National Repository of Grey Literature 5 records found  Search took 0.02 seconds. 
Species delimitation in Aspergillus section Candidi
Glässnerová, Kateřina ; Hubka, Vít (advisor) ; Caboň, Miroslav (referee)
Aspergillus section Candidi encompasses white- or yellow-sporulating species mostly isolated from indoor and cave environments, soil, food, feed, clinical material and dung. Their identification is non-trivial due to largely uniform morphology. This work aims to re- evaluate the species boundaries in the section Candidi and present an overview of all existing species along with information on their ecology. For this work, a set of 113 strains of different origins was gathered. DNA sequences of the genes for β-tubulin (benA), calmodulin (CaM), and the second largest subunit of RNA polymerase (RPB2) were used for molecular analyses, and species delimitation methods based on a multispecies coalescent model were applied. Classical phylogenetic methods and the genealogical concordance species recognition approach were used for comparison. Phenotypic studies involved comparisons of macromorphology on four cultivation media, seven micromorphological characters and growth in temperatures ranging from 10 to 45 řC. For the final decision about species boundaries, an integrative approach consisting of four criteria was defined, based on which seven existing and two undescribed species were supported. The revised section Candidi comprises nine species, some of which manifest a high level of intraspecific...
Species limits within Aspergillus section Restricti inferred from multiple gene phylogenies and phenotype analysis
Sklenář, František ; Hubka, Vít (advisor) ; Janko, Karel (referee)
Section Restricti is one of the last sections of the genus Aspergillus that hasn't been revised in the modern taxonomic era. All species are osmophilic, have simple morphology and they are mainly important because of the food, feed and seed spoilage, some of them also have negative influence to the indoor air. The section consists of seven species according to the last taxonomic revision from 2008 based only on molecular data. It currently consists of six asexual and one homothalic species. 126 isolates from the section coming from four continents were studied in this thesis, including ex-type strains. Revision of the section was carried out combining molecular phylogenetic analysis and conventional taxonomic methods. Modern methods of species delimitation based on multispecies coalescent model were used for the phylogenetic reconstruction. From the conventional methods analysis of morphology (macro- and micromorphology including scanning electron microscopy) and physiology (ability of growing in osmotic gradient and several different temperatures) was performed. Apart from the seven known species, eight new undescribed species were discovered. Majority of the new species belongs to the Aspergillus penicillioides species complex. Key words: Aspergillus restrictus, osmophilic fungi, species...
Species delimitation in lobose amoebae
Foučková, Martina ; Čepička, Ivan (advisor) ; Škaloud, Pavel (referee)
Lobose amoebae - amoebas that create lobopodia - are distributed among the supergroup Amoebozoa, Excavata, Rhizaria and the genus Anaeramoeba (Eukaryota incertae sedis). For their species delimitation (i.e., pinpointing boundaries between particular species), morphological features are used most often, such as the size and shape of the cell, appearance of the hyaloplasm, pseudopodia and subpseudopodia, granuloplasm with cytoplasmatic inclusions, number and size of nuclei, shape of the uroid and cysts if present. The morphological characteristics are easily documented using a light microscope. Ultrastructural features, such as the ultrastructure of nuclei and nucleoli, surface structures, and organelles, are used as well. Nowadays, species are also described and distinguished employing molecular methods, mostly analyses of the SSU rRNA and actin genes, COI barcoding, and ITS sequences, which allow detection of cryptic species. Before the sequencing era, RFLP, RAPD and isozymes methods were also used for delimitation of species. This thesis focuses on particular methods and features used for species delimitation of lobose amoebae on the basis of 125 selected species belonging to Amoebozoa (orders Acanthamoebida, Pellitida, Himatismenida, Dermamoebida, Thecamoebida, Vannellida, Dactylopodida,...
Species limits within Aspergillus section Restricti inferred from multiple gene phylogenies and phenotype analysis
Sklenář, František ; Hubka, Vít (advisor) ; Janko, Karel (referee)
Section Restricti is one of the last sections of the genus Aspergillus that hasn't been revised in the modern taxonomic era. All species are osmophilic, have simple morphology and they are mainly important because of the food, feed and seed spoilage, some of them also have negative influence to the indoor air. The section consists of seven species according to the last taxonomic revision from 2008 based only on molecular data. It currently consists of six asexual and one homothalic species. 126 isolates from the section coming from four continents were studied in this thesis, including ex-type strains. Revision of the section was carried out combining molecular phylogenetic analysis and conventional taxonomic methods. Modern methods of species delimitation based on multispecies coalescent model were used for the phylogenetic reconstruction. From the conventional methods analysis of morphology (macro- and micromorphology including scanning electron microscopy) and physiology (ability of growing in osmotic gradient and several different temperatures) was performed. Apart from the seven known species, eight new undescribed species were discovered. Majority of the new species belongs to the Aspergillus penicillioides species complex. Key words: Aspergillus restrictus, osmophilic fungi, species...
Taxonomy of selected groups of the genus \kur{Caloplaca}
ŠOUN, Jaroslav
The thesis deals with phylogeny, taxonomy and nomenclature of selected groups of the lichen genus Caloplaca. Particularly, the C. cerina group was closely investigated using molecular methods (ITS sequences), morphology and chemistry, based on material from Europe, and to some extent also from North America and western Asia. This approach resulted in the description of three new species (C. sterilis, C. subalpina, C. thracopontica), and detected an unexpected richness of lineages. Nomenclature, taxonomy, morphology and ecology of C. aurantia and C. flavescens from the C. aurantia group were studied in detail, including selection of the neotype of the former species. Their distribution was reviewed for the territory of the Czech Republic. Poorly known taxon C. aurantiomurorum from Algeria was lectotypified and synonymized with C. aurantia. Apart from the two groups, C. phlogina and C. scythica, differing partly in thallus colour and distinctly in distribution, were examined using both molecular (ITS sequences) and phenotypic data and found to be conspecific.

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