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Glycerolipids and carotenoids in microalgae: the implications in ecophysiology and applied phycology
Střížek, Antonín ; Nedbalová, Linda (advisor) ; Brányiková, Irena (referee) ; Barreira, Luísa (referee)
Lipids are basic biomolecules found in all organisms. They have a key function as structural molecules forming cell membranes, and, in the form of fats and oils, energy is also stored. There are a huge number of lipid types that have other functions, for example, in cell signaling, enzyme support, protection against stress, and others. Microscopic algae are the main primary producers in both freshwater and marine ecosystems. Therefore, algal biosynthesis has a fundamental effect on the trophic networks of aquatic ecosystems and ultimately on humans. The environment affects the ecophysiology of algae, which is reflected in their biochemical composition, i.e. in the composition of their lipids. This work is focused on two groups of lipids, namely glycerolipids, which consist of fatty acids, and carotenoids, which are photosynthetic pigments with antioxidant and photoprotective properties. In these groups of lipids, the target substances were further selected, namely polyunsaturated fatty acids and the carotenoid fucoxanthin belonging to xanthophylls. These substances are important not only in the ecophysiology of algae, but they are valuable substances that have positive effects on the human organism and, with the help of optimized cultivation, could be obtained from algae for industrial production...
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Condition dependence of sexually selected ornaments in birds
Tomášek, Oldřich ; Albrecht, Tomáš (advisor) ; Verhulst, Simon (referee) ; Šálek, Miroslav (referee)
Sexual ornaments important for mating success in many species are often assumed to evolve as condition-dependent signals of individual quality. Ornament expression can be associated with age and survival, thereby signalling individual viability. Here, we have tested viability signalling function of tail streamers and their importance for within-pair and extra-pair fertilisation success in the European barn swallow (Hirundo rustica rustica). In contrast to previous studies on this subspecies, our data suggest that tail length is not associated with fertilisation success in our population. Instead, the most important predictors of within-pair and extra-pair fertilisation success were female and male age, respectively. Our data supported viability signalling function of male tail streamers, as documented by age-related within- individual increase in their length. There was no evidence for senescence in this trait. Contrary to some previous studies, the viability signalling function of tail streamers was further supported by observed selective disappearance of males with shorter tails. Several physiological mechanisms have been proposed as maintaining signalling honesty. Among them, oxidative stress from highly reactive species (RS), including free radicals, attracted a considerable attention. Given...
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Determination of stress of Norway spruce by direct methods
Krejza, Jan ; Světlík, J. ; Bellan, Michal ; Horáček, Petr
The aim of this methodology is to introduce methods of forest ground monitoring leading to evaluation of Norway spruce tree vitality. Certified methodology describes: measuring of the stem surface temperature by thermography, measuring of the sap flow, measuring the stem diameter fluctuation and by the analysis of xylogenesis and wood morphology. Emphasis was placed on the detection of the stress reaction before occurrence of the visual symptoms. The aim of this methodology is to present a comprehensive set of methods for measuring ecopysiological activity of a tree and to determine its health status. The goal of this methodology is to provide a unique tools for foresters and for forest management for direct and precise evaluation of health status of individual trees, but also a whole complexes of forest from the ground perspective. The individual methodological approaches are defined, can be used in practice and their interpretation is unambiguous. The novelty is based on the direct measurement of the physiological activity of the individual trees, which exclude any degree of subjectivity in the evaluation process.
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Condition dependence of sexually selected ornaments in birds
Tomášek, Oldřich ; Albrecht, Tomáš (advisor) ; Verhulst, Simon (referee) ; Šálek, Miroslav (referee)
Sexual ornaments important for mating success in many species are often assumed to evolve as condition-dependent signals of individual quality. Ornament expression can be associated with age and survival, thereby signalling individual viability. Here, we have tested viability signalling function of tail streamers and their importance for within-pair and extra-pair fertilisation success in the European barn swallow (Hirundo rustica rustica). In contrast to previous studies on this subspecies, our data suggest that tail length is not associated with fertilisation success in our population. Instead, the most important predictors of within-pair and extra-pair fertilisation success were female and male age, respectively. Our data supported viability signalling function of male tail streamers, as documented by age-related within- individual increase in their length. There was no evidence for senescence in this trait. Contrary to some previous studies, the viability signalling function of tail streamers was further supported by observed selective disappearance of males with shorter tails. Several physiological mechanisms have been proposed as maintaining signalling honesty. Among them, oxidative stress from highly reactive species (RS), including free radicals, attracted a considerable attention. Given...
