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1.
心叶三脉蕨(新属,新组合)及大羽羊齿类的分类位置   总被引:1,自引:0,他引:1  
报道大羽羊齿类中的一真蕨植物新属和新组合。标本采自福建将乐县晚古生代的“龙潭组”。曾以脉序介于重网状和单网状之间,鉴定为心叶单网羊齿(新种)(Gigantonoclea cardio-phylla Zhu etGeng)。重新研究后,根据其三出脉和不完全的重网状脉式,又发现了其孢子囊群,从营养叶看,可归入大羽羊齿类,介于大羽羊齿和单网羊齿之间,从孢子囊群看,则肯定是真蕨,重新命名为心叶三脉蕨(新属、新组合)[Trinerviopteris cardiophylla (Zhu et Geng)Zhu gen.et com b.nov.]。与之同时发现的其它植物有:Sphenophyllum em arginatum 、Bow -m anites laxus、Lobatannularia lingulata、Chansitheca palaeosilvana、Ch. cf. kidstonii、Pecopteris anderssonii、P.echinata、P.? taiyuanensis、P.unita、Danaeites m irabilis、Fascipterisdensata、Cladophlebis ? perm ica、C  相似文献   

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利用蛋白银染色技术对采自青岛沿海砂隙的寡毛类纤毛虫Strombidium kielum进行了形态学重描述,发现该种在寡毛类纤毛虫中具有独一无二的纤毛下器模式,因此为其建立了1新属Varistrombidium,特征为具有5条斜穿虫体的体动基列,其中体动基列1和2延伸到虫体背部,终止于虫体尾端。对Varistrombidium kielum(Maeda&Carey,1985)nov.comb.的小亚基RNA序列分析表明,该种位于Strombidiidae科内,与其形态学相近种Omegastrombidium elegans聚在一起。同时对其小亚基RNA序列可变区2的二级结构进行了预测并与其形态学相似种进行了比较。还对Apostrombidium pseudokielum Xuet al.,2009进行了补充性描述。  相似文献   

4.
The Aegagropila clade represents a unique group of cladophoralean green algae occurring mainly in brackish and freshwater environments. The clade is sister to the species‐rich and primarily marine Cladophora and Siphonocladus lineages. Phylogenetic analyses of partial LSU and SSU nrDNA sequences reveal four main lineages within the Aegagropila clade, and allow a taxonomic reassessment. One lineage consists of two marine ‘Cladophora’ species, for which the new genus Pseudocladophora and the new family Pseudocladophoraceae are proposed. For the other lineages, the family name Pithophoraceae is reinstated. Within the Pithophoraceae, the earliest diverging lineage includes Wittrockiella and Cladophorella calcicola, occurring mainly in brackish and subaerial habitats. The two other lineages are restricted to freshwater. One of them shows a strong tendency for epizoism, and consists of Basicladia species and Arnoldiella conchophila. The other lineage includes Aegagropila, Pithophora and a small number of tropical ‘Cladophora’ species. The latter are transferred to the new genus Aegagropilopsis. Previously, polypyramidal pyrenoids had been suggested to be apomorphous for this clade, but we report the finding of both polypyramidal and bilenticular pyrenoids in members of the Pithophoraceae, and thus show that this character has no diagnostic value.  相似文献   

5.
Systematics of the red algal order Rhodymeniales was investigated using combined large‐subunit nuclear ribosomal DNA (LSU) and elongation factor 2 (EF2) analyses. These data were subjected to distance, parsimony, and Bayesian analyses, and the resulting phylogenies were largely congruent with previously published SSU results in that the four currently recognized rhodymenialean families (Champiaceae, Faucheaceae, Lomentariaceae, and Rhodymeniaceae) were resolved as monophyletic lineages (with the exception of Coelothrix, which is here transferred to the Champiaceae from the Rhodymeniaceae). In addition, taxa presently considered as incertae sedis consisted of two lineages (Fryeella lineage and Hymenocladia lineage). Based on these results, two new families are proposed: (i) the Fryeellaceae fam. nov. to accommodate the genera Fryeella, Hymenocladiopsis, and a new taxon from Tasmania, Australia; and (ii) the Hymenocladiaceae fam. nov., to accommodate Asteromenia, Hymenocladia, and Erythrymenia. In addition to resolving familial relationships, these analyses resolved some novel interspecific affinities, and we propose a new genus, Neogastroclonium gen. nov., for Gastroclonium subarticulatum, a species that differs significantly in both morphology and molecular data from genuine species of Gastroclonium. Relationships among additional faucheacean and lomentariacean taxa were investigated using LSU data only, and these results are discussed. The familial classification of the Rhodymeniales proposed herein is discussed in light of vegetative and reproductive anatomy, most notably the ontogeny of the tetrasporangia.  相似文献   

