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Phylogenetic, morphological and ecological context of microevolution in pennate diatoms
Veselá, Jana ; Neustupa, Jiří (advisor) ; Řeháková, Klára (referee) ; Vanormelingen, Pieter (referee)
Visual assessment of discontinuities in the morphological features of diatom cells has been widely used in the discovery and delimitation of diatom species. However, a multidisciplinary approach to species-level taxonomy has revealed hidden diversity within the traditional diatom morphospecies. Consequently, this work examined both the natural and clonal populations of diatoms by diverse traditional and modern approaches, in order to assess the diversity, ecology, and distribution of diatom species. Although a detailed investigation of natural diatom samples was confounded by uncertain morphological boundaries between the traditional diatom species, it recognized that the diversity was relatively high; even one new diatom species was described using the morphological species concept. The multivariate statistical analyses showed that the variation of natural communities of traditional diatom morphospecies reflected differences in the local environmental conditions, as well as microhabitat heterogenity within a region. Since each diatom morphospecies is most likely a complex of sibling species, the two model traditional morphospecies were investigated, in order to assess morphological variation, genetic diversity, and/or the reproductive compatibility of monoclonal cultures. Even though isolated...
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Genetic diversity and evolutionary history of Czech endemic taxa from the genus Dianthus
Kalůsková, Jana ; Suda, Jan (advisor) ; Chrtek, Jindřich (referee)
Abstract This MSc. thesis deals with karyological, genetic and phenotypic variation of selected taxa from the genus Dianthus L. in the Czech Republic and adjacent countries. The evolutionary history of the genus has been shaped by several microevolutionary processes, including interspecific hybridization, genome duplication, and edaphic speciation. These processes led to the origin of a number of phenotypically similar taxa, which are often restricted to a narrow geographic area. One subendemic and three endemic taxa occur in the Czech Republic. These (sub)species were used as model groups to gain insight into microevolutionary processes in small populations and the postglacial development of the genus in Central Europe. The thesis consists of three parts, each addressing different evolutionary phenomenon: Dianthus arenarius subsp. bohemicus is a critically endangered endemic psammophyte currently known from a single population in Central Bohemia. The site is also inhabited by widespread D. carthusianorum. Interspecific hybridization has been suspected on the basis of morphological characters, but this has never been confirmed by any other technique. I exploited differences in the number of chromosomes between both species and, with the aid of DAPI flow cytometry, estimated relative DNA contents of...
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Variation of the species Urtica dioica in Central Europe
Rejlová, Ludmila ; Urfus, Tomáš (advisor) ; Mandák, Bohumil (referee)
Although the European flora belongs to the best explored at the global scale, still there are several largely neglected plant groups, which may surprise by marked variation. One of these groups is Urtica dioica s. l., consisting of vaguely described taxa (microspecies / subspecies) with indefinite distribution. The most important source of variation in U. dioica s. l. is probably polyploidy (2x, 4x; x = 13). The complex comprises an ubiquitous tetraploid cytotype (U. dioica s. str.) and several obscurely defined relict 2x taxa. The cytogeographical analysis through Europe (770 populations / over 3 200 individuals) revealed marked distribution pattern of U. dioica s. l. cytotypes. We identified 106 diploid populations (13%) and 633 (82%) tetraploid populations. For the first time we detected triploid and pentaploid level (from mixed populations). Prevailing tetraploid U. dioica s. str. is predominantly synanthropic, whereas diploid taxa strictly occur in primary and relict habitats (primarily alluvial forests, tundra, Mediterranean mountains). The analysis of the absolute genome size of individuals from U. dioica clade and other closely related taxa showed different values of 2x U. kioviensis (19 % higher than 2x U. d. subsp. subinermis) and 2x U. bianorii (33% higher than 2x U. d. subsp....
