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The influences of biotic interactions on population biology of Sanguisorba officinalis
Větvičková, Anna ; Janovský, Zdeněk (advisor) ; Jičínská, Jana (referee)
Plants can interact with many different organisms on many trophic levels in their life. In this thesis I investigated how three biotic inertactions, powdery mildew infection, caused by Podosphaera ferruginea, predispersal seed predation by Dusky Large Blue (Phengaris nausithous) and Scarce Large Blue (P. teleius) and deer grazing affect life cycle and population biology of the Great Burnet (Sanguisorba officinalis L.). I also analysed their preferences of environmental conditions. Most of studied plant populations growth rates (λ) were lower than 1 and population decreased, but quite surprisingly for more populations vegetative reproduction was more important than reproduction by seeds. All intraction mentioned above affects more generative reproduction, and thus their influence on Great Burnet population dynamics is low, even with modelled maximal possible effect. Environment conditions analysis showed that powdery mildew occurs on sites with more flowering individuals, where spreading is very easy, butterflies preferred high, well noticeable flower heads grown high above other vegetation and host ant presence. For host ants' presence model locality was only significant variable.
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Methods of detection of fungal diseases applicable in plant phenotyping and remote sensing
Klem, Karel ; Veselá, Barbora ; Holub, Petr ; Urban, Otmar ; Mezera, J.
This methodology summarises findings from a comparison of three perspective methods of fungal disease detection applicable for remote sensing and plant phenotyping of fungal disease resistance. These methods are spectral reflectance, infrared thermal imaging, and blue-green fluorescence imaging. On the example of winter wheat infection with powdery mildew, stripe rust and brown rust the strengths and weaknesses of individual methods were demonstrated. From these results it is evident that all three methods are potentially applicable for non-destructive fungal disease detection, but their practical use may vary. Testing of spectral reflectance indices for the detection of fungal diseases showed particularly the high detection reliability of the red-edge and green band based spectral vegetation indices. Infrared thermal imaging has shown high detection accuracy for powdery mildew and brown rust, but lower for stripe rust. Blue-green fluorescence and thermal imaging seems to be also a very promising tools for evaluating the intensity and spatial distribution of infection on a leaf level.
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Mode of action of resistance inducers against powdery mildew in wheat
Grigová, Vendula ; Šašek, M. ; Věchet, L. ; Burketová, Lenka
One of the method, how to increase resistance of plants against disease without changes of their genom is use of phenomenon known as induced resistance. Plant protection in system of induced resistance is based on activation of defence mechanisms of plants by stimulation of methabolic and structural changes in plants. For induction of resistance is used many compounds of chemical and biological origin. This work informs about mode of action of inductors used in pathosystem wheat (Triticum aestivum L.) – powdery mildew (Blumeria graminis f. sp. tritici). Efficiency of cited inducers were analysed by means of markers genes expression and by finding out infective structures of Blumeria. Slight expression of WCI5 (wheat chemically induced gene) ) and WCK1 (gene encoding a MAP kinase in wheat) was detected. Test of germinability showed that BTH (benzothiadiazol) treatment and treatment of oak bark extract caused an inhibition of germinative activity of Blumeria graminis spores on wheat.
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