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Natural epigenetic variation: a driver for adaptation of wild plant populations?
Sammarco, Iris ; Latzel, Vít (advisor) ; Johannes, Frank (referee) ; Pečinka, Aleš (referee)
A growing body of literature suggests that epigenetic variation might contribute to local adaptation of natural plant populations. Epigenetic mechanisms, such as DNA methylation, can in fact quickly alter phenotypes in response to environmental changes. Furthermore, these changes can be inherited across several generations (especially clonal), suggesting that DNA methylation may enable heritable phenotypic variation and eventually contribute to adaptation. However, it is still unclear whether epigenetic mechanisms can have an adaptive potential in plants, or in other words, whether they present variation among natural populations, are inherited across generations and have fitness effects. During my PhD project, together with my co-authors, I tested these conditions on several natural populations of two non-model clonal plant species, the wild strawberry (Fragaria vesca) and the black poplar (Populus nigra). To do so, I used the current gold standard for DNA methylation analysis (Whole Genome Bisulfite Sequencing), which allowed me to characterize the genome-wide DNA methylation level of individual plants at the single base-resolution. For both species, I found extensive DNA methylation diversity among populations, which was partially affected by the natural climatic conditions of the populations...
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Effect of pathogens on clonal plants
Koděra, Ondřej ; Koubek, Tomáš (advisor) ; Duchoslavová, Jana (referee)
1 Abstract: More than half of Central Europe's plant species are capable of propagating vegetatively via clonal growth, many of them identifiable as some of the most common species. Clonal ecology has been studied mainly due to its positive influence on plant fitness; Less attention, however, has been dedicated to the cost of clonal growth which is directly connected to the pathogen's inner plant invasion and transmission. The existence of clonal growth enables both partners in the plant-pathogen interaction to create new life strategies differing from those created by infected nonclonal plants. Pathogens that infect plants with a strong lateral spread were selected for higher aggressivity in evolution. In turn, their effect is negative on survival, the creation of new ramets and also on the whole growth and development of the host. If the development of the clonal growth organs becomes faster than the growth of fungal hyphae, the ramets can escape the infection passively. The influence on the host is not only negative as the infected plant can perform stimulated clonal growth or compete with healthy plants to a more successful extent. The aims of this thesis are: to search and summarize all the available information concerning this specific plant-pathogen interaction; to discuss the unanswered questions...
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Integration of clonal plants in heterogeneous environment
Vinšová, Jana ; Weiser, Martin (advisor) ; Macek, Petr (referee)
Clonal plants may be able to cope with spatial and temporal heterogeneity due to the physiological integration of ramets. To begin with, I discuss basic characteristics of clonal plants and then I provide a review of theoretical and empirical work dealing with the advantages and disadvantages of clonal growth in heterogenous conditions. Three main traits - translocation of resources, division of labour and foraging - are examined in terms of their contribution to the success of clonal plants. Despite a large amount of attention which this topic has received in the past few decades, a number of issues still remain unclear.
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Habitat dependence of persistence of clonal connection in plants
Martincová, Nina ; Weiser, Martin (advisor) ; Koubek, Tomáš (referee)
The review is about the role of environment to the longevity of connection in clonal plants. The first part is dealing with theoretical models, which describe the interaction of plants with different strategies in longevity of clonal connection in a model habitat. Subsequently, it analyses concrete attributes of the environment - heterogeneity, carrying capacity, amount of disturbances and competition. This part focuses more thoroughly on their impact on persistence of clonal connection and strategy of clonal reproduction in general. The last part refers to some other phenomena which could influence the length of persistence of a clonal connection.
