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Functions of secondary metabolites of lichens
Zvěřinová, Gabriela ; Svoboda, David (advisor) ; Bouda, František (referee)
This bachelor thesis is a review of available literature about lichen secondary metabolites and their functions. Lichens produce a great variety of these compounds; most of them are unique to the lichen symbiosis and are not found in higher plants. Besides the role of these compounds in chemotaxonomy and systematics, lichen secondary metabolites exhibit various biological functions and can affect biotic and abiotic interactions of lichens with their environment. Well-known and often described functions of lichen substances include especially antimicrobial, antiherbivory and antioxidant activity, allelopathy, metal homeostasis and photoprotection. This thesis is focused on these functions and summarizes current knowledge in this area. Key words: lichen, secondary metabolites, allelopathy, antimicrobial activity, herbivory, antioxidant activity, photoprotection, metal homeostasis, pollution tolerance, literary review
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Secondary metabolites, allelopathy and their significance in the invasion of Heracleum mantegazzianum
Jandová, Kateřina ; Dostál, Petr (advisor) ; Frouz, Jan (referee) ; Valterová, Irena (referee)
One theory concerning the invasiveness of exotic plants suggests that they exude allelopathic compounds that are novel in areas being invaded. Here, I tested for allelopathic effects of root exudates of the invasive plant Heracleum mantegazzianum (giant hogweed) in a series of experiments both in vitro and in the garden, and compared them with effects of its native congener H. sphondylium (common hogweed) and two less related native species. Moreover, I addressed intraspecific variability of allelopathy by comparing effects of 41 different maternal lines of H. mantegazzianum sampled from several areas and populations within the Czech Republic. Not only the effects, but also the identity of allelopathic compounds was investigated. In order to test also for the interaction of allelochemicals with soil microorganisms, I analysed the composition of soil microbial communities expressed as phospholipid and neutral lipid fatty acids (PLFA and NLFA, respectively) together with nutrient conditions and light availability at invaded sites in the Czech Republic. The results show that H. mantegazzianum is able to exert phytotoxic effects in vitro as well as in the garden experiment; however, its effects did not differ from the inhibition caused by the native species tested. Variation partitioning among areas,...
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Plant competition in the early ontogeny
Čiháková, Klára ; Weiser, Martin (advisor) ; Fendrych, Matyáš (referee)
Competitive impacts on early stages of plant ontogeny are being reviewed in this thesis. Those processes select for evolutionary or phenotypically plastic responses in timing of emergence, seed morphological properties, maternal effects and reaction on environmental cues. However, pattern of the strong selective pressure is sometimes not apparent, due to the lack of data and knowledge on the influence of the other factors in plant's life.
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Plant-soil interactions in succession on post-mining sites
MUDRÁK, Ondřej
Field observation and manipulative experiments were carried out to describe and test important processes affecting the plant succession on Sokolov post-mining sites. Examined was mainly effect of dominant tree species (which are planted or spontaneously established) on understory plants, litter decomposability and effect of earthworms (Lumbricidae) on late successional plant species.
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Ecological study of invasive species \kur{Lupinus polyphyllus}
HURTOVÁ, Jaroslava
Species Lupinus polyphyllus is one of the most hazardous invasive species in the Czech Republic and its increasing occurence represents a threat of native biodiversity not only in the flora of conservation areas. Influence of management experiments on invaded communities was studied on permanent plots founded on three localities in the Šumava National Park. The role of nitrogen fixed in this invasion was explored by analyzing of soil samples. Influence of allelopathic inhibition of invasive species on some coexisting native species was tested in the laboratory experiment.
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Production and alleopathic potential of plants of Satureja genus
HOŘEJŠÍ, Lenka
In Czech Republic, two species of savory namely summer savory (Satureja hortensis L.) and winter savory (Satureja montana L.) are grown. Aim of this work is to summarize information about biological characteristics and requirements of both species on environmental conditions, production of these drugs in the Czech Republic and abroad, effective substances and their effects and possibilities of savory utilization in manufacturing industry and agriculture. Overground parts and leaves of savory plants are exploited like a spice or a drug that positively influences digestion, reduces flatulence and has also anti?inflammatory effects. Major components of volatile oil savory are phenolic compounds carvacrol and thymol. Just carvacrol and thymol are considered as allelopathic compounds of mint, sweet basil, caraway and others. On the basis some studies, we can assume that they are also potential allelopathic compounds of savory. Summer savory is more suitable for growing in the Czech Republic especially in the ecological agriculture than winter savory. We can easily include this crop in the crop rotation because it is an annual plant and there is a lower hazard of failure e.g. frost damage. Growing of winter savory would be more suitable for the essential oil production.
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Study of allelopathic effects in species of Impatiens genus (Impatiens L.)
KREJČOVÁ, Jana
All three jewelweeds species (Impatiens. L.)contain series of secondary metabolites from category of phenolic substances, e.g. naphthoquinones. This substances belong to allelochemicals, they can to affect germinability and growth of other plants. The extracts from jewelweeds (leaves, roots) and their fractions can to affect negatively germinability and growth of the chosen weed's seeds. Knowledges of allelopathic effects in jewelweeds species on other plants might be of important impact on ecological farming in the implementing of alternative herbicides.
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