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Phylogeographic patterns and microevolutionary mechanisms in oceanic dolphins
Křišťanová, Žaneta ; Hulva, Pavel (advisor) ; Vokurková, Jana (referee)
This bachelor thesis discusses the current findings regarding the phylogeography of the Delphinidae family. It is mainly focused on phylogenetic structure and speciation of Delphinidae, as well as on the ways of differentiation of trophic niches and the evolution of ecotypes. In the past, the Pleistocene climate oscillation had a major influence on the development of individual species and populations. Currently, it is anthropogenic activities that cause fundamental changes in habitats and thereby change the living conditions for cetaceans. In several species of Delphinidae, the emergence of ecotypes has been recorded, where different populations of the same species use different ecological niches. This thesis is mainly dedicated to the ecotypes of the bottlenose dolphin (Tursiops truncatus). Variability in coloration, body length and spine morphology was noted for individual ecotypes. The spine is an important adaptation to the environment in Delphinidae. In this research, phylogenetic relationships between family of Delphinidae, life strategies and food niche of selected species of the genera Tursiops, Stenella and Delphinus are also described.
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Use of laboratory and image spectroscopy to evaluate drought resistance of Scots pine and to distinguish its ecotypes
Raasch, Filip ; Kupková, Lucie (advisor) ; Potůčková, Markéta (referee)
The aim of this study was to propose a non-destructive method for measuring Pinus sylvestris seedlings, to determine whether water stress would be evident in laboratory spectra of pines, to compare whether the response of pines would differ by ecotype, and to investigate whether two ecotypes of Pinus sylvestris could be distinguished using laboratory and image spectroscopy. For these purposes, hyperspectral images of seed orchards from August 2020 were processed and a three-month laboratory experiment was conducted, in which stress from water deficit was induced in two-year-old pine seedlings from the upland and hilly ecotypes. Spectral data were analysed using mixed statistical models, analysis of variance, principal component analysis, training of supervised pixel classifiers, vegetation indices, and linear regression. Based on the analyses, it was found that water stress can be detected in severely stressed Pinus sylvestris seedlings. The most sensitive spectral bands to water content were observed in the region between 1000-2500 nm. The initial response to water stress did not differ by ecotype, but a faster recovery was observed at the upland ecotype after the period of draught. The two Pinus sylvestris ecotypes were distinguished with high accuracy from both laboratory and image spectral...
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Stabilita membrán jako měřítko odolnosti vůči chladovému stresu u kontrastních ekotypů Arabidopsis thaliana
Kopytko, Valeriia
Cold acclimation is a process of adaptation to suboptimal temperatures preparing the plants to efficiently reduce the upcoming damage that may be caused by sub-zero temperature. The early phase of cold acclimation is associated with stimulation of the protective mechanisms and fast suppression of growth. This work was focused on the comparison of the effect of normal and low light intensity on the stability of the membrane in Arabidopsis plants during the cold acclimation period. Ion conduc-tivity is a sensitive method that directly evaluates the impact of stress on plant fitness and thus, we used the electrolyte leakage method for assessing cell membrane stability to test the cold stress tolerance. Next, we will focus on the natural variation of stress responses in a broad spectrum of Arabidopsis ecotypes to dissect genetic traits confer-ring the plants with a tolerance to cold and freezing stress. During the monitoring of expression profiles of the cold signaling pathway genes for various resistant ecotypes it was found, that ecotype C24 is sensitive to low temperatures, although it shows sig-nificant tolerance to other stresses. The Tamm-2 ecotype, conversely, shows a high level of cold and frost tolerance and has a high expression of cold signaling genes. Cold tol-erance correlated with expression of genes that contribute to low temperature responses: CBF1, CBF2, CBF3, and COR47.
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Phylogeography and adaptive evolution of the grey wolf
Veselovská, Lenka ; Hulva, Pavel (advisor) ; Fornůsková, Alena (referee)
Grey wolf is a highly mobile top predator, a keystone and umbrella species within ecosystems throughout the Holarctic area. The occurrence of wolves' populations is influenced by glacial history, environmental conditions and human activity. Nowadays, wolves are returning to a man-altered country where they were exterminated, and they are adapting to human dominated landscape. People have largely contributed to its extinction in many areas around the world, resulting in a decline in genetic diversity. Due to different demographic and environmental conditions, many different lineages have evolved, which can be distinguished based on morphological and genetic analyses. Climatic factors can result in the formation of ecotypes, which become heritable and genetically distinguishable. The aim of this thesis is to provide a comprehensive overview of the phylogeography and adaptive evolution of the grey wolf in the context of genetic, geographical and morphological combination data. Keywords: grey wolf, Canis lupus, phylogeography, ecotypes, adaptive evolution
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Biosystematic studies in the family Cyperaceae
KOŠNAR, Jan
The thesis was focused on the microevolutionary mechanisms that contribute to morphological diversity in selected members of the sedge family (Cyperaceae). Natural hybridization, evidenced from both morphological characters and molecular markers, was revealed to be a potentially important source of diversification in the tropical spikerushes of Eleocharis subgenus Limnochloa. High levels of phenotypic plasticity of clonal growth but rare genetic (ecotypic) differentiation among contrasting morphotypes were found in the polymorphic species Carex nigra, which implied that taxonomic splitting of the species was unreasonable.
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