|
|
Účinnost mykoparazitických a entomopatogenních hub proti houbovým původcům onemocnění rostlin
SINKALA, Natasha
Entomopathogenic and mycoparasitic fungi have the potential to be used both locally and internationally as an effective and environmentally friendly strategy for the man-agement of pests and plant diseases caused by fungal pathogens. In this bachelor thesis, the efficacy of beneficial fungi was tested under laboratory conditions. The methodology involved isolation and description of useful fungal species and subse-quent testing of useful fungi with potential mycoparasitic and antagonistic effects. The efficacy of the fungi was tested on pathogens that were mainly isolated from seeds or diseased legume plants. The experiments revealed that all Trichoderma strains isolated from soil of the Czech Republic showed mycoparasitic effect on se-lected pathogens. However, the efficacy of the strains depended on the type of fun-gal pathogen. Spore production of Trichoderma strains was also evaluated both in the control variant as well as the mutual interactions with pathogens. The results again showed differences in spore production among the Trichoderma strains. The myco-parasitic effect of the entomopathogenic fungi Isaria fumosorosea and Akanthomyces attenuatus against the pathogen Botrytis cinerea was also evaluated. The results re-vealed that although I. fumosorosea and A. attenuatus showed a significant mycopar-asitic effect against Botrytis cinerea, the mycoparasitic fungus T. virens showed the highest efficacy against the pathogen. The findings indicated that both mycoparasitic and entomopathogenic fungi are sustainable alternatives to artificial pesticides in the fight against fungal agents of plant diseases.
|
|
|
Effect of the entomopathogenic fungus Isaria fumosorosea on physiological processes in insects
GAUTAM, Umesh Kumar
The project is focused on a study of the infection elicited by entomopathogenic fungus (EPF) Isaria fumosorosea in two model species - the firebug Pyrrhocoris apterus and cockroach Periplaneta americana - and a role of adipokinetic hormones (AKHs) during that. The AKHs are neuropeptides that belong to the AKH/RPCH family and are known mainly for the mobilisation of energy reserves. The AKH role during the fungal infection was monitored by determination of mortality, gene expression in CNS, level of anti-oxidative stress markers, general metabolism, level of nutrients and activity of digestive enzymes. The I. fumosorosea infection elicited severe stress in the infected insects as documented by increase of the AKH expression and AKH levels in CNS of both insect models. The mortality test showed that application of AKH increased the efficacy of EPF application. It is supposed that AKH stimulated higher turnover of fungal toxins by enhanced intensity of metabolism (documented by higher carbon dioxide production) and encouraged the fungus growth by enrichment of haemolymph (a medium for the fungus) by mobilised nutrients. Interestingly, I. fumosorosea affected also digestive processes with substantial inhibition in midgut and partial inhibition in the caeca of male cockroach's digestive enzymes. Another part of this work was to examine changes of the vitellogenin (Vg) level in P. apterus after the I. fumosorosea treatment. The infection significantly reduced the Vg transcript level (checked by quantitative real-time PCR) in the female fat body and protein level in haemolymph (checked polyacrylamide gel electrophoresis). Interestingly, in the male fat body, Vg transcript level significantly increased after the infection, but EPF did not change protein level of male hemolymph. The obtained results point to an interesting role of Vg in insect defence reactions against EPF and are a good example of a trade-off between the Vg function in reproduction and defence reaction. Results of the project might be useful for better understanding of the mechanism of action of entomopathogenic fungi versus AKH, and could be utilised for practical biocontrol of the insect pests in future.
|
|
|
Use of entomopathogenic fungi in biological control against sweetpotato whitefly Bemisia tabaci
ŘEHOŘOVÁ, Markéta
The thesis is analyzing effects of selected species and strains of entomopathogenic fungi on the synchronized population of Bemisia tabaci under optimal and sub-optimal conditions. The following species of fungi were used during the experiments: Aschersonia aleyrodis, Lecanicillium lecanii (former Verticillium lecanii), Isaria fumosorosea (former Paecilomyces fumosoroseus) a Beauveria bassiana. There was a experiment of mortality of all these fungi in the frequency of 7, 14, and 21 days, while all these experiments were made under the same conditions (concerning temperature and humidity) in order to keep all the results comparable. In the case of Isaria fumosorosea, the experiment was taken also under sub-optimal conditions in order to compare effectiveness of this significant fungi, both under the optimal conditions (relative air humidity 95-100 %, temperature 25{$\pm$}1°C), and sub-optimal conditons (relative air humidity bellow 75 %, temperature 25{$\pm$}1°C). Greater attention was also given to A. aleyrodis which represents one of the most important fungi on the field of whitefly combat.
