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Diversity of Epilobium and methods to explore their hybridization
Kuchyňková, Lenka ; Kaplan, Zdeněk (advisor) ; Šemberová, Kristýna (referee)
Willowherbs (Epilobium) belong to the genera whose evolution is significantly affected by interspecific hybridization. Although this process often generates evolutionary novelties and leads to speciation, it can also result in genetic erosion and extinction. This thesis is mainly focused on the Czech Epilobium species that are potentially endangered by interspecific hybridization. The emphasis falls on the group of rare mountain willowherbs including E. nutans, E. alsinifolium and E. anagallidifolium. In addition to frequent interspecific hybridization, the research of this group is also complicated by the subtlety of distinguishing morphological features. The review also summarizes the available methods that can be used to study interspecific hybridization in the follow-up thesis.
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Population structure and evolutionary history of Central European bellflowers from the Campanula rotundifolia agg.
Šemberová, Kristýna
6 Abstract For understanding extant species diversity, knowledge about processes acting at the population level is crucial. Besides mutations generating de novo genetic variation, three major processes, i.e., polyploidy, hybridization and local adaptation, notably impact population structure and cause evolutionary novelty. Campanula rotundifolia agg. was chosen as a model group for the joint study of these processes because it represents a polyploid complex with three major cytotypes (2x, 4x, 6x), a hitherto unknown ability to hybridize, and a pleiad of putative species that have undergone local adaptation to different conditions. In particular, polyploidization in the complex is acknowledged for generating morphological variation, facilitating long-distance dispersal and shifts in the environmental niche. It also creates a reproductive barrier, thus enabling sympatric speciation. Prerequisites for local adaptation are morphological variation and strong selection pressures leading to adaptive divergence and the rise of many endemic taxa, mainly at the extremes of environmental gradients. On the other hand, for locally adapted or endemic taxa, hybridization with a widespread taxon is one of the main existential threats. Here, I focused on C. rotundifolia agg. populations in Central Europe its hypothetical...
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Population structure and evolutionary history of Central European bellflowers from the Campanula rotundifolia agg.
Šemberová, Kristýna ; Schmickl, Roswitha Elisabeth (advisor) ; Tribsch, Andreas (referee) ; Štech, Milan (referee)
6 Abstract For understanding extant species diversity, knowledge about processes acting at the population level is crucial. Besides mutations generating de novo genetic variation, three major processes, i.e., polyploidy, hybridization and local adaptation, notably impact population structure and cause evolutionary novelty. Campanula rotundifolia agg. was chosen as a model group for the joint study of these processes because it represents a polyploid complex with three major cytotypes (2x, 4x, 6x), a hitherto unknown ability to hybridize, and a pleiad of putative species that have undergone local adaptation to different conditions. In particular, polyploidization in the complex is acknowledged for generating morphological variation, facilitating long-distance dispersal and shifts in the environmental niche. It also creates a reproductive barrier, thus enabling sympatric speciation. Prerequisites for local adaptation are morphological variation and strong selection pressures leading to adaptive divergence and the rise of many endemic taxa, mainly at the extremes of environmental gradients. On the other hand, for locally adapted or endemic taxa, hybridization with a widespread taxon is one of the main existential threats. Here, I focused on C. rotundifolia agg. populations in Central Europe its hypothetical...
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What we know about salty ecosystems of the Europe and their distribution, origin and history?
Šemberová, Kristýna ; Stančík, Daniel (advisor) ; Špryňar, Pavel (referee)
Salt marsh and meadow vegetation belong to very specific type of azonal ecosystem. There develop is made possible because of high concentrations of salts in the substrate. On the coast the development results from the contact of shore area with seawater. The existence of inland salt meadow is depending on specific climatic, geological and pedological conditions. Plants (halophytes) developed specific types of adaptation to resist high level of salinity and other extreme conditions of their habitat. During evolution occurred this type of adaptation in several phylogenetic lineages independently. Structure and physiognomy of salt marsh and meadow vegetation depend on the degree of salinity of the substrate and we can distinguish several zones on this gradient. Climatic conditions during the pleniglacial were very favourable for the development of halophyte vegetation. The oldest salt marshes, which played role of the refuge, are located on the coast, but also in the inland of Central Asia. This kind of vegetation reaches also south part of Central and Eastern Europe. After glaciation and the arrival of the forest, big part of this vegetation disappeared. Some inland areas have been maintained thanks to a man, which has used them since Neolithic times as pastures. With the abolition of grazing,...
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Searching for the origin of high-altitude endemic harebells from Campanula rotundifolia agg. in central Europe.
