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Population differentiation of Ochrophytes
Mensová, Anna ; Jurdíková, Katarína (advisor) ; Kulichová, Jana (referee)
This bachelor thesis deals with a differentiation of populations of Ochrophytes (photosynthetic Stramenopiles). Natural populations can differ in many aspects and their differentiation is observed on several levels. Ecophysiological and morphological differences are very often caused by phenotypic plasticity, which is a flexible answer to changing conditions of habitats. Genetic differentiation could express an adaptation to the local environmental conditions. The adaptation and a long-term isolation of populations are considered to be the leading factors in genetic differentiation. The other factors contributing to genetic differentiation are random evolutionary events such as founder effect or genetic drift. Detailed studies of populations lead to uncover the factors that cause the differentiation of populations as well as they contribute to the understanding of speciation mechanisms. The thesis compiled the information about different types of variability among populations within the classes of Ochrophytes.
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Růst, genetické a morfologické charakteristiky různých populací okouna říčního (Perca fluviatilis) v intenzivní akvakultuře
GEBAUER, Tatyana
Zootechnical and behavioural traits can vary substantially among wild allopatric European perch populations. Choosing wild European perch population(s) showing higher growth rate, lower cannibalism and size heterogeneity with specific behavioural traits such as low aggressive interaction rate and homogeneous spatial distribution in rearing units are crucial for the establishment of the European perch broodstock and subsequent selective breeding programs. Therefore, knowledge of the zootechnical and behavioural traits relative to geographic origin supported by genetic analyses may ultimately help to overcome current challenges and bottlenecks of European perch aquaculture. Population differences in zootechnical and behavioural traits can be shaped by genetic differentiation, phenotypic plasticity, or by their combination. However, it is not clear whether the inter-population differences are genetically- or environmentally-induced. Therefore, we explored the zootechnical traits of geographically different European perch populations at larval- (two Finish, two Polish, two Slovakian, one Czech; Chapter II) and juvenile-stages (Polish, Czech, Slovakian; Chapter III) in the same standardized conditions reducing the environmental effect. Additionally, we provided a genetic-based assessment on four mitochondrial markers: cytochrome b, D-loop of control region, 16S rRNA, and cytochrome oxidase I (Chapters II, III). In Chapter IV, we observed behavioural traits of larvae and juveniles from two Finish and one French populations. According to obtained results, zootechnical and behavioural traits differed among allopatric populations of European perch. Moreover, the differences in zootechnical traits were mainly observed between most genetically differentiated populations (both Finish in Chapter II, and Polish in Chapter III). This could suggest a genetic basis of the observed growth differentiation and, consequently, a potential heritability of this pattern. Additionally, higher growth rate of northern populations could be partly attributed to behavioural traits as we found more cohesive and homogenous group structure in both Finish compared to French populations which, on the other hand, showed higher aggressive interactions. However, European perch larvae and juveniles from genetically lower- or un-differentiated populations (i.e. Polish, Slovakian and Czech in Chapter II and Slovakian and Czech in Chapter III) showed variations in zootechnical traits as well. The variation could be a consequence of different food intake, health status, pre-collection environment, transgenerational effect and usage of conservative mitochondrial markers, i.e. the lack of genetic differentiation among some populations should be further assessed by higher resolution analyses (e.g. microsatellites). Further studies are needed to assess the importance of these factors in geographic differentiation of aquaculture performance.
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Role of phenotypic plasticity, genetic and epigenetic differentiation in ecophysiological traits of Festuca rubra L. in response to climate change
Koláříková, Veronika ; Münzbergová, Zuzana (advisor) ; Schnablová, Renata (referee)
Understanding the ability of species to respond to climate change is essential for prediction of their future distribution. When migration is not adequate, reaction via phenotypic plasticity and/or genetic/epigenetic adaptation is necessary. The main aim of this study is to determine mechanisms of response to climate change in dominant grass species Festuca rubra. The study used reciprocal transplant experiment with growth chambers simulating different climatic conditions. Original localities in western Norway represent factorially crossed gradients of temperatures and precipitations, thus it was possible to study the effect of temperature and moisture separately as well as combined. In first part of the experiment, plastic responses were separated from genetic differentiation. To do this, plants with different genotypes from original localities were transplanted to growth chambers set to simulating temperature and moisture course in the four extreme localities (wettest and driest combined with warmest and coldest). After five months, ecophysiological photosynthetic-related traits were measured. These traits are important for species ability to adapt and maintain high fitness and thus they are essential for plants function. Specifically, it was net photosynthetic rate (PN), fluorescence of...
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Population differentiation of Ochrophytes
Mensová, Anna ; Jurdíková, Katarína (advisor) ; Kulichová, Jana (referee)
This bachelor thesis deals with a differentiation of populations of Ochrophytes (photosynthetic Stramenopiles). Natural populations can differ in many aspects and their differentiation is observed on several levels. Ecophysiological and morphological differences are very often caused by phenotypic plasticity, which is a flexible answer to changing conditions of habitats. Genetic differentiation could express an adaptation to the local environmental conditions. The adaptation and a long-term isolation of populations are considered to be the leading factors in genetic differentiation. The other factors contributing to genetic differentiation are random evolutionary events such as founder effect or genetic drift. Detailed studies of populations lead to uncover the factors that cause the differentiation of populations as well as they contribute to the understanding of speciation mechanisms. The thesis compiled the information about different types of variability among populations within the classes of Ochrophytes.
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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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