|
|
| |
|
|
Vzájemná kompatibilita entomopatogenní houby \kur{Isaria fumosorosea} s dalšími druhy entomopatogenních hub
OUŠKOVÁ, Šárka
This thesis is focused on evaluation of the compatibility of entomopathogenic fungus Isaria fumosorosea with different species of entomopathogenic fungi and mycoparasitic fungi at different temperatures. The strains of species Beauveria bassiana, Metarhizium anisopliae, Lecanicillium muscarium, Coniothyrium minitans and Clonostachys rosea f. catenulata were selected for experiments base on compatibility. The results showed that combination of I. fumosorosea with species L. muscarium is compatible. The species do not limit to each other in the environment at all temperatures (15, 23 and 25 °C). On the other side, fungus I. fumosorosea in combination with other species have affected their growth and spore production. The efficacy of entomopathogenic fungi against larvae Tenebrio molitor was evaluated. The most effective species against larvae were species I. fumosorosea, B. bassiana and M. anisopliae. On the contrary, the smallest effective was observed after infection larvae by L. muscarium. Mycoparasitic fungus C. rosea f. catenulata was not able to directly infect larvae of T. molitor. This species did not infect healthy larvae. However it is able to infect weakened individuals or is growing as saprotrophs on the cadavers.
|
|
|
Genetic variability of \kur{Isaria} genus in Czech Republic
ČÁPOVÁ, Aneta
My diploma thesis deals with genetic variability of entomopathogenic fungi of the Isaria genus encountered in the Czech Republic. Individual representative of the genus can be found in soil where they attack all developmental stages of insects, giving preference to larvae and pupae. The Isaria fungi find application first and foremost where plants have to be provided biological protection. In case of mitosporic fungi is the precise identification very difficult, taxonomy is often unclear in many genera, including the genus Paecilomyces/Isaria to demonstrate their polyphyletic nature. The fungi are classified primarily with reliance on morphological studies. The most common markers used to identify fungi are the shapes and sizes of their conidia and the biological properties (germination of spores, tests of biological efficiency). Identification made in consideration of the morphological markers is inaccurate and very variable. To overcome those accuracies, there are very useful molecular DNA markers, which can be relevant in ecology, biology and in fungi genetics. This paper relies on applying the ITS region (Internal Transcribed Spacer) as a molecular marker. ITS regions are partial constituent rDNA carrying no code - that is why the regions are likely to accumulate evolutionary changes in the DNA sequence, which makes them suitable for extensive use in taxonomic analyses of many organisms. The study results in a phylogenetic trees constructed by comparing different sequences of ITS regions obtained from the samples of entomopathogenic fungi of the Isaria genus gathered in the Czech Republic during the monitoring stage 2013 to 2014. Thereunder detection of Isaria sp. occurring in the Czech Republic.
|
|
|
Entomopathogenic fungus Isaria fumosorosea
OUŠKOVÁ, Šárka
Entomopathogenic fungus Isaria fumosorosea is among the species of entomopathogenic fungi used in biological control. Species I. fumosorosea has wide host range of insects in which is able to cause the primary diseases. Fungus I. fumosorosea most often infects greenhouse pests, such as aphids, thrips and mealybugs. I. fumosorosea is a pathogen, which naturally occurs in whiteflies populations, especially greenhouse whitefly T. vaporariorum and cotton whitefly B. tabaci. The Bachelor´s thesis is focused on a detailed description of the fungus I. fumosorosea and also characteristics of the other major genera of fungi (Beauveria, Hirsutella, Metarhizium, Nomuraea, Paecilomyces, Lecanicillium) including description of development cycle of entomopathogenic fungi. The thesis also contains a detailed description of the commercially available biological products based on I. fumosorosea (PFR-97, PreFeRal? a PreFeRal, NoFly) and their advantages and disadvantages, efficacy and general application of biological products on European market.
|
|
|
Evaluation of the effectiveness of chosen strains of entomopathogenic fungi in individual application and in application of more strain mixture
KRÁLOVEC, Jan
This diploma theses focuses on comparison of natural and intentionally inducated supressiveness of environment induced by application of entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, Isaria fumosorosea a Lecanicillium muscarium. In tests were evaluated the in vitro parameters as well as the effectiveness in vivo biotests on insect host larva Tenebrio molitor. The species of entomopatoghenic fungi were applied in suspensions, single strains and also in combination of two strains. In the in vitro conditions the possibilities of objective evaluation of the supresivity level were tested by using the CFU test (Colony Forming Units) on three different nutrient media (PDA, PDA + A , PDA + D), as one of the basic evaluation parameters. Further the germination tests were evaluated according to GI (Germination Index), determination of radial growth (comparison of median cultures) and interaction of strain suspensions on nutrient media PDA. In the in vivo biotests were watched the epizooties from suspensions of these entomopathogenic fungi on insect larva Tenebrio molitor in competitive test of strains according to FDI (Fungl development index) evaluation scala. Chosen larva covered by fully sporulating mycelium from epizootie were further evaluated in CFU test. The result were dominant strain/s on the larva from applied suspensions.
|
|
|
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.
|
guest ::
