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Drought stress response of European beech seedlings monitored using physiological and optical indicators.
Červenka, Ondřej ; Lhotáková, Zuzana (advisor) ; Gebauer, Roman (referee)
One of the manifestations of global climate change is an increase in extreme temperatures and drought waves, while forecasts of future development indicate deepening negative impacts. The effect of these abiotic stress factors is reflected in the physiological state of the vegetation. It is therefore necessary to find suitable stress indicators that will help detect the worsening of physiological state of vegetation in time series. Indicators can be detected not only by physiological methods, but also optical ones, for further use of vegetation monitoring by remote sensing methods. Forest beech (Fagus sylvatica L.) is a native tree in our context, currently widely used in forestry for planting more species-varied communities of trees that are more resistant to the effects of climate change. The aim of the thesis was to study the responses of beech to drought stress using physiological and optical indicators. Beech seedlings (planting material from the nursery) were placed in containers in the experimental greenhouse for two experimental seasons, water supply was mediated by drip irrigation. The experimental material was divided into three groups with graded irrigation (control, moderate drought and drought). The watering regime consisted of three periods of drought and recovery phases with uniform,...
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Physiological status of young silver fir on stands with different microclimate using biochemical, and optical needle traits.
Kabilková, Eva ; Lhotáková, Zuzana (advisor) ; Pokorný, Radek (referee)
Silver fir (Abies alba Mill.) is a candidate tree species in the process of forest transformation especially of spruce monoculture stands (Picea Abies (L.) H. Karst.), thanks to its better growth characteristics in conditions of mild drought. However, fir, as a very shade tolerant tree, may be more susceptible to various abiotic stressors in more open forest canopies, and therefore it is necessary to study its ecological requirements in connection with the most effective possible application in forestry. In this thesis, the physiological state of young fir stands affected by different light microclimatic conditions, which were represented by different types of forest regeneration, was studied. Specifically, it is shelter-wood cut, which represents the likely highest degree of shading by mature trees, then natural regeneration under sparse canopy, gap cut and small clear cut, which represent a moderate degree of shading by mature trees, and last but not least, clear cut, which represents the lowest degree of shading. Physiological status was evaluated using biochemical and optical properties of the needles, and additional microclimatic conditions of the habitats, namely temperature and soil moisture, were also evaluated. Our results showed that the used biochemical and optical properties of the...
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Detekce příjmu a účinku herbicidů s využitím zobrazovací fluorescence chlorofylu, UV stínění fluorescence chlorofylu a modro-zelené fluorescence
Otáhalík, David
Abstract The diploma thesis is devoted to the problem of detecting the uptake and effect of herbicides using non-destructive methods of chlorophyll fluorescence imaging, UV shielding of chlorophyll fluorescence and blue-green fluorescence on model species of weed plants or plants simulating weed species (cornflower, white mustard) and model species of field crops (spring barley, field peas). Chlorophyll, flavonol, anthocyanin and NBI index were also used for detection, which were measured pointwise. The measurement of the methods took place on the 3rd and 8th day after the application of herbicides. It is clear from the obtained results that the methods used differ in their sensitivity to the action of herbicides with different mechanisms of action, but that their sensitivity also changes over time after application. At the same time, a significant interaction with the species according to its sensitivity to the given herbicide is also evident, but at the same time, some methods have recorded responses to the action of the herbicide even in cases of tolerance to the given herbicide, which may be caused by inducing defensive reactions in the plant, such as the accumulation of flavonols or anthocyanins. 3 days after the application of herbicides, the most statistically significant responses to the action of herbicides were found in the anthocyanin and chlorophyll index, the UV shielding of chlorophyll fluorescence and the current quantum yield of photosystem II (ΦPSII) parameter. On the other hand, the least evident reactions to the action of herbicides were found for the non-photochemical quenching parameter (NPQ) and the flavonol index. 8 days after the application of herbicides, the most statistically significant reactions were found for the blue-green fluorescence index, the chlorophyll index and the ΦPSII parameter. At least for the NPQ parameter and the flavonol index. The chlorophyll imaging parameter ΦPSII, the chlorophyll index and the blue-green fluorescence index, which were measured only on the 8th day after herbicide application, generally achieved the most statistically significant detections of herbicide intake and effect. The methods used thus demonstrate high potential. Detection methods have a high potential in assessing the intake and effect of herbicides, but it is necessary to consider the duration of herbicide action, the sensitivity of the species and possibly also the growth phase during application for own interpretation of the results.
