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Dissemination of Cordyceps fumosorosea by entomopathogenic Nematodes
HOPFGARTNER, Miriam
C. fumosorosea is an entomopathogenic fungus that has been used as a biocontrol agent against various insect hosts for some time. Its efficacy as an entomopathogen can be increased by joined application of the fungus with entomopathogenic nematodes. The aims of this thesis are to investigate the impact of the foraging strategy of different nematode species on the spore dispersal of C. fumosorosea and the significance the nematode's 2nd stage cuticle holds for spore dissemination. Additionally, novel approaches for the enhancement of spore transmission in soil environments via adhesives are explored.
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Využití biologických prostředků na ochranu brambor vůči mandelince bramborové
KURÁŽ, Jakub
The aim of the work was to verify possibilities of biological control against Colorado potato beetle by using cultivated indigenous entomopathogenic fungi and entomopathogenic nematodes from potato fields in Czech Republic before chemical treatment or ecological agriculture and verify their efficacy against Colorado potato beetle. All results are included in attached charts or tables.
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Influence of metabolites of entomopathogenic bacteria genus \kur{Xenorhabdus} on the survival and reproduction of facultative entomoparasitic and phytophagous nematodes
JAKUBÍKOVÁ, Hedvika
Bacteria of the genus Xenorhabdus live as the natural symbionts of the entomopathogenic nematodes of the family Steinernematidae. They produce a wide range of toxic secondary metabolites of different chemical structure and effect. The synthesis of particular products is specific for each strain of Xenorhabdus. The thesis is focused on evaluating the impact of bacterial metabolites on facultatively entomoparasitic nematodes Oscheius myriophila, the free-living nematode Caenorhabditis elegans and the phytophagous potato cyst nematode Globodera rostochiensis. Target species of nematodes were exposed to 37 strains of Xenorhabdus bacteria, isolated from various species of Steinernematidae. Testing the impact of bacterial metabolites on O. myriophila and C. elegans nematodes was performed both by direct cultivation of target species on solid medium with live bacterial cultures as well as in sterilized liquid bacteria cultures. The effect of toxic substances on G. rostochiensis was evaluated only in selected sterilized bacteria cultures.
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Změny v produkci adipokinetických hormonů u \kur{Pyrrhocoris apterus} v různých částech CNS po působení stresových faktorů
VÁVRA, Jakub
The main goal of this bachelor thesis was to characterize changes of adipokinetic hormone (AKH) production in the brain and corpora cardiaca of the firebug Pyrrhocoris apterus during the infection caused by entomopathogenic nematode Steinernema carpocapsae. The effects of the pathogen were investigated by determination of AKH level in the CNS using competitive ELISA test and immunohistochemical localization with a specific antibody against the P. apterus AKH (Pyrap-AKH). The results confirmed presence of majority of AKH in corpora cardiaca and smaller amount also in brain. The infection increased AKH production in both monitored organs, however, in brain the elevation was more intensive than that in corpora cardiaca.
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Characterisctics of the mitochondrial genome of the roundworm Oscheius myriophila (Rhabditidae)
PECHOVÁ, Hana
Genus Oscheius represents specific group of nematodes which are facultatively entomopathogenic, i.e. they occur in transient stage between necromenic and parasitic life style. Therefore, it represents an interesting model for evolutionary studies; however, the taxonomy of the genus is still not clear. Analysis of the full mitogenome of Oscheius myriophila may help to enhance our knowledge on the selected nematode species with respect to the taxonomy, phylogeny as well as its biology in general.
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Multilokusová charakteristika symbiontů entomopatogenních hlístovek rodu \kur{Steinernema}
FAKTOROVÁ, Lucie
During the evolution some groups of organisms have become coevolutionary associated with other groups, as is the case of host symbiont systems. To explore coevolutionary history of hosts and their associated symbionts, phylogenetic reconstruction of symbionts and phylogenetic reconstruction of hosts are usually compared. Coevolution is described by coevolutionary events (cospeciation, host switch, duplication, failure to diverge events and linage sorting events). The aim of this work was to test the suitability of MLST method for the complex of entomopathogenic nematodes from the genus Steinernema (with detailed analysis of Steinernema feltiae) and their symbiotic bacteria Xenorhabdus bovienii and subsequently use cophylogenetic comparative analysis to determine their level of cospeciation.
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Nucleotide variability in \kur{enol-1} gene of entomopathogenic nematodes \kur{Heterorhabditis bacteriophora} and \kur{Steinernema feltiae}
HEJNÍČKOVÁ, Martina
The topic of this bachelor thesis is enol-1, parasitism-related gene in entomopathogenic nematodes. First part of this thesis deals with pattern of the enol-1 nucleotide variability. Nucleotide sequence of enol-1 was obtained from 9 strains of Heterorhabditis bacteriophora and 8 strains of Steinernema feltiae. I characterised and compared its structure and nucleotide variability. Phylogenetic analysis of enol-1 was done with closely related nematode coding sequences, acquired from internet databases. The second part of this thesis is devoted to virulence testing. Larvae of Galleria mellonella were infected with different strains of entomopathogenic nematodes, and their mortality was summarized.
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The Influence of Pesticides on the Infectivity of Entomopathogenic Nematodes
NERMUŤ, Jiří
It is known that entomopathogenic nematodes rarely live in fields where pesticides and fertilizers are used. Because they are organisms with a high potential for biological and integrated pest control the thesis tried to determine the influence of pesticides on the infectivity and mortality of selected nematodes: Steinernema feltiae, S. arenarium and S. kraussei in water solution of some pesticides. The results are that preparations Vydate (a. i. oxamyl) and Sulka (a. i. sulphur) have the highest negative influence on both characteristics. These pesticides cause a mortality of 94.3 - 99.9 % and reduce infectivity by about 50 {--} 75 % (level 3). The following preparations may be identified as having higher potential for infectivity reduction: above all, Starane 250 EC (fluroxypyr), Sumithion super (fenithrothion), and Novozir MN 80 (mancozeb); on the other hand, Treflan 48 EC (trifluralin) significantly increases mortality. Another important observation is a fact that infectivity is significantly influenced only by concentration of pesticides, not by exposure time. During an experiment with enhacement of resistance to oxamyl (Vydate) I falling mortality and increasing infectivity of entomopathogenic nematodes were observed after five rounds.
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Synergism of entomopathogenic nematodes and entomopathogenic fungi
ŠILLEROVÁ, Tereza
The potential synergism between chosen species of entomopathogenic nematodes (Steinernema arenarium, Steinernema feltiae) and entomopathogenic fungi (Beauveria bassiana, Isaria fumosorosea, Lecanicillium lecanii) is investigated in this study. It is theoretically possible to expect increasing of their efficiency at the collective introduction into environment. Creating of uniform laboratory method which will be possible to use at the research of this interaction system is a part of this study.
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