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Peter F. M. Coesel - One of the best experts on this subject based on the ideXlab platform.
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Taxonomic notes on desmids from the Netherlands II, with a description of six new species
Phytotaxa, 2018Co-Authors: Marien Van Westen, Peter F. M. CoeselAbstract:From the Netherlands, six desmid species are described as new to science: Closterium joostenii, Cosmarium abbreviatiforme, Cosmarium kouwetsii, Cosmarium spierense, Staurastrum exlooënse, and Staurastrum subcomptum. Furthermore, Closterium archerianum var. pseudocynthia is raised to species level with the name Closterium cynthiaforme. The affinity with similarly looking taxa is discussed.
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Taxonomic notes on desmids from the Netherlands II, with a description of six new species
Phytotaxa, 2018Co-Authors: Marien Van Westen, Peter F. M. CoeselAbstract:From the Netherlands, six desmid species are described as new to science: Closterium joostenii , Cosmarium abbreviatiforme, Cosmarium kouwetsii , Cosmarium spierense , Staurastrum exlooense, and Staurastrum subcomptum . Furthermore, Closterium archerianum var. pseudocynthia is raised to species level with the name Closterium cynthiaforme . The affinity with similarly looking taxa is discussed.
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New or otherwise interesting desmid taxa from the Bangweulu region (Zambia). 2. Genera Staurodesmus, Staurastrum and Xanthidium (Desmidiales)
Plant Ecology and Evolution, 2016Co-Authors: Peter F. M. Coesel, A. Van GeestAbstract:Background and aims – In a second contribution to the desmid flora of the Bangweulu wetlands in Zambia a selection of species from the genera Xanthidium, Staurodesmus and Staurastrum is discussed for their taxonomy and geographical distribution. Material and methods – Samples were collected from Lake Bangweulu and adjacent swamps as well as from Lake WakaWaka. Collection was by squeezing submerged plant material or using a plankton net. Key results – Four taxa are described as new to science: Staurodesmus bangweuluensis, Std. coutei, Std. thomassonii and Staurastrum onychophorum. Three taxa are recombined: Staurastrum zahlbruckneri var. africanum to S. bidentulum var. africanum, Staurastrum unicorne to Staurodesmus unicornis and Arthrodesmus curvatus to Staurodesmus curvatus. Xanthidium decoratum var. longispinum is raised to species level whereas two taxa, Staurodesmus subunguiferus var. longiradiatus and Std. longiradiatus var. granulatus were provided with new names: Staurastrum zambiense and S. zambiense var. granulatum, respectively. Conclusions – Almost all taxa discussed may be considered African endemics underlining the specific character of the African desmid flora. Many identifications in older desmid literature from Africa, especially infraspecific taxa assigned to species originally described from Europe, appear to need a critical revision.
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Taxonomic notes on Dutch desmids VI (Streptophyta, Desmidiales): new species, newly described zygospores
Phytotaxa, 2014Co-Authors: Marien Van Westen, Peter F. M. CoeselAbstract:From the Netherlands, three desmid species are newly described to science: Actinotaenium spinosporum (with zygospores), Staurastrum brachiatoides (with zygospores) and Staurastrum quadriradiatum . In addition to that, zygospores of the rather rare species Staurastrum echinatum are described for the first time. Differences with similar-looking species are discussed.
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Key to the species of Staurodesmus
European Flora of the Desmid Genera Staurastrum and Staurodesmus, 2013Co-Authors: Peter F. M. Coesel, Koos MeestersAbstract:This chapter presents an identification key to the species of Staurastrum. It presents descriptions referring to cells in frontal view and to cell dimensions inclusive of arm-like processes and ornamentation in species of Staurastrum. The chapter discusses morphological characteristics, ecology and geographical distribution of the species of Staurastrum, which include: Staurastrum acarides, Staurastrum aculeatum, Staurastrum acutum and Staurastrum alandicum. The species of Staurastrum also include Staurastrum alpinum, Staurastrum alternans, Staurastrum anatinum and Staurastrum vestitum. Species judged to be either highly questionable or to be identical to others are noted in a list at the end. Taxa described as varieties and formae of those questionable species are not dealt with at all, nor is any attempt made to classify all varieties and formae that are considered not to belong to the species under the name of which they were originally described.Keywords: arm-like processes; ecology; species of Staurastrum; taxa
Okmin Lee - One of the best experts on this subject based on the ideXlab platform.
