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Epiphytic species of Lecanora subfusca group in the Czech Republic
Malíček, Jiří ; Vondrák, Jan (referee) ; Palice, Zdeněk (advisor)
The main aim of this bachelor work is to summarize knowledges on species of the Lecanora subfusca group growing in the Czech Republic, eventually taxa their occurence may be expected in our area. Only epiphytic and/or epixylic species are included in this study because of a large diversity of the group. Ten taxa have been published from the country. This group is poorly explored in Central Europe because of difficult determination of single species. A comprehensive treatment is lacking in this area. For most taxa of this group only limited information on ecology, distribution, chemistry and taxonomic concepts exists. The present work is reviewing up-to-date knowledge of this group. Historical sources were based mainly on morphological and anatomical data. These were evaluated and excerpted. The bachelor work should serve as a basement for the following diploma thesis.
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Specificity of insect-plant associations and their role in the formation of plant defenses and speciation
VOLF, Martin
The aim of this dissertation is to investigate what role insect-plant interactions play in the formation of host-plant defenses and in the diversification of both groups. We show that various groups of herbivore respond differently to host-plant defenses. Therefore plant defenses diversify into suites of complementary traits, as individual traits fail to provide protection against specialized herbivores. Further, we identify what levels of host-phylogeny shape the food-web structure of insect herbivores. We show that specialized herbivores are affected mainly by the terminal parts of the host-phylogeny. In contrast, more polyphagous guilds are affected mainly by the mid-levels of the host phylogeny because the effects of terminal or deeper phylogeny seem to be surpassed by other factors in more generalist insect species. In the last chapter, we show how specialized insect-plant interactions generated by tight insect-plant coevolution can influence the speciation in plants over environmental gradients.
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Biological study of hemp activity
HELLEROVÁ, Šárka
The aim of my study is to evaluate the impact of seed density on yields of hemp, which was cultivated in two areas, and subsequently to assess biological efficiency of infusion from hemp on fibroblastoidal line of mammalian cells L292. Afterthat in the case of above mentioned biological test we want to find out, if the density and different parts of plant will have an impact on efficiency of extract.
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Cytotoxic effect of some cyanobacterial crude extracts and metabolites against selected human cancer lines, especially focusing on pancreatic cancer cell line PaTu
VICKOVÁ, Kateřina
Cancer is disease that affects human population for many thousands of years. Fortunately fighting cancer is more and more effective. This is mainly thanks to combining different strategies of therapy and progress in novel drug development and research. Cyanobacteria are emerging as an important source of novel bioactive secondary metabolites which provides an opportunity for new drug discovery. The aim of this study was evaluation of three cyanobacterial strains for in vitro cytotoxicity against human cancer cell lines, with special focus on pancreatic cancer cells. Crude extracts and chromatographic fractions were tested for their possible use (effectiveness) as selective cytotoxic and/or pro-apoptotic agents. Probably novel compound with anti-proliferative activity was found and isolated by HPLC-MS techniques.
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Anabaena - Phenotypic and genotypic diversity of planktonic strains in fishponds and reservoirs of the Czech Republic
ZAPOMĚLOVÁ, Eliška
Morphological diversity of 61 Anabaena populations of 13 morphospecies was described under the field conditions of Czech fishponds and reservoirs. Polyphasic approach was then applied in classification of 45 clonal strains isolated from those populations. Detailed morphological analyses were performed and partial 16S rRNA gene sequences were obtained for 33 of the strains, and secondary metabolite production was evaluated in 20 strains. Plasticity of morphological characteristics under varied conditions of light, temperature, nitrogen and phosphorus was studied in selected strains, as well as their temperature and light growth requirements. The results were then discussed with respect to the delimitation of single Anabaena morphospecies. A new genus Sphaerospermum was defined for the morphospecies Anabaena kisseleviana, A. reniformis and Aphanizomenon aphanizomenoides, whose phenotypic and genotypic features differed considerably from all other Anabaena morphospecies. Unique information was provided on the occurrence and distribution of A. reniformis and Aph. aphanizomenoides in the Czech Republic.
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Cytotoxicity of the filamentous cyanobacteria in relation to its ecology
TOMEK, Petr
The aims of this study was to screen a cytotoxic activity in 53 strains of the genera Nostoc and Anabaena and to compare occurence of active isolates within different ecological groups. Selected cytotoxic strains were subjected to HPLC/MS analysis to identify their extracts composition. Isolates with strong cytotoxic effect containing unknown substances were fractionated to obtain pure fraction of this compound. Finally, the selected strains toxicity dependence on time and concentration was evaluated.
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