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Ecological consequences of polyploidization in populations of the wetland plant Butomus umbellatus
Rydlo, Jan ; Fér, Tomáš (advisor) ; Trávníček, Pavel (referee)
This thesis aimed on comparison of environmental requirements and morphological and biological traits of diploid and triploid cytotypes of wetland plant flowering rush (Butomus umbellatus), occurring in Eastern Slovak Lowland in unique mixed populations, and to develop primers for variable microsatellite loci suitable for further genetic studies. In total, 72 populations of Butomus umbellatus were found. The analysis of relative genome size by the flow cytometry (FCM) technique revealed 34 exclusively triploid cytotype populations, 8 exclusively diploid populations and 30 mixed populations of Butomus umbellatus. In mixed populations, the numbers of diploid and triploid individuals are quite equivalent and the plants create combined compact communities. Analyses of environmental characteristics of sites with specific cytotypes (PCA, RDA, ANOVA) revealed no difference in site requirements of diploid and triploid Butomus umbellatus plants. Morphometric analyses (PCA, CDA) of traits of 36 diploid and 54 triploid plants confirmed differing morphology of both cytotypes occurring in the nature. Subsequent replanting of these plants into pots and cultivation further increased these differences. The ratio of width and length of internal perianthium is the most reliable parameter to distinguish diploid and...
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Genetic diversity and evolutionary history of Czech endemic taxa from the genus Dianthus
Vítová, Jana
This MSc. thesis deals with karyological, genetic and phenotypic variation of selected taxa from the genus Dianthus L. in the Czech Republic and adjacent countries. The evolutionary history of the genus has been shaped by several microevolutionary processes, including interspecific hybridization, genome duplication, and edaphic speciation. These processes led to the origin of a number of phenotypically similar taxa, which are often restricted to a narrow geographic area. One subendemic and three endemic taxa occur in the Czech Republic. These (sub)species were used as model groups to gain insight into microevolutionary processes in small populations and the postglacial development of the genus in Central Europe. The thesis consists of three parts, each addressing different evolutionary phenomenon: Dianthus arenarius subsp. bohemicus is a critically endangered endemic psammophyte currently known from a single population in Central Bohemia. The site is also inhabited by widespread D. carthusianorum. Interspecific hybridization has been suspected on the basis of morphological characters, but this has never been confirmed by any other technique. I exploited differences in the number of chromosomes between both species and, with the aid of DAPI flow cytometry, estimated relative DNA contents of most...
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An assessment of interspecific hybridization between Central-European taxa from the genus Nymphaea: insights from flow cytometry and multivariate morphometrics
Kabátová, Klára
Although the genus Nymphaea (waterlily) includes only two native species (N. alba and allopolyploid N. candida) in Central Europe, it poses a great challenge to taxonomy and biosystematics. The determination of both species is hampered by their phenotypic similarities, and species boundaries can be further blurred by interspecific hybridization. In addition, ornamental cultivars of different parentage that often escape (either accidentally or intentionally) from cultivation and can cross with the native ones make the situation even more complex. To get insight into the caryological and phenotypic variability of czech waterlilies, we used DNA flow cytometry and both distance-based and geometric morphometrics. Collections from natural sites showed two different groups of fluorescence intensities, corresponding to N. alba and N. candida, respectively. In addition, intermediate values of nuclear DNA amount were found in some plants from South Bohemia, indicating their hybrid origin. Morphologically, these plants were partly intermediate between the native species, partly having their separate tendency to oversized growth. Surprisingly, ornamental cultivars (obtained either from commercial stocks or as escapes from the field) possessed the smallest genome sizes. The amount of nuclear DNA therefore seems...
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Postnatal Ontogenesis of the Skull of the Pond Slider Turtle (Trachemys scripta)
Čtrnáctová, Lenka ; Brejcha, Jindřich (advisor) ; Soukup, Vladimír (referee)
This thesis focuses on the descriptive analysis of skull morphology of the pond slider turtle (Trachemys scripta elegans). The general approach was an osteological preparation of the skulls and photographic documentation (following standardised procedures) of a larger sample of specimens. The collected data was used as a background for subsequent GMM analyses. Main hypotheses of this project were: 1) the skull of T. s. elegans is sexually dimorphic; 2) the skull of T. s. elegans constitutes of several independent modules. The objective of this thesis was therefore to describe the postnatal ontogenesis of the model taxon and to determine the developmental trends of its cranial structures. It was shown that the skull of T. s. elegans is sexually dimorphic in shape mainly due to differences in allometric growth. These differences probably reflect different nutritional requirements. The skull of T. s. elegans is formed out of four modules. These are: facial, central, basicranial, and possibly also zygomatic-pterygoideal modules.
