National Repository of Grey Literature 4 records found  Search took 0.00 seconds. 
Population models of plant life-cycles and their modifications by diseases and herbivores
Kasner, Marek ; Koubek, Tomáš (advisor) ; Koupilová, Klára (referee)
Pathogens and herbivores are two important groups of organisms with predominantly negative impact on their plant hosts. Although relationships at the individual level are relatively well understood, the data acquired by those studies cannot be easily translated into effects on the population. Various types of population models, also used in the case of the interactions, give us valuable insight into population dynamics. This bachelor thesis at first describes mechanisms and effects of plant pathogens (with emphasis on pathosystems with anther smut Microbotryum violaceum) and herbivores at the individual and population level for the demonstration of diversity of the systems and to stress the discrepancy between the two hierarchical levels. Furthermore, matrix and integral projection models are introduced as invaluable tools for population dynamics projections and understanding the underlying results of the interactions on plant populations. These models use the entire plant life cycle and require long-term censuses of demographic data. The role of these models in plant-pathogen interactions seems heavily underappreciated, however, and thus there is only a small number of studies with their application. The thesis describes mechanisms of the models, modifications in specific life-cycles and their...
Influence of environment on distribution and coexistence of different diseases on a single plant species
Mráčková, Michaela ; Koubek, Tomáš (advisor) ; Koupilová, Klára (referee)
Most plant species host one or multiple pathogens. However, studies are mostly focused on simple pathosystems. These studies deal for example with the virulence of the pathogen, plant resistance or influence of the environment on the pathosystem. The occurrence of more pathogens in one plant species is taken into account only in a few studies. Most of those studies focus on the coinfection of multiple pathogens in one individual host, especially in the agriculture, so there is very little information about coexistence of more pathogens in wild plant population. This paper summarizes the general information about plant and pathogen interaction, focuses on environmental effects and finally focuses on occurrence of multiple pathogens on one plant species. From the studies it is clear, that both, abiotic (light, temperature, humidity, etc.) and biotic conditions (pollinators or pests as vectors etc.) have impact on host- pathogen interaction. During co-occurrence of multiple pathogens in one host plant, various interactions between coinfecting pathogens can occur (competition, cooperation, etc.). Resistance of plant to one pathogen can be affected by presence of other pathogens and stress factors. Finally, coinfection may also affect virulence of individual pathogens. Key words: plants, pathogens,...
Ecology of the pathosystem of anther smut on Dianthus carthusianorum
Koupilová, Klára ; Koubek, Tomáš (advisor) ; Dostál, Petr (referee)
Anther smuts (Microbotryum violaceum s.l.) represent a well-known system for studying pathogens of wild plants and coevolution between pathogens and hosts. Infected plants produce sterile flowers with anthers filled with fungal spores which are transmitted to other host plants by pollinators. Data from existing research come mainly from the genus Silene. However, the applicability of these findings to other host plants of anther smuts is largely unknown. Therefore, this thesis focuses on a different host species - Dianthus carthusianorum. First, the pattern of disease was surveyed in natural populations of D. carthusianorum in a small area in Střední Povltaví. Most populations were infected to various degrees and only a few populations remained completely healthy. The prevalence of disease was positively correlated with size and density of host populations. On the other hand, environmental factors and the degree of connectedness had very little effect on disease prevalence. Second, additional data were collected from a subset of populations to determine plant resistance and densities of pollinators. Differences in resistance among populations (as inferred from flower inoculations) were not significant. Populations differed in densities of pollinators, but there was no correlation between densities...
Ecology of flower smuts (Microbotryum) and their hosts from family Caryophyllaceae
Koupilová, Klára ; Koubek, Tomáš (advisor) ; Marková, Jaroslava (referee)
Anther-smut fungus (Microbotryum spp.) infecting plants of the Caryophyllaceae represents one of the most extensively studied plant pathogen systems. Anther-smut is a pollinator-borne disease that turns infected plants completely sterile. The aim of this thesis is to sum up the main findings about ecology and epidemiology of anther-smut disease and it mainly deals with various factors that influence disease spread and occurrence in nature. According to existing research, abiotic factors play minor role compared to biotic factors and interactions. Among the most pronounced, we can find variability in pathogen virulence and host resistance and also vector behaviour. When studying epidemiology of Microbotryum spp., it is necessary to take account of spatial population structure and metapopulation dynamics as well. Comparing life histories of different host species can also bring useful information. Key words: anther-smut, Microbotryum, Caryophyllaceae, pollinators, resistance, epidemiology, metapopulation dynamics.

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1 Koupilová, Kristýna
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