Folbrová, Magdaléna ; Šemberová, Kristýna (advisor) ; Trávníček, Pavel (referee)
Complex Campanula rotundifolia agg. is rich in endemic species, especially in the high- elevated mountain ranges. Extreme climatic conditions in the subalpine habitats can lead to a convergence in plant's morphology between plants isolated in different mountain ranges. Because of the lack of morphological differentiation, it is very difficult to reconstruct the evolutionary history of bellflowers C. scheuchzeri from the Alps, C. bohemica from the Krkonoše Mountains and C. tatrae from the Western Carpathians. A similarity in morphology and the same ploidy level can suggest vicariance from a large area of an ancestor species. However, regarding the continuous morphological variation, the high-altitudinal endemics could have originated by local adaptation from originally low-land species. DNA-ploidy level and genome size were detected by flow cytometry. Taxonomically important characters were found using multivariate morphometric analysis. The phenotypic plasticity of the taxon C. tatrae was tested by a cultivation experiment. Genetic structure of the studied species was revealed using molecular marker - microsatellites (7 variable primers). Studied taxa were tetraploids, but some possessed different genome size. The morphological differentiation was mainly due to characters like calyx lobes length...
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The role of high-altitude habitats for speciation of central European endemics from the genus Campanula
Folbrová, Magdaléna ; Šemberová, Kristýna (advisor) ; Reif, Jiří (referee)
Mountain environment plays an important role in plant's life. Extreme conditions lead to continuous speciation accompanied by a complex processes e.g. geographical isolation (variation) or polyploidization. These processes can be studied by using a suitable model plant, represented in this thesis by selected mountain endemic bellflowers species belonging to Campanula rotundifolia agg. These species appear to be morphologically very similar but they are supposed to be of different origin. Mountain ecosystem is considered to be one of the most diverse and the most valuable environment for nature conservation. It hosts many endangered plants as well as plants protected by law. From the model group, these plants are represented by Campanula bohemica Hruby, Campanula gelida Kovanda and Campanula rotundifolia subsp. sudetica (Hruby) Soó. This thesis aims to sum up the up the current knowledge about a high altitude environment and endemism and to give a description of speciation mechanisms leading to the variability of mountain Campanula species. Further descriptions of their endangerment level, conservation and origin are also given. The subsequent MSc Thesis, introduced in the last part of this thesis, aims to reveal the origin of Czech and Slovakian mountain Campanula endemics. It is mainly focused on...
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Population cytotype structure and phenotypic variation of Campanula moravica
Šemberová, Kristýna ; Suda, Jan (advisor) ; Mráz, Patrik (referee)
Polyploidisation plays a major role in plant evolution. It can also cause taxonomic complexities as morphological differences are often blurred in higher ploidy levels. One of the taxonomically-intrigued groups of Central Europe is C. rotundifolia agg. Three ploidy- heterogeneous species are traditionally recognized in the Czech Republic: C. gentilis (2x, 4x), C. rotundifolia (2x, 4x) and C. moravica (4x, 6x). The thesis examines karyological and phenotypic variation of C. moravica, in the centre of its distribution (the Czech Republic and Slovakia). With the aid of modern biosystematics tools (DNA flow cytometry, multivariate morphometrics), marked discrepancies were revealed between published data and actual cytotype distribution pattern and morphological variation. In contrast to literature records, cytotype distribution in C. moravica is largely parapatric, with hexaploids occurring in Pannonian basin and tetraploids in Central and Eastern Slovakia. The type population of presumed tetraploids turned out to be hexaploid. The coexistence of one majority (4x) and six minority cytotypes (2x, 3x, 5x, 6x, 8x, 9x) was found in one population in central Slovakia and represent the most salient case of ploidy coexistence ever reported. Multivariate morphometrics showed that species identification on the...
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What we know about salty ecosystems of the Europe and their distribution, origin and history?
Šemberová, Kristýna ; Stančík, Daniel (advisor) ; Špryňar, Pavel (referee)
Salt marsh and meadow vegetation belong to very specific type of azonal ecosystem. There develop is made possible because of high concentrations of salts in the substrate. On the coast the development results from the contact of shore area with seawater. The existence of inland salt meadow is depending on specific climatic, geological and pedological conditions. Plants (halophytes) developed specific types of adaptation to resist high level of salinity and other extreme conditions of their habitat. During evolution occurred this type of adaptation in several phylogenetic lineages independently. Structure and physiognomy of salt marsh and meadow vegetation depend on the degree of salinity of the substrate and we can distinguish several zones on this gradient. Climatic conditions during the pleniglacial were very favourable for the development of halophyte vegetation. The oldest salt marshes, which played role of the refuge, are located on the coast, but also in the inland of Central Asia. This kind of vegetation reaches also south part of Central and Eastern Europe. After glaciation and the arrival of the forest, big part of this vegetation disappeared. Some inland areas have been maintained thanks to a man, which has used them since Neolithic times as pastures. With the abolition of grazing,...
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