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molecular phylogeny of the genera Staurastrum and staurodesmus zygnematophyceae streptophyta based on nuclear 18s rdna and chloroplast gene atpb sequences
Algae, 2007Co-Authors: Byeongryeol Moon, Okmin LeeAbstract:To gain insights into the phylogenetic relationships of genus Staurastrum and Staurodesmus, we analyzed nuclearencoded small subunit rDNA of 82 strains, and chloroplast atpB gene sequences of 44 strains belonging to three genera (Staurastrum, Staurodesmus, Cosmarium). Excluding the Staurastrum muticum and S. orbiculare, forty five strains of genus Staurastrum formed a well supported clade. It was shown that with no cell wall sculpture and processes, these two species have a strong phylogenetic relationship with genus Staurodesmus. Therefore, it is strongly recommended to transfer Staurastrum without processes and cell wall sculpture into Staurodesmus. S. obsoletus is a taxa that is transferred from Cosmarium. But, from this study, it has shown a phylogenetic relationship with Cosmarium. Therefore, this species is strongly recommended to transfer back to Cosmarium instead of Staurodesmus. As it was studied before, genus Staurastrum has shown monophyletic. Since the genus taurodesmus groups with Cosmarium, they were shown to be polyphyletic.
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phylogenetic study of genera Staurastrum and staurodesmus zygnemophyceae streptophyta inferred from atpb sequences
Algae, 2005Co-Authors: Byeongryeol Moo, Ansuk Lim, Jaehyun Ahn, Junghoon Park, Okmin LeeAbstract:We analyzed chloroplast ATP synthetase beta subunit(atpB) sequences from 32 strains of the zygnemophycean green algae, Staurastrum, Staurodesmus, and a single species of Xanthidium. A total of 42 atpB sequences including previously published ones was aligned for phylogenetic analyses. The phylogenies were validated with bootstrap analysis and Kishino-Hasegawa test. Taxa of Staurastrum excluding S. muticum indicate that they can be characterized by taxa having the ornamented cell wall or the process of cells. However, the genus Staurodesmus was grouped with taxa having the smooth cell wall and the absence of process or arms. The results suggest that the genus Staurodesmus could be extended to include Staurastrum muticum, Desmidium, Onychonema and Xanthidium. Further taxon sampling of Staurodesmus and putative relatives is necessary for a solid classification of the genus.
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a phylogenetic study of Staurastrum complex chlorophyta inferred from coxiii sequence analysis
Algae, 2004Co-Authors: Byeongryeol Moon, Okmin LeeAbstract:The intergeneric relationship of Staurastrum complex including genus Arthrodesmus and Xanthidium was studied on the basis of mitochondrial coxⅢ sequence variation. Teiling`s suggestion that Staurodesmus was an independent genus apart from genus Staurastrum, Arthrodesmus and Cosmarium was also reevaluated. The phylogeny inferred from coxⅢ gene was not consistent with morphological characteristics of Staurastrum complex. Genus Staurastrum was closely related to genus Xanthidium in the phylogenetic analysis of coxⅢ, but distant to genus Staurodesmus. The taxonomic treatment of genus Staurodesmus as an independent entity could not be determined, because Staurodesmus did not firm a monophyletic Glade. Therefore, genus Staurodesmus could not be treated as an independent genus as Prescott et al. (1982) claimed.
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a phylogenetic significance of several species from genus cosmarium chlorophyta of korea based on mitochondrial coxiii gene sequences
Algae, 2003Co-Authors: Byeongryeol Mun, Okmin LeeAbstract:It has been considered that genus Cosmarium including Staurastrum had the problems in grouping by morphological characters. Sequence data for the Cytochrome Oxidase subunit III (coxIII) were employed to compare with taxa of two divisions of this genus, with sections in each, for evaluating the taxonomic stability of these morphological characters. The division and section systems were not coincided with the phylogeny inferred from coxIII sequences, as the previous reports from us using nuclear rDNA ITS and chloroplast rbcL sequence comparisons in this genus. Two taxa of Staurastrum were not placed within a same clade each other, and one taxon of these was grouped in Arthrodesmus clade. Two genera, Cosmarium and Staurastrum, cannot be regarded as monophyletic from this result. Mitochondrial coxIII gene was considered as a useful phylogenetic tool to evaluate evolutionary relationships of desmids as in the case of land plants.耀Ѐက