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Detekce houbových chorob ječmene pomocí zobrazovací fluorescence a termálního zobrazování
Holzmannová, Kateřina
The main goal of this work was to perform a literature review of imaging methods for the detection of spring barley diseases, their advantages and disadvantages and to conduct an experiment on spring barley samples with different levels of fungal disease infection to compare disease detection using chlorophyll fluorescence imaging, UV fluorescence imaging and hyperspectral imaging in VNIR and NIR spectral ranges. The originally planned measurements on more diseases were performed due to governmental travel restrictions related to the coronavirus pandemic only for Pyrenophora teres barley infection. The achieved results show that all three methods have the potential for use in the field of early and non-invasive detection of P. teres infection, either for the purpose of aerial monitoring or in the phenotyping of resistance to P. teres. The best correlation to leaf infection was achieved with the parameter actual quantum yield of photosystem II (ΦPSII). This parameter shows a high linearity of relationship to P. teres infection, which gives the assumption of reliable detection in the whole infection range. With regard to the need for measurements from the proximity and also due to possible effect of changes in the intensity of solar radiation, this is rather a parameter applicable for plant phenotyping than for the monitoring of large areas. Very good results in the detection of P. teres infestation were also obtained using the UV fluorescence screening index. UV fluorescence screening also shows a very close relationship to the level of P. teres infection, but of a non-linear nature, where the UV fluorescence shielding index increases sharply with under a low level of infection and is less affected at higher level of infection. This means a higher sensitivity of the method to a small level of infection and may therefore have an advantage especially in the early detection of infection. The UV screening index also have considerable potential for the analysis of the disease spatial distribution at the leaf level, where UV shielding increases in areas around the infestation site but decreases significantly at the infestation site itself. In contrast, hyperspectral reflectance represents considerable potential for monitoring of large areas, because it can be evaluated not only from proximity but also from a drones, aircrafts or satellites. The highest correlation and linearity of relationship between P. teres infection was achieved for the index integrating the wider reflectance range 650-725 nm ANMB650-725. However, good results of estimating the level of infection were also achieved with simple vegetation indices such as NDVI and EVI. For the early detection of P. teres infection, the ARI index based on the anthocyanin absorption band, showing a sharp change in low infection level, seems to be the most suitable. This index also shows very good results of evaluating the spatial distribution of P.teres infection on the leaf, with ARI rising at the site of infection. The best results of the evaluating the spatial distribution of infection was demonstrated by the simple ratio of reflectances in the red and green band (RGR), which, however, shows less close relationship to the total P. teres on the whole leaf. Overall, it can be stated that all three methods have the potential to be used for monitoring of P. teres infection and for phenotyping of resistance to P. teres. For the selection of method, rather the key technical requirements e.g. if the total leaf infection is measured or the distribution of the leaf infection is evaluated, from what distance the measurement can be performed and what is the range of measured areas, and also whether it is necessary to detect low level of infection with high sensitivity at the onset of infection or it is more important to ensure a reliable estimate of the infection in the whole range.