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Importance of epigenetic variability in evolution of clonal plants
Mareš, Štěpán ; Pinc, Jan (advisor) ; Latzel, Vít (referee)
Because of their low genetic variability and limited ability to respond to the changing environment, clonal plants are often considered an evolutionary dead end. On the other hand, numerous recent studies showed that clonal plants can react to the changing environment through epigenetic mechanisms, especially through DNA methylation. Moreover, epigenetic information in clonal plants can be transferred to future generations (so-called transgenerational memory). As a result, epigenetics can ensure better fitness of the next clonal generation. The aim of this work is to summarize the knowledge about the role of epigenetic variability in the life of clonal plants performing limited genetic variability. Key words: epigenetics, DNA methylation, epigenetics variation, clonal plants, transgeneration memory
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Ecological determinants of plant clonal growth
Martincová, Nina ; Weiser, Martin (advisor) ; Latzel, Vít (referee)
The aim of this study is to provide a further insight into influence of environment on clonal plants. The study focuses particularly on effects of fertilization level and light availability on production and growth of clonal organs. Three experiments were carried out within the study, targeted to elicit influence of these environmental conditions or clonal interactions on six species of clonal plants. Interspecies dependencies on these conditions was compared, regarding habitat occurrence of these species. A comparison was made also between species producing rhizomes and stolons. The experiments revealed that five of six studied species show significant relationship among at least one environmental condition and parameters of clonal reproduction. Most of the species showed higher elongation and production of clonal organs in relation to fertilization level. On the contrary, only three species reacted significantly to the light availability level by alternation of at least one parameter of clonal reproduction and the light availability level affected each species differently. A strong influence on production and elongation of clonal organs had also a size of a plant. There was not found significant difference in influence of environmental conditions on clonal reproduction among plant families. It...
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Habitat dependence of persistence of clonal connection in plants
Martincová, Nina ; Weiser, Martin (advisor) ; Koubek, Tomáš (referee)
The review is about the role of environment to the longevity of connection in clonal plants. The first part is dealing with theoretical models, which describe the interaction of plants with different strategies in longevity of clonal connection in a model habitat. Subsequently, it analyses concrete attributes of the environment - heterogeneity, carrying capacity, amount of disturbances and competition. This part focuses more thoroughly on their impact on persistence of clonal connection and strategy of clonal reproduction in general. The last part refers to some other phenomena which could influence the length of persistence of a clonal connection.
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Clonal integration of Agrostis stolonifera in heterogeneous soil environment
Duchoslavová, Jana ; Weiser, Martin (advisor) ; Klimešová, Jitka (referee)
Clonal plants may be able to cope with spatial heterogeneity due to the physiological integration of ramets. Previous studies demonstrated that benefits of clonal integration increase with patch contrast between individual ramets. However, the same magnitude of contrast may be perceived differently in rich and poor environments. According to the theoretical work of Caraco and Kelly (1991), I expected these benefits to be the greatest in overall poor conditions and high between-patch contrast. To test this hypothesis, I conducted experiments with pairs of ramets of a stoloniferous grass, Agrostis stolonifera, grown in variously nutrient rich conditions. The experiment with pairs of ramet of similar developmental age showed only very weak effect of integration on growth of ramets, although integration significantly improved survival of ramets and also affected root-shoot ratio of ramets. Nevertheless, there were considerable benefits of integration in the experiment with developmentally older mother ramets and their daughter ramets. Contrary to the predictions, the benefits of integration were bigger in rich conditions and they decreased with increasing between-patch contrast. In addition, effect of integration on root-shoot ratio of ramets was opposite to the expected specialization for acquisition...
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Populační biologie rostlin napadených systémovými parazity
Koubek, Tomáš ; Herben, Tomáš (advisor) ; Šmilauer, Petr (referee) ; Wennström, Anders (referee)
Three separate studies of the effect of plant pathogen on population biology of its host are presented in the thesis. Two are using field data about a widespread system of plant Falcaria vulgaris and its systemic rust fungus Puccinia sii-falcariae. The first study shows, that the disease prevalences in 40 populations of the plant were correlated with the moisture, the soil reaction and the cover of the herb layer at the localities. This was probably a result of the interaction of the life history of the plant and different effect the disease has at various localities. Similar pattern was found in the second study that aimed to determine long-term effect of the disease at the population level at four chosen localities over 4-5 years. Population growth rates were only rarely predicted to be higher for the healthy part of the population when compared with the whole population. Other analyses have however found big differences among years and localities. The locality type (slope vs. field populations) was important factor influencing population stage composition and importance of life cycle transitions for the growth of the population. Finally, the last study explores the possibility that systemic infection in clonal plants might be able to select against clonality. The result of the modelling showed that more...
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