Polyfázické přístupy v taxonomii zelených aerofytických řas

Conclusions Traditionaltaxonomyoftendependson single charactersusedfor distin- guishingparticularspecies.ln thisthesis,I haveillustratedapplicationofpoly- phasicapproachesin taxonomyof greenaerophyticalgae.Theseapproachesare basedon thecombinationof variouscharacters(traditionalmorphology,modern molphologicalapproaches,SSU, ITS rDNA andgeneintronsequencing)forthe speciesrecognitionin greenalgae. The morphologicalcharactersaloneareoftennot sufficientfor speciesde- lirnitation,thoughtheycan be usedfor routinespeciesidentificationModern rnorphologicalapproacheslike confocalmicroscopyallow to detectclearmor- phologicaldifferencesarnonginvestigatedcloselyrelatedspecies,evenifat first sightthesemorphologicallyvery uniformalgaehardlydifferatthe morphologi- cal level. A numberof rnorphologicalcharactersdoesnot reflectgeneticrela- tionships.Rathertheyareinfluencedby variousenvironmentalor culturecondi- tions.For example,cell dimensionsin Klebsorntidiuntcanbe distinctivelyinflu- encedby pH, humidity,illLrminationandternperatureconditions.However,with theaid of molecularmarkerswe candetectproperrnorphologicalfeaturesuseful for speciesdifferentiationt. ln .lslerochlorls,correlationtestof geneticdistances and morphologicaldifferencesrevealedusefulnessof particularchloroplast charactersforspeciesdelirnitation....Conclusions Traditionaltaxonomyoftendependson single charactersusedfor distin- guishingparticularspecies.ln thisthesis,I haveillustratedapplicationofpoly- phasicapproachesin taxonomyof greenaerophyticalgae.Theseapproachesare basedon thecombinationof variouscharacters(traditionalmorphology,modern molphologicalapproaches,SSU, ITS rDNA andgeneintronsequencing)forthe speciesrecognitionin greenalgae. The morphologicalcharactersaloneareoftennot sufficientfor speciesde- lirnitation,thoughtheycan be usedfor routinespeciesidentificationModern rnorphologicalapproacheslike confocalmicroscopyallow to detectclearmor- phologicaldifferencesarnonginvestigatedcloselyrelatedspecies,evenifat first sightthesemorphologicallyvery uniformalgaehardlydifferatthe morphologi- cal level. A numberof rnorphologicalcharactersdoesnot reflectgeneticrela- tionships.Rathertheyareinfluencedby variousenvironmentalor culturecondi- tions.For example,cell dimensionsin Klebsorntidiuntcanbe distinctivelyinflu- encedby pH, humidity,illLrminationandternperatureconditions.However,with theaid of molecularmarkerswe candetectproperrnorphologicalfeaturesuseful for speciesdifferentiationt. ln .lslerochlorls,correlationtestof geneticdistances and morphologicaldifferencesrevealedusefulnessof particularchloroplast charactersforspeciesdelirnitation....Department of BotanyKatedra botanikyFaculty of SciencePřírodovědecká fakult

Polyphasic approaches in the taxonomy of green aerophytic algae

Conclusions Traditionaltaxonomyoftendependson single charactersusedfor distin- guishingparticularspecies.ln thisthesis,I haveillustratedapplicationofpoly- phasicapproachesin taxonomyof greenaerophyticalgae.Theseapproachesare basedon thecombinationof variouscharacters(traditionalmorphology,modern molphologicalapproaches,SSU, ITS rDNA andgeneintronsequencing)forthe speciesrecognitionin greenalgae. The morphologicalcharactersaloneareoftennot sufficientfor speciesde- lirnitation,thoughtheycan be usedfor routinespeciesidentificationModern rnorphologicalapproacheslike confocalmicroscopyallow to detectclearmor- phologicaldifferencesarnonginvestigatedcloselyrelatedspecies,evenifat first sightthesemorphologicallyvery uniformalgaehardlydifferatthe morphologi- cal level. A numberof rnorphologicalcharactersdoesnot reflectgeneticrela- tionships.Rathertheyareinfluencedby variousenvironmentalor culturecondi- tions.For example,cell dimensionsin Klebsorntidiuntcanbe distinctivelyinflu- encedby pH, humidity,illLrminationandternperatureconditions.However,with theaid of molecularmarkerswe candetectproperrnorphologicalfeaturesuseful for speciesdifferentiationt. ln .lslerochlorls,correlationtestof geneticdistances and morphologicaldifferencesrevealedusefulnessof particularchloroplast charactersforspeciesdelirnitation...

<i>Rindifilum ramosum</i> gen. nov., sp. nov., un nouveau genre d’eau douce au sein des Ulvales (Ulvophyceae, Chlorophyta)

Le présent article fournit une étude phylogénétique et morphologique de deux souches qui s’avèrent représenter un genre nouveau et une espèce nouvelle, Rindifilum ramosum gen. nov., sp. nov., au sein de la famille des Ctenocladiaceae (Ulvales). Rindifilum ramosum gen. nov., sp. nov. se développe en association avec le genre Verrucaria Schrader, un ascomycète lichénisé. Les reconstructions phylogénétiques basées sur les gènes rbcL, 18S rRNA et tufA ont montré que les souches étudiées appartiennent à une lignée distincte de celles séquencées jusqu’à présent. De plus, les comparaisons basées sur les observations morphologiques n’ont révélé aucune différence entre les deux souches. Le nouveau genre Rindifilum gen. nov. présente une combinaison unique de caractéristiques morphologiques, comme les cellules en forme de « poire » qui se développent directement en un « filament en forme de marteau », ce qui le distingue de toutes les autres algues vertes décrites jusqu’à présent.The present paper provides a phylogenetic and morphological study of two strains that turn out to represent a new genus and species, Rindifilum ramosum gen. nov., sp. nov., within the family Ctenocladiaceae (Ulvales). Rindifilum ramosum gen. nov., sp. nov. grows in association with the lichenized ascomycetes genus Verrucaria Schrader. Phylogenetic reconstructions based on the rbcL, 18S rRNA and tufA genes showed that the investigated strains belonged to a lineage distinct from those sequenced so far. Moreover, comparisons based on morphological observations revealed no differences between the two strains. The newly genus Rindifilum gen. nov. exhibits a unique combination of morphological features, as the “pear-shaped” cells that develop directly into a “hammer-shaped filament”, making it distinct from all other green algae described so far.</p