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Effects of abiotic factors on hemiparasitic plants
SVĚTLÍKOVÁ, Petra
This thesis focuses on the ecophysiology of hemiparasitic plants. In its introduction, I review our understanding of abiotic factor effects on root and stem hemiparasites and highlight gaps in our knowledge which would be interesting to explore in future. The following four chapters are first author articles that investigate responses of selected root hemiparasites from the rhinanthoid clade of Orobanchaceae to varying availability of abiotic factors such as light, water, and mineral nutrients.
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Ecophysiological differentiation of Synura petersenii cryptic species (Synurophyceae)
Jelínková, Lucie ; Škaloud, Pavel (advisor) ; Elster, Josef (referee)
Synura petersenii represents a complex of pseudo-cryptic species. These are planktonic colonial organisms belonging to the class Chrysophyceae. The species are abundant in spring and autumn, when they produce golden-brown blooms in oligo-mesotrophic waters. In this thesis, I focused on investigating the effect of temperature to growth parameters of four selected species: S. petersenii, S. americana, S. glabra and S. conopea. Several temperature experiments were performed and statistically analyzed. According to growth curves the temperature 25 žC was mostly stressful for these organisms. Only S. petersenii sensu stricto was sometimes able to growth at this temperature. In general, the significant differences in growth rates were detected between S. petersenii and S. americana. In all experiments, S. petersenii had the lowest growth rate. This ubiquitous species probably acts as a K-strategist. S. americana grew generally very quickly, especially at temperature 13 žC that is obviously optimal for it. Further, I observed a significant strain specificity, which is largely a well-known phenomenon in the ecophysiology. Significant differences in growth rates were noted between temperatures 13 žC and 16 žC, where all tested species grew best, as well. This is in accordance with a general recognition of...
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Comparative anatomy of genus Lasiocephalus - from tropical mountain forest to páramo
Ježková, Barbora ; Soukup, Aleš (advisor) ; Lhotáková, Zuzana (referee)
South American genus Lasiocephalus colonized high altitudes of the tropical Andes, the so called páramo, from lower elevations of the Andean forest. Páramo is a specific high-altitude environment characterised by pronounced diurnal changes in temperature, growing season over the entire year, low average temperatures, generally high humidity, and intense solar radiation. These specific environmental conditions are reflected by anatomical characters of the species. Given the known phylogeny of the group it was possible to observe anatomical adaptations along steep gradient of environmental conditions from forest to páramo. The hypothesis about adaptive changes that occurred during the colonization of the páramo habitats was confirmed. Observed characteristics were, for example, leaf area and thickness, epidermal cells cuticle and cell wall thickness, epidermal cells lumen height, ratio of palisade and spongy parenchyma, stomatal area, stomata length and width, stomata pore length and sieve elements average area. Results suggest that the anatomy of the plants reflect the environmental conditions of the habitats rather than the species phylogeny.
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Sister broods in the spruce bark beetle, \kur{Ips typographus} (L.)
DAVÍDKOVÁ, Markéta
The aim of this thesis was to elucidate the establishment of sister broods in the spruce bark beetle, Ips typographus (L.), at three localities of different elevation in Sumava Mountains. Fecundity, sex ratio in the offspring, regeneration feeding, development of reproductive organs, re-emergence rate and other ecophysiological topics were studied as well.
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Ecophysiological characteristics of key members of Betaproteobacteria in freshwater bacterioplankton
KASALICKÝ, Vojtěch
This thesis primarily focuses on one segment of freshwater Betaproteobacteria, the Limnohabitans genus (including the RBT lineage). As opposed to other recent research directions, the major aim was to recover the members of the previously uncultured RBT lineage through their isolation from various freshwater habitats. However, the results presented in this thesis have also ambitions to go far beyond the taxonomic descriptions only; the dissertation intends to contribute significantly to unveiling of important ecophysiological characteristics of the studied lineage in a set of both laboratory and field research. Therefore, understanding of growth characteristics, mortality, diversity and life strategies of aquatic microbes is of highest importance regarding profound human impact on water quality and increasing need of drinking water supplies.
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