new data for seed morphology in the genus, which like the capsules is remarkably diverse, including angular seeds with reticulate sculpturing, lamellate or triangular-columnar seeds with smooth or reticulate surfaces and with smooth or papillate or areolate margins. This new phylogenetic analysis suggests that Aristea should remain treated as comprising three subgenera. In subgenus Eucapsulares we add a new section Latifolieae for A. latifolia , which seems an isolated relic restricted to the mountains of the Cape Region of South Africa, an area of winter rainfall. Species with similar unspecialized capsule and seed morphology occur only in eastern south and tropical Africa and Madagascar, but they have derived pollen morphology whereas the pollen of A. latifolia is plesiomorphic. This species appears to be the closest living ancestor of the genus. In subgenus Aristea we continue to recognize three sections, sect. Racemosae , sect. Singulares and sect. Aristea. Nesting of subgenus Pseudaristea within section Racemosae of subgenus Aristea is probably an artefact of the analysis and does not receive bootstrap support, and hence we continue to recognize this group of species at subgeneric rank.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 41–68.  相似文献   

18.
李爱花  王仲朗  管开云   《广西植物》2006,26(3):223-226
运用分支分类分析方法对斑龙芋属及其近缘属进行系统发育分析,以4个属的15个种作为15个分支分类单位,选择菖蒲科的菖蒲作为外类群,从斑龙芋属植物特征中选取了14个性状作为建立数据矩阵的基本资料,并以外类群比较和通行的形态演化规律,及核型演化规律为依据对这些性状进行极化,采用改进的最大同步法和最小平行法进行分类运算,按照最简约的原则,运用演化长度较短的最大同步法谱系分支图,作为讨论的基础,讨论了斑龙芋属及其近缘属的系统关系。  相似文献   

19.
ABSTRACT. Several domains of large subunit rRNA from nine trichomonad species have been sequenced. Molecular phylogenies obtained with parsimony and distance methods demonstrate the trichomonads are a monophyletic group which branches very early in the eukaryotic tree. the topology of the trees is in general agreement with traditional views on evolutionary and systematic relationships of trichomonads. A clear dichotomy is noted between the subfamily Trichomonadinae and the subfamily Tritrichomonadinae. In the latter subfamily, a second division separates the " Tritrichomonas muris -type" species from the " Tritrichomonas augusta -type" ones. Previous evolutionary schemes in which the Monocercomonadidae were regarded as the most "primitive" and the Trichomonadidae as more "evolved" are not in agreement with our molecular data. the emergence of Monocercomonas and Hypotrichomonas at the base of the Tritrichomonas lineage suggests a secondary loss of some cytoskeletal structures, the costa and undulating membrane in these genera. This is corroborated by the early branching position of Trichomitus. which possesses a costa and an undulating membrane and has usually been placed among the Trichomonadidae on the basis of cytological characters. A cladistic analysis was applied to the available morphological characters in order to produce a hierarchical grouping of the taxa reflecting their morphological diversity. Supplementary key words. Evolution, molecular phylogeny, morphological cladistic analysis.  相似文献   

20.
瘿绵蚜科系统发育研究(同翅目:蚜总科)   总被引:1,自引:0,他引:1  
张广学  陈小琳 《昆虫学报》1999,42(2):176-183
采用支序分析的方法对瘿绵蚜科的系统发育进行了探讨。研究结果表明,传统的倍蚜族Schlechtendalini、五节根蚜族Fordini和瘿绵蚜族Pemphigini 是单系群,传统的 卷叶绵蚜族Prociphilini 和四脉绵蚜族Tetraneurini是并系群。在瘿绵蚜科的三个亚科中,瘿绵蚜亚科与五节根蚜亚科亲缘关系比与绵蚜亚科更近。另外,根据支序分析结果,建议将丽绵蚜属Formosaphis从瘿绵蚜亚科移入五节根蚜亚科中。  相似文献   

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