Diversity of subaerial algae and cyanobacteria growing on bark and wood in the lowland tropical forests of Singapore

Background and aims – Knowledge on diversity and distribution of algae and cyanobacteria in subaerial habitats still lags behind those of freshwater and marine environments. Notably, data on diversity of microalgae in tropical corticolous habitats are still scarce. We investigated species composition of subaerial epixylic algae and cyanobacteria from two Singaporean rainforest localities. We asked whether there are differences in species composition and alpha-diversity of samples taken in different areas and in different habitat types (bark vs. decaying bare wood). In addition, we asked whether there are differences in species turnover (beta-diversity) among different habitat types and areas. Methods – The cultivation-based approach and the microscopic analysis of populations were used. In total, 20 samples of bark and decaying wood from two forested areas were analyzed. Statistical analyses involved the non-metric multidimensional scaling (NMDS) of species data. Significance of differences in algal composition between groups of samples was evaluated by the non-parametric two-way ANOSIM (Analysis of Similarities) using the crossed design with permutations in blocks. The SIMPER method was used to identify species that characteristically discriminate between habitat types and sampling areas. Key results – In total, 57 species were identified. Green algae (Trebouxiophyceae, Chlorophyceae, Trentepohliales) were dominant, and Cyanobacteria were the second most frequent group. The dominants of the subaerial assemblages differed from corresponding temperate habitats and, in addition, their alpha-diversity was considerably higher. Several green algal morphospecies were characteristic for the bark localities (e.g. Dictyochloropsis spp., Pseudomarvania aerophytica, Printzina effusa and Printzina lagenifera). The alpha-diversity was similar in both habitat types, but the species turnover among samples (beta-diversity) was significantly higher in the decaying wood samples. Conclusions – Tropical corticolous habitats probably harbour higher diversity than corresponding temperate habitats. High beta-diversity of decaying wood illustrates general importance of this substrate for biodiversity of subaerial algae in the tropics

Splitting of Micrasterias fimbriata (Desmidiales, Viridiplantae) into two monophyletic species and description of Micrasterias compereana sp. nov.

Background – Micrasterias fimbriata, a conspicuous desmid species, has recently been shown to be composed of two clearly delimited monophyletic clades within the genus Micrasterias, closely related to several other well-defined Micrasterias species ( M. brachyptera, M. rotata, M. torreyi ). The members of both clades can also be unambiguously recognized by careful morphological analysis. In addition, their distribution areas in Europe and North America are largely vicariant. Interestingly, morphological features of one of the clades do not correspond with any of the previously described infraspecific taxa of M. fimbriata . Material and methods – The study was based on a combination of morphological and molecular phylogenetic analyses of the clonal strains and natural populations. Key results and conclusions – In this study, we present formal taxonomic description of Micrasterias compereana for specimens formerly included within traditional M. fimbriata, but differring in their phylogenetic position and discriminative morphological characteristics. Phylogenetic analysis was based on the nuclear 18S rDNA and the plastid-encoded trnG UCC intron sequence data. Morphological differences between species were illustrated by light and scanning electron microscopy. The analysis of natural samples, strains and published records showed that M. compereana occurs in North America and western Europe. Conversely, M. fimbriata sensu stricto probably only occurs in temperate and boreal regions of Europe and Asia

Everything is NOT everywhere: network and trait-based approaches to microbial communities

International audienc

Ecological and biogeographical drivers of freshwater green algae biodiversity: from local communities to large-scale species pools of desmids

International audienc

Molecular diversity of green corticolous microalgae from two sub-Mediterranean European localities

<div><p>Green algae in corticolous biofilms are simple coccoid cells or filamentous thalli with strikingly low morphological diversity. Consequently, microscopic identification of these organisms is difficult, and often possible only to higher taxonomic units. We investigated the taxonomic and phylogenetic composition of green microalgae isolated from biofilms growing on the bark of <i>Quercus pubescens</i> and <i>Pinus nigra</i>. The study was based on 122 partial sequences of the plastid-encoded <i>rbc</i>L gene. In total, 29 operational taxonomic units (OTUs), differing in their <i>rbc</i>L sequences, were encountered. Members of the Trebouxiophyceae formed 97.5% of the isolates; Streptophyta made up 2.5%. The most frequently occurring OTUs were in the genera <i>Coccomyxa, Parachloroidium</i> and <i>Stichococcus</i>. Within the <i>Watanabea</i> clade, we have probably discovered an as-yet undescribed generic lineage with chlorelloid morphology. OTUs belonging to the recently described trebouxiophycean genera <i>Kalinella, Leptochlorella</i> and <i>Xylochloris</i> were also encountered, which indicates that these genera are probably widely distributed in subaerial microhabitats, such as tree bark. The samples taken from oak trees were more diverse in their OTU composition than those taken from pine trees, but the average phylogenetic distances of OTUs in samples did not differ between the host tree taxa. Host tree species had a stronger effect on the community structure of algae than the sampling locality. This indicates that habitat filtering is important for the distribution of individual microalgal phylogenetic taxa.</p></div