6.
We examined the molecular phylogeny and ultrastructure of Chlorogonium and related species to establish the natural taxonomy at the generic level. Phylogenetic analyses of 18S rRNA and RUBISCO LSU (rbcL) gene sequences revealed two separate clades of Chlorogonium from which Chlorogonium (Cg.) fusiforme Matv. was robustly separated. One clade comprised Cg. neglectum Pascher and Cg. kasakii Nozaki, whereas the other clade included the type species Cg. euchlorum (Ehrenb.) Ehrenb., Cg. elongatum (P. A. Dang.) Francé, and Cg. capillatum Nozaki, M. Watanabe et Aizawa. On the basis of unique ultrastructural characteristics, we described Gungnir Nakada gen. nov. comprising three species: G. neglectum (Pascher) Nakada comb. nov., G. mantoniae (H. Ettl) Nakada comb. nov., and G. kasakii (Nozaki) Nakada comb. nov. We also emended Chlorogonium as a monophyletic genus composed of Cg. euchlorum, Cg. elongatum, and Cg. capillatum. Because Cg. fusiforme was distinguished from the redefined Chlorogonium and Gungnir by the structure of its starch plate, which is associated with pyrenoids, we reclassified this species as Rusalka fusiformis (Matv.) Nakada gen. et comb. nov.  相似文献   

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报道斑痣盘菌科的两个寄生种,即生于茶树Camelliasinensis(L.)Kuntze枝梢上的硬湿皮盘菌新种HypoheliondurumY.R.Lin,C.L.Hou&S.J.Wangsp.nov.和生于青杄PiceawilsoniiMast.针叶上的线孢小沟盘菌新组合Lirulafiliformis(Darker)Y.R.Lin&S.J.Wangcomb.nov.。湿皮盘菌属HypohelionJohnston同时为中国新记录属。对此二种进行了汉文描述、图解和讨论,新种附有拉丁文特征简介。供研究标本保藏于安徽农业大学森林保护教研室(AAUFP)。  相似文献   

9.
Twelve populations of filamentous, heterocytous scytonematoid cyanobacteria from subaerophytic (mainly epiphytic) habitats in subtropical and tropical Brazil (São Paulo) were studied. The populations form a uniform cluster, which differs from the traditional scytonematoid genera genetically and by several indistinct, but typical morphological characters (fasciculation of filaments, rare false branching). Two strains were isolated in monospecific cultures. Molecular analyses were performed on these strains from natural populations taken from bromeliad leaves and iron water pipes. Because the results from 16S rRNA gene sequencing indicated the separate position of this cyanobacterium at the generic level, a new genus, Brasilonema, is proposed with the type species Brasilonema bromeliae. The new genus is described using combined molecular and cytomorphological criteria, in accordance with the nomenclatorial recommendations of both the Bacteriological Code and the Botanical Code of Nomenclature (cf. Oren 2004 ). The ultrastructure of the type species was studied, and vacuole‐like structures in the cells were explained. The genus Brasilonema is commonly distributed, particularly in subaerophytic habitats from southeastern Brazil. The type species (B. bromeliae) has a rather curious ecology, living epiphytically (in phytothelmes) inside the vase‐shaped leaf rosettes of bromeliads.  相似文献   

10.
Eucheuma acanthocladum (Harvey) J. Agardh, E. gelidium (J Agardh) J. Agardh, E. echinocarpum Areschoug and E. schrammii(P. et H. Crouan) J. Agardh from the tropical and warm temperate waters of the western Atlantic Ocean and Caribbean Sea are transferred to a new genus, Meristiella. Meristiella exhibits the following Unique combination of characters among genera in the Solieriaceae: (1) rotated periaxial cells, (2) a loosely filamentous medulla. (3) an auxiliary cell complex, (4) Single and twin connecting filaments and (5) spinose cystocarps composed of a central, small-celled placentum, based on its reproductive features, Meristiella. is assigned to the tribe Agardhielleae. Culture experiments and herbarium studies provide evidence that E, gelidium and E. acantghocladum are conspecific. Lectotypes are designated for the included species.  相似文献   

