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Evolutionary significance of visual traits of flowers and their influence on the pollinator constancy
Haveldová, Alice ; Štenc, Jakub (advisor) ; Klečka, Jan (referee)
Flower constancy is a behavior in which the pollinator visits flowers of the same plant species in a sequence more than would correspond to its preference for the given plant. This behavior is advantageous for plants because it can ensure efficient intraspecific pollen transfer which has a positive effect on their biological fitness. More efficient pollen transfer can lead to the selection of (visual and olfactory) flower traits that encourage flower constancy of pollinators. The main visual floral traits that affect constancy include colour, pattern, shape and size. However, these traits are of different importance for pollinators when they are deciding which flower to visit, and therefore their effect on flower constancy varies. The degree of flower constancy also differs between the functional groups of pollinators. Flower constancy is generally low in vertebrates, but insects and especially representatives of the order Hymenoptera are often flower constant.
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The importance of the arrangement of flowers in the inflorescence on the plant reproductive success
Chvojková, Karolína ; Štenc, Jakub (advisor) ; Sklenář, Petr (referee)
Inflorescence and its properties have a fundamental influence on the pollinating behavior of pollinators, which can affect the resulting reproductive success of plants. Clustering of more flowers in the inflorescence is an advantage for plants due to the diversification of pollen sources and greater visual supply, which can attract more pollinators and thus increase the chance of pollen transfer to other individuals and ensure genetic variability of the offspring. The disadvantage of multiple flowers in one inflorescence may be both an increase in energy requirements for the formation and maintenance of multiple flowers and an increased risk of geitonogamy. Plants prevent geitonogamy within the inflorescence by various adaptations. The aim of this work is to evaluate the effect of inflorescence arrangement on successful plant reproduction. When studying the arrangement of flowers in the inflorescence, it is necessary to take into count not only their morphology, i.e. the shape, number, size and arrangement of flowers, but also other functional properties in the form of genitals, sterility and rewards. The resulting effect of flower arrangement on the reproductive success of plants also depends on the vectors that transfer pollen, in this case especially insect pollinators, which are affected by...
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Pollinator pollen carryover effectiveness and plants' ability to enhance it
Freudenfeld, Martin ; Janovský, Zdeněk (advisor) ; Mikát, Michael (referee)
Pollinators carry over pollen from one flower to another. They facilitate plant reproduction. Pollinator functional groups differ in their effectiveness of pollen carryover. Quantity of pollen grains on their body and deposition on stigma are very important. Pollinator carryover capacity depends on its functional traits. Body size, hairiness, visitation behaviour, foraging preferences, flower constancy and abundance of pollinators are significant. Plants can enhance effectiveness of their pollination by adaptations to specific pollinator functional groups. They improve positioning of pollen on pollinators by specific changes to floral morphology, quantity and size of pollen grains. They can also enhance the effectiveness through aggregation of pollen grains into groups or into pollinia or by optimisation of pollen release in time.
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Pollination in forest ecosystems
Veljačiková, Hana ; Janovský, Zdeněk (advisor) ; Hadrava, Jiří (referee)
Interactions between plants and their pollinators in temperate forest are different from open habitats. In forest, pollinators are less abundant and this results in frequent pollen limitation of forest understory herbs. Pollinators also need to be adapted for flying in complex stands and for living in unfavorable microclimatic conditions. Floral resources predominantly limit pollinator abundance because of their uneven distribution in space and time. In the present bachelor thesis, I summarize knowledge on pollinator conservation and phenology as well as food resources, microclimate, which together with sufficient nesting options seem to contribute the most to pollinator abundance. Type of forest management is also an important factor, which affects density and diversity of pollinators. Generally, thinning out of trees and removal of understory shrubs have positive effect on flower abundance and benefit pollinators. Factors that influence reproduction success of flowers and pollen transfer distances are further discussed.
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Pollinators as a subject of science education in lower secondary school
MAŠKOVÁ, Anna
This bachelor thesis is focused on pollinators as a subject of science education in lower secondary school. It includes survey of pollination, pollination syndromes and importance od the groups of insects involved in pollination. Comparative analysis of biology textbooks for lower secondary schools in terms of pollinators, pollination and results of questionnaire survey of student's knowledge on this topic. Based on this knowledge was designed a time - saving project to teach pollinators.
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Geometric morphometrics of shape and symmetry of flower structures - ecological and evolutionary significance
Rubešová, Veronika ; Neustupa, Jiří (advisor) ; Woodard, Kateřina (referee)
I did a research of relevant literature on geometric morphometrics, its usage for a study of floral symmetry, and ecological and evolutionary significance of floral symmetry in general. Description and application of morphometric methods is included in the first part of the thesis. Then, the main types of floral symmetries are described and illustrated. Morphometric studies on several model floral lineages are discussed in subsequent parts of this bachelor thesis. Many of the studies are made on some species of family Brassicaceae. Modern morphometric methods and perspectives of their application in floral research are presented in the last chapter.
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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...
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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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Diversity of bees on selected crops and their contamination by pesticides
HÝBL, Marian
Measurement of diversity and chemical contamination of bees took place at two locations. At the Zborov site, conventionally growing rape and Malonty, where it is managed in an ecological regime. At the Zborov locality, 81 individuals from 3 families, including 20 species, were captured. In addition, analyzes have confirmed the presence of pesticides in bees. In contrast, 229 individuals from 5 families, including 36 rings, were seized at Malonty. Analysis of bees in this area has rebutted the presence of pesticides.
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Beginning and duration of flowering period in selected arable weed species
Trefil, Daniel ; Holec, Josef (advisor) ; Václav, Václav (referee)
Arable weeds are usually perceived as harmfull organisms in crops. On the other hand, the weeds provide a stable source of food for insects and other invertabrates that feed on pollen and nectar. Majority of crops are not able to provide long-term food component for invertebrates because their flowering is synchronized. Arable weeds flower continously throughout the growing season. There is possible to find many flowering species for the whole year.
The main aim of the study was to determine the onset and duration time of flowering period for selected arable weed species. The observation was conducted at the Demonstration and experimental field of Faculty of Agrobiology, Food and Natural Resources neighbouring areas as well as demonstration plots with rare weed species that do not occur in fields naturally. Inventory of flowering species was performed weakly from 9th calendar week (after frost period) and finished at 48th calendar week. There were found and evaluated 160 plant species of which 67 were the rare species from demonstration plots.
First flowering weeds were photoperiodically neutral species, mainly from the group of winter annual weeds followed by ephemeral annual weeds. Among others, the late-flowering species were particulary from the group of summer annual weeds, but also some from perennial species.
During the first week of observation, 11 flowering species were found. The number gradually increased up to a maximum of 118 flowering species in the 27th calendar week; then the number of flowering plant species naturally decreased. Newly flowering species were being found until 36th calendar week. Weed differed significantly in onset of the flowering acording to perenniality, in most cases. Length of flowering period in individual species was in relation to particular families.
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