A. F. Luknitskaya - One of the best experts on this subject based on the ideXlab platform.
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Conjugates (Charophyta, Conjugatophyceae) of the National Park «Valdaiskiy» (Novgorod Region, Russia)
Novosti sistematiki nizshikh rastenii, 2017Co-Authors: A. F. LuknitskayaAbstract:Data on the flora of freshwater algae of the Conjugatophyceae of the National Park (NP) «Valdaiskiy» (Novgorod Region, Russia) represent the first generalization on the flora of the conjugates of the Novgorod Region. In total 152 species, 8 varieties and 1 form of 27 genera (Actinotaenium, Bambusina, Closterium, Cosmarium, Сylindrocystis, Desmidium, Docidium, Euastrum, Gonatozygon, Haplotaenium, Hyalotheca, Micrasterias, Mougeotia, Netrium, Penium, Planotaenium, Pleurotaenium, Raphidiastrum, Spirogyra, Spirotaenia, Spondylosium, Sphaerozosma, Staurastrum, Staurodesmus, Tetmemorus, Xanthidium, Zygnema) are listed. The NP area Region. Data on occurrence of 124 species and intraspecific conjugate taxa in Demyanskiy and Okulovskiy districts are presented for the first time. The list of the taxa is annotated by data on their distribution in collecting sites in these districts of the NP, and abundance in the samples. Data on the conjugates of Valdayskiy District were published earlier, and the list is provided with appropriate bibliographic references. Data on the conjugates of other districts of the Novgorod Region is scarcely available at present. The following genera are represented by the greatest number of species: Cosmarium (46 species and 2 varieties), Staurastrum (27 species and 3 varieties) and Closterium (17 species and 1 variety). Micrasterias americana, Sphaerozosma laeve and Actinotaenium tessellatum are rare worldwide. Staurastrum chaetoceros is recorded for the first time in the Novgorod Region.
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To the flora of сonjugates (Streptophyta, Conjugatophyceae) of the Valdai District area of the National Park «Valdaiskiy» (Novgorod Region, Russia)
Novosti sistematiki nizshikh rastenii, 2014Co-Authors: A. F. LuknitskayaAbstract:76 species, 3 varieties and 1 form from 21 genera of Streptophyta, Conjugatophyceae (Actinotaenium, Bambusina, Closterium, Cosmarium, Cylindrocystis, Euastrum, Gonatozygon, Haplotaenium, Micrasterias, Mougeotia, Netrium, Penium, Planotaenium, Pleurotaenium, Raphidiastrum, Spirogyra, Spirotaenia, Staurastrum, Staurodesmus, Tetmemorus, Xanthidium) were found in the basins of the Valdai District area of the National Park «Valdaiskiy» (Novgorod Region, Russia). The list of species is annotated with data on the species distribution in 55 collecting sites of 29 water bodies of the national park, and species abundance in collected samples according to Luknitskaya (2009). Among above mentioned genera, the genus Cosmarium is represented by the greatest number of species (20). Staurastrum chaetoceros has been found for the first time for the Novgorod Region.
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To the flora of Zygnematophyceae (Streptophyta) of Valdaiskoe Lake (Novgorod Region, Russia)
Novosti sistematiki nizshikh rastenii, 2013Co-Authors: A. F. LuknitskayaAbstract:49 species and 2 varietas from 11 genera of Streptophyta, Zygnematophyceae (Closterium, Cosmarium, Cosmoastrum, Euastrum, Micrasterias, Mougeotia, Pleurotaenium, Raphidiastrum, Spirogyra, Staurastrum, Staurodesmus) were found in Valdaiskoe Lake (National Park «Valdaisky», Novgorod Region, Russia). Leading genus is Cosmarium (23 species).
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The additional data for the flora of conjugates (Streptophyta, Zygnematophyceae) of Mshinskaya Wetland System (Leningrad Region)
Novosti sistematiki nizshikh rastenii, 2012Co-Authors: A. F. LuknitskayaAbstract:51 species from 18 genera of Streptophyta, Zygnematophyceae (Actinotaenium, Bambusina, Closterium, Cylindrocystis, Cosmarium, Cosmoastrum, Docidium, Euastrum, Micrasterias, Mougeotia, Netrium, Pleurotaenium, Raphidiastrum, Spirogyra, Staurastrum, Staurodesmus, Tetmemorus, Xanthidium) were found in Mshinskaya Wetland System (Leningrad Region, Russia). Leading genera are Cosmarium (10 species), Closterium (10), Staurastrum (8 species).