11.
Chrysolepidomonas gen. nov. is described for single-celled monads with two flagella, a single chloroplast, and distinctive canistrate and dendritic scales. The type species, Chrysolepidomonas dendrolepidota sp. nov., is described for the first time. The canistrate scales bear eight “bumps” on the top surface, and the dendriticscales have a tapered base with a quatrifid tip. These organic scales are formed in the Golgi apparatus and storred in a scale reservoir. The scale reservoir is bounded on two sides by the R1 and R2 in microtubular roots of the basal apparatus. The cyst (=stomatocyst, statospore) forms endogenously by means of a silica deposition vesicle. The outer cyst surface is smooth, and the pore region is unornamented. Two other organisms bearing canistrate and dendritic scales, previously assigned to the genus Sphaleromants, are transferred to the genus Chrysolepidomonas. They are C.angalica sp. nov. and C. marine(Pienaar) comb. nov. The distinguishing features of Chrysolepidomonas and Sphaleromantis are discussed. A new family, Chrysolepidomonadceae fam. noc., is described for flagellates covered with organic scales.  相似文献   

12.
Pfiesteria shumwayae Glasgow et Burkholder is assigned to a new genus Pseudopfiesteria gen. nov. Plate tabulation differences between Pfiesteria and Pseudopfiesteria gen. nov. as well as a maximum likelihood phylogenetic analysis based on rDNA sequence data warrant creation of this new genus. The Kofoidian thecal plate formula for the new genus is Po, cp, X, 4′, 1a, 6′′, 6c, PC, 5+s, 5′′′, 0p, 2′′′′. In addition to having six precingular plates, P. shumwayae comb. nov. also has a distinctive diamond or rectangular‐shaped anterior intercalary plate. Both Pfiesteria and Pseudopfiesteria gen. nov. are reassigned to the order Peridiniales based on an apical pore complex (APC) with a canal (X) plate that contacts a symmetrical 1′, four to five sulcal plates, and the conservative hypothecal tabulation of 5′′′, 0p, and 2′′′′. These morphological characters and the life histories of Pfiesteria and Pseudopfiesteria are consistent with placement of both genera in the Peridiniales. Based on the plate tabulations for P. shumwayae, P. piscicida, and the closely related “cryptoperidiniopsoid” and “lucy” groups, the family Pfiesteriaceae is amended to include species with the following tabulation: 4‐5′, 0‐2a, 5‐6′′, 6c, PC, 5+s, 5′′′, 0p, and 2′′′′ as well as an APC containing a pore plate (Po), a closing plate (cp), and an X plate; the tabulation is expanded to increase the number of sulcal plates and to include a new plate, the peduncle cover (PC) plate. Members of the family have typical dinoflagellate life cycles characterized by a biflagellated free‐living motile stage, a varying number of cyst stages, and the absence of multiple amoeboid stages.  相似文献   

13.
The culture CCMP 1383, obtained from sea-ice brine collected in McMurdo Sound (Ross Sea, Antarctica), is a small gymnodinioid dinoflagellate. This species is very abundant in the upper land-fast sea ice, where it can both grow and overwinter as a spiny encysted stage. The motile vegetative stage and the cyst produced in the culture were studied by scanning electron microscopy (SEM) and transmission electron micrscopy (TEM). The amphiesma of the vegetative cells is constituted by thin vesicles that are organized into nine latitudinal series of plates: three in the epitheca, two in the cingulum, and four in the hypotheca. The same tabulation is reflected in the cyst wall by acicular processes arising from the center of paraplates, with the exception of the paracingulum, in which acicular processess are absent. On the basis of the peculiar plate pattern of this dinoflagellate, we establish the new genus Polarella and the new species Polarella glacialis (family Suessiaceae, order Suessiales). This species has a remarkable similarity with fossil Suessiaceae cysts dating back to the Triassic and Jurassic and represents, up to now, the only extant member of the subfamily Suessiaceae. Phylogenetic analysis based on the small-subunit ribosomal RNA gene confirmed the placement of this species in the order Suessiales and its close relationship with the genus Symbiodinium Freudenthal.  相似文献   