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Evaluation of the physiological status of European beech in its plantings on localities following the gradient of its ecological valence
Palouš, Daniel ; Albrechtová, Jana (advisor) ; Tomášková, Ivana (referee)
European beech (Fagus sylvatica L.) is one of the dominant tree species in Europe, presenting a keystone species for forest ecosystem functioning. The ongoing climate change alters the environmental conditions in the areas of the current distribution of European beech, leading to stress. Concerning the critical health status of forests in the Czech Republic and other European countries, it's even more urgent to monitor the health status of forests. For this, tools for early detection of a stand's physiological status decline are needed. The aforementioned tools can consist of indicators of the physiological status suggested by this thesis. This thesis aims to evaluate the applicability and sensitivity of the preselected set of indicators of the physiological status of European beech to the gradient of environmental conditions (temperature, precipitation) within its ecological valence. Four stands of European beech presenting the gradient of beech's ecological valence were observed over the peak of one vegetation season. Stand Kocanda presented the microclimatic and ecological optimum; stand Hradecko was on the lower margin of the altitudinal gradient of European beech distribution and presented the limit of low water availability; stand Deštné was on the upper margin of the altitudinal gradient of...
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Cultivation, Monitoring and Application of Migroalgae Cultures.
RANGLOVÁ, Karolína
This thesis deals with microalgae mass cultures grown in laboratory as well as outdoor cultivation systems and a potential use of their biomass. Case studies illustrate the correlation of changes in growth rate with photosynthetic activity, physiological features and biomass composition under various conditions (high irradiance intensity, optimal/suboptimal temperature and the presence of some metalloids). The special attention was also paid to evaluation of the bioavailability of Se-enriched Chlorella biomass which is commonly used as a food supplement. As concerns methodology, photosynthesis monitoring techniques, namely chlorophyll fluorescence were employed as an important tool to estimate microalgae activity.
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Characterisation of Arabidopsis thaliana mutants psbo1 and psbo2
Nykles, Ondřej ; Duchoslav, Miloš (advisor) ; Hála, Michal (referee)
The PsbO protein is necessary for the function of the electron-transport chain of the thylakoid membrane in higher plants. In most of the angiosperms, including Arabidopsis thaliana, this protein has two isoforms termed as PsbO1 and PsbO2. Many authors tried to reveal the fundamental difference between the PsbO1 and PsbO2 with the help of the mutant lines which lack one of the isoforms. The problem is that the mutants in psbO isoforms do not possess the same level of PsbO as WT does. So we made psbo1isoL mutants. These lines contain only one isoform but their level of the whole PsbO is comparable to the level of the whole PsbO of WT. Results from these experiments suggest that if a psbo1isoL plant has the same amount of PsbO as WT does, there is no observable phenotype difference. Thus we were not able to identify, in the usual cultivation conditions, if there are any functional differences between PsbO1 and PsbO2 Following the above mentioned results, we would like to know conditions (if there are any) in which T-DNA insertion mutants psbo2 (respectively psbo2cr which are made with the use of the CRISPR/Cas9), which have only PsbO1 isoform, could be phenotypically distinguished from WT. With the use of usual cultivation conditions, we are unable to tell apart the psbo2 and psbo2cr from WT by the...
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Relationship between leaf biochemistry, physiology and specie's competitiveness in selected grasses of relict tundra in Krkonoše Mts.
Mamula, Petr Martin ; Lhotáková, Zuzana (advisor) ; Tylová, Edita (referee)
The Krkonoše (Giant Mountains) Arcto-Alpine Tundra is an area that is part of the Krkonoše National Park with a unique ecosystem and biodiversity. In history, this area was very fundamentally influenced by the intervention of man, who farmed here and thus caused the creation of today's rare matgrass (Nardus stricta L.) meadow ecosystem. Thanks to the low growth and sparse foliage of the matgrass, many other plant species grow in these matgrass meadows, which are often endemic and protected by the law. In recent years, however, the matgrass has been overgrown by other grasses, such as the hairy reed grass (Calamagrostis villosa J.F. Gmelin), which, due to its taller growth and dense canopy covering the surface, does not allow the growth of rare species such as matgrass. Therefore, the aim of this work was for matgrass (N. stricta) and three other selected species of grasses - tufted hair grass (Deschampsia cespitosa (L.) P. Beauv.), moor grass (Molinia caerulea (L.) Moench) and hairy reed grass (C. villosa), to identify, based on biochemical, structural and physiological foliar parameters, a parameter or a combination of parameters that could give competing fennel grasses a competitive advantage. Field research and collection of foliage samples, for subsequent laboratory processing, took place in...
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