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Preliminary data to the flora of conjugates (Streptophyta, Zygnematophyceae) of Mshinskoye Bog System (Leningrad Region)
Novosti sistematiki nizshikh rastenii, 2011Co-Authors: A. F. LuknitskayaAbstract:73 species and varieties from 15 genera of Streptophyta, Zygnematophyceae (Actinotaenium, Closterium, Cylindrocystis, Cosmarium, Cosmoastrum, Desmidium, Euastrum, Gonatozygon, Mougeotia, Netrium, Pleurotaenium, Spirogyra, Spondylosium, Staurastrum, Staurodesmus) were found in Mshinskoye Bog System (Leningrad Region, Russia). Cosmarium (17 species), Closterium (16), Euastrum (8 species) are leading genera.
Claude Lemieux - One of the best experts on this subject based on the ideXlab platform.
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the complete chloroplast dna sequences of the charophycean green algae Staurastrum and zygnema reveal that the chloroplast genome underwent extensive changes during the evolution of the zygnematales
BMC Biology, 2005Co-Authors: Monique Turmel, Christian Otis, Claude LemieuxAbstract:The Streptophyta comprise all land plants and six monophyletic groups of charophycean green algae. Phylogenetic analyses of four genes from three cellular compartments support the following branching order for these algal lineages: Mesostigmatales, Chlorokybales, Klebsormidiales, Zygnematales, Coleochaetales and Charales, with the last lineage being sister to land plants. Comparative analyses of the Mesostigma viride (Mesostigmatales) and land plant chloroplast genome sequences revealed that this genome experienced many gene losses, intron insertions and gene rearrangements during the evolution of charophyceans. On the other hand, the chloroplast genome of Chaetosphaeridium globosum (Coleochaetales) is highly similar to its land plant counterparts in terms of gene content, intron composition and gene order, indicating that most of the features characteristic of land plant chloroplast DNA (cpDNA) were acquired from charophycean green algae. To gain further insight into when the highly conservative pattern displayed by land plant cpDNAs originated in the Streptophyta, we have determined the cpDNA sequences of the distantly related zygnematalean algae Staurastrum punctulatum and Zygnema circumcarinatum. The 157,089 bp Staurastrum and 165,372 bp Zygnema cpDNAs encode 121 and 125 genes, respectively. Although both cpDNAs lack an rRNA-encoding inverted repeat (IR), they are substantially larger than Chaetosphaeridium and land plant cpDNAs. This increased size is explained by the expansion of intergenic spacers and introns. The Staurastrum and Zygnema genomes differ extensively from one another and from their streptophyte counterparts at the level of gene order, with the Staurastrum genome more closely resembling its land plant counterparts than does Zygnema cpDNA. Many intergenic regions in Zygnema cpDNA harbor tandem repeats. The introns in both Staurastrum (8 introns) and Zygnema (13 introns) cpDNAs represent subsets of those found in land plant cpDNAs. They represent 16 distinct insertion sites, only five of which are shared by the two zygnematalean genomes. Three of these insertions sites have not been identified in Chaetosphaeridium cpDNA. The chloroplast genome experienced substantial changes in overall structure, gene order, and intron content during the evolution of the Zygnematales. Most of the features considered earlier as typical of land plant cpDNAs probably originated before the emergence of the Zygnematales and Coleochaetales.
Michael Melkonian - One of the best experts on this subject based on the ideXlab platform.
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molecular phylogeny of Staurastrum meyen ex ralfs and related genera zygnematophyceae streptophyta based on coding and noncoding rdna sequence comparisons1
Journal of Phycology, 2005Co-Authors: Andrey A Gontcharov, Michael MelkonianAbstract:Nuclear-encoded small subunit rDNA, 1506 group I intron, and internal transcribed spacer sequences were obtained from 39 strains representing five core desmid genera, Staurastrum, Staurodesmus Teil., Cosmarium Corda ex Ralfs, Xanthidium Ehr. ex Ralfs, and Euastrum Ehr. ex Ralfs (Desmidiaceae, Zygnematophyceae), and used individually and concatenated to assess phylogenetic relationships between putatively allied members of the family. To identify positional homology between divergent noncoding sequences, secondary structure models were generated and their reliability assessed by screening the alignment for compensating base changes. The phylogeny based on coding and noncoding sequence comparisons confidently resolved a monophyletic core of the genus Staurastrum but also revealed the artificial nature of the traditional genus. Twenty distinct species representing a wide range of morphotypes of Staurastrum formed a strongly supported generic clade that was further split into three well-resolved lineages. The phylogenetic relationships revealed within Staurastrum were in conflict with all previous formal or informal classifications of the genus. The genera Staurodesmus and Cosmarium were shown to be highly polyphyletic, and some morphologically similar taxa displayed high sequence divergence that exceeded generic boundaries. Apparently, the taxonomic significance of some morphological characters in Staurastrum and other desmid genera has been greatly overestimated.