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Two cryophilic Desmotetra species, D. aureospora , sp. nov., and D. antarctica (Fritsch) Ling appear to be unique to the southern hemisphere snow ecosystem, or at least to the Windmill Island region, Antarctica. They have not been encountered in previous extensive studies of the Arctic and northern alpine regions. Also unusual are the higher pH (6.8 and 7.8) and conductivities of 279 μS·cm−1 and 426 μS·cm−1 for habitat conditions of D. antarctica that can be attributed to the influence of penguin guano. Both species are characterized by cells enveloped in individual mucilage layers, 1–3 contractile vacuoles, and a cup-shaped chloroplast containing a diffuse pyrenoid. The cells divided in three planes to form cubical loosely aggregated green cell packages embedded in mucilage. Vegetative cells of the two species cannot be distinguished with certainty; however, their zygospores are very different. Desmotetra aureospora has spherical, smooth-walled, golden zygospores, whereas D. antarctica has pale, yellow green, aereolate zygospores. Mucilage stalk morphology of cells in stationary-phase cultures can also be used to separate the two species. Zygospores of D. antarctica have previously been identified as the snow alga Trochiscia antarctica Fritsch. Both species are currently maintained in culture at the Australian Antarctic Division. The cultures did not grow at temperatures above 15° C. The two species are compared with the soil alga D. stigmatica (Deason) Deason et Floyd, the only other species in the genus, and also with Chlorosarcina stigmatica Deason strain T105. Results show that the three Desmotetra species form a natural group and that the absence or presence of a wall on the zoospore is of dubious value in classifications of green algal taxa above the species level.  相似文献   

16.
On the basis of LM, we isolated strains of two species of fusiform green flagellates that could be assigned to former Chlorogonium (Cg.) Ehrenb. One species, “Cg.”heimii Bourr., lacked a pyrenoid in its vegetative cells and required organic compounds for growth. The other was similar to Cg. elongatum (P. A. Dang.) Francé and “Cg.”acus Nayal, but with slightly smaller vegetative cells. Their molecular phylogeny was also studied based on combined 18S rRNA, RUBISCO LSU (rbcL), and P700 chl a‐apoprotein A2 (psaB) gene sequences. Both species were separated from Chlorogonium emend., Gungnir Nakada and Rusalka Nakada, which were formerly assigned to Chlorogonium. They were accordingly assigned to new genera, Tabris Nakada gen. nov. and Hamakko (Hk.) Nakada gen. nov. as T. heimii (Bourr.) Nakada comb. nov. and Hk. caudatus Nakada sp. nov., respectively. Tabris is differentiated from other genera of fusiform green flagellates by its vegetative cells, which only have two apical contractile vacuoles and lack a pyrenoid in the chloroplast. Hamakko, on the other hand, is distinguishable by the fact that its pyrenoids in vegetative cells are penetrated by flattened thylakoid lamellae.  相似文献   

17.
三冠大孢属Tricristatispora是我国西部地区上三叠统特征的常见化石。此前分别命名为Calamospora tricristata Li,1974,Tricristatispora aphela Liu,1981和Viburamegaspora orientalis Zhang,1984的几个种实属具相同特征的同种化石,后2个种名为前1种的晚出同义名,应予废弃。这里将种名tricrist  相似文献   

18.
Synchysidendron, gen. nov., is segregated from Diaphorodendron DiMichele emend. Both genera are determinate, rhizomorphic, arborescent lycopsids that share identical reproductive organs but differ radically in growth architecture and consequently in the timing of reproduction. Cones in Synchysidendron (two species) are borne on late-formed crown branches; in Diaphorodendron (three species) cones are borne on deciduous lateral branches, produced over much of the life of the tree. The two genera also differ in several characteristics of the stele and periderm. We hypothesize that Diaphorodendron gave rise to Synchysidendron within their shared Late Carboniferous coal-swamp habitat, by heterochronic suppression of lateral branching during ontogeny. Together, these genera form a highly apomorphic clade, here recognized as the new family Diaphorodendraceae, that is distinguished primarily by siphonostelic axes, a bifacial periderm, distinctive megasporangia, and gulate megaspores.  相似文献   

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Specimens from the exsiccatae Phycotheca BorealiAmericana number 698 are shown to represent two distinct species. One of them, formerly known as Callithamnion halliae, is transferred to Aglaothamnion on the basis of its uninucleate cells. The specimens exhibit distichous branching and are ecorticate. A lectotype is proposed for one of the P.B.-A. #698 specimens displaying these characters . Aglaothamnion halliae ( Collins) comb. nov. is an earlier name for Aglaothamnion westbrookiae Rueness et L'Hardy-Halos. The second species, together with specimens of P.B.-A. #1896, has radial branching and corticated axes and is described herein as a new species , Aglaothamnion collinsii. The binomial Aglaothamnion boergesenii ( Aponte et Ballantine ) L'Hardy-Halos et Rueness in Aponte, Ballantine, et J. Norris is validated. A key to the tropical and warm-temperate western Atlantic species of Aglaothamnion is presented .  相似文献   

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