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Genetic diversity and evolutionary history of Czech endemic taxa from the genus Dianthus
Vítová, Jana
This MSc. thesis deals with karyological, genetic and phenotypic variation of selected taxa from the genus Dianthus L. in the Czech Republic and adjacent countries. The evolutionary history of the genus has been shaped by several microevolutionary processes, including interspecific hybridization, genome duplication, and edaphic speciation. These processes led to the origin of a number of phenotypically similar taxa, which are often restricted to a narrow geographic area. One subendemic and three endemic taxa occur in the Czech Republic. These (sub)species were used as model groups to gain insight into microevolutionary processes in small populations and the postglacial development of the genus in Central Europe. The thesis consists of three parts, each addressing different evolutionary phenomenon: Dianthus arenarius subsp. bohemicus is a critically endangered endemic psammophyte currently known from a single population in Central Bohemia. The site is also inhabited by widespread D. carthusianorum. Interspecific hybridization has been suspected on the basis of morphological characters, but this has never been confirmed by any other technique. I exploited differences in the number of chromosomes between both species and, with the aid of DAPI flow cytometry, estimated relative DNA contents of most...
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An assessment of interspecific hybridization between Central-European taxa from the genus Nymphaea: insights from flow cytometry and multivariate morphometrics
Kabátová, Klára
Although the genus Nymphaea (waterlily) includes only two native species (N. alba and allopolyploid N. candida) in Central Europe, it poses a great challenge to taxonomy and biosystematics. The determination of both species is hampered by their phenotypic similarities, and species boundaries can be further blurred by interspecific hybridization. In addition, ornamental cultivars of different parentage that often escape (either accidentally or intentionally) from cultivation and can cross with the native ones make the situation even more complex. To get insight into the caryological and phenotypic variability of czech waterlilies, we used DNA flow cytometry and both distance-based and geometric morphometrics. Collections from natural sites showed two different groups of fluorescence intensities, corresponding to N. alba and N. candida, respectively. In addition, intermediate values of nuclear DNA amount were found in some plants from South Bohemia, indicating their hybrid origin. Morphologically, these plants were partly intermediate between the native species, partly having their separate tendency to oversized growth. Surprisingly, ornamental cultivars (obtained either from commercial stocks or as escapes from the field) possessed the smallest genome sizes. The amount of nuclear DNA therefore seems...
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Ecological consequences of polyploidization in populations of the wetland plant Butomus umbellatus
Rydlo, Jan ; Fér, Tomáš (advisor) ; Trávníček, Pavel (referee)
This thesis aimed on comparison of environmental requirements and morphological and biological traits of diploid and triploid cytotypes of wetland plant flowering rush (Butomus umbellatus), occurring in Eastern Slovak Lowland in unique mixed populations, and to develop primers for variable microsatellite loci suitable for further genetic studies. In total, 72 populations of Butomus umbellatus were found. The analysis of relative genome size by the flow cytometry (FCM) technique revealed 34 exclusively triploid cytotype populations, 8 exclusively diploid populations and 30 mixed populations of Butomus umbellatus. In mixed populations, the numbers of diploid and triploid individuals are quite equivalent and the plants create combined compact communities. Analyses of environmental characteristics of sites with specific cytotypes (PCA, RDA, ANOVA) revealed no difference in site requirements of diploid and triploid Butomus umbellatus plants. Morphometric analyses (PCA, CDA) of traits of 36 diploid and 54 triploid plants confirmed differing morphology of both cytotypes occurring in the nature. Subsequent replanting of these plants into pots and cultivation further increased these differences. The ratio of width and length of internal perianthium is the most reliable parameter to distinguish diploid and...
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