National Repository of Grey Literature 16 records found  1 - 10next  jump to record: Search took 0.03 seconds. 
Seasonal dynamics of physiological parameters of Norway spruce needles in mountain forest in relation to water balance of the forest site
Bednář, Pavel ; Albrechtová, Jana (advisor) ; Gebauer, Roman (referee)
Norway spruce (Picea abies (L.) Karst.) is an important economic tree species in the Czech Republic, which is currently significantly weakened and dying under the impacts of climate change. In young spruce forest stand in mountain region that was artificially established after the large-scale disturbance of forests in the mid-1990s, on the "U Dvou louček" research plot represented by a small forest catchment of an area of 32.6 ha, located in the upper part of the Orlické Mountains at an altitude of 880 - 920 m a.s.l., and in site conditions of predominantly Abieti-fageta piceae - water balance measurements were carried out during the 2019 and 2020 growing seasons. At the same time, during the mentioned two years, in total 6 samplings of biological material were carried out according to a standardized sampling methodology, and laboratory analyzes were carried out on this material. Laboratory analyzes were focused on three established age categories of needles, namely 1, 2, and 4 or more years old. The biophysical parameters of needles were determined based on the measurement of structural parameters and concentrations of photosynthetic pigments - chlorophyll a, chlorophyll b and total carotenoids from samples extracted in DMF using a laboratory spectrophotometer. Optical properties of the needles...
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...
Spectrophotometric determination of chlorophyll
Rábová, Petra ; Vavrčíková, Veronika (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis is focused on determination of chlorophyll in leaves by the method of extraction spectrophotometry. The theoretical part provides information about photosynthesis, stress factors or plant adaptation, photosynthetic pigments (especially chlorophyll-a) and application of spectrophotometry and other methods of chlorophyll determination. The experimental part is focused on the application of the ecotoxicological test and, above all, it is evaluation by two independent methods. Specifically, it was determination of biomass growth inhibition and newly spectrophotometrical determination of chlorophyll mass. The results correlate with each other, therefore, the determination of chlorophyll seems to be an appropriate extension of usual evaluation methods of ecological tests.
Vliv kombinace biouhlu a zinečnatých nanočástic na rostliny kukuřice seté kultivovaných v in vitro podmínkách
Szomolaiová, Erika
Combined application of zinc oxide nanoparticles (ZnO NPs) and biochar could be a perspective tool for enhancing plant viability and mitigating a large scale of stresses in crops. To investigate effect of different concentrations of ZnO NPs (0, 50, 100 and 1000 mg/L), biochar, and their combination on corn plants (Zea mays L.), in vitro experiment took place. Zinc uptake in form of zinc NPs and possible effect of biochar on zinc uptake and accumulation were determined by atomic absorption spectrometry. A positive correlation between ZnO NPs concentration and zinc content in shoots was identified. There was no significant difference observed in plants treated with biochar. Physiological state of plants was evaluated by spectrophotometric analysis of photosynthetic pigments and secondary metabolites. The most significant effect was observed in content of phenolic compounds that increased with increasing ZnO NPs concentration. On the contrary, presence of biochar resulted in significant decrease (p < 0,05) of polyphenols.
Influence of high temperature and high light density on quantity and apportionment of photosynthetic pigments in plants
TROJÁČKOVÁ, Barbora
This thesis concerns about proportional content of photosynthetic pigments in plants of wheat (Triticum aestivum). The plants were cultivated at two different temperatures (20 °C and 30 °C) and in two different irradiations. Each cultivation took one month. Five plants per sample were taken from each cultivation box with different conditions. The samples were weighted and dehydrated to obtain data for growth curves. Amount of photosynthetic pigments was measured by spectrophotometry. Absorption for chlorophyll a, b and carotenoids was measured. These results were processed into tables and graphs where we can see that the trend of amount of photosynthetic pigments is obvious. This thesis confirms the hypothesis, that plants can adapt stress environment.
Genetic variability in growth, reproductive and photosynthetic parameters of plants and its changes by exogenously applied steroids
Rothová, Olga ; Holá, Dana (advisor) ; Motyka, Václav (referee) ; Hradilík, Jan (referee)
While animal steroid hormones are very well known and have been studied for a long time, in plants no steroid substances were known until relatively recently. Only in the second half of the past century brassinosteroids were discovered; later on, their hormonal function in plants was confirmed. Still a lot of unknown remains as regards their function in plant cells. This paper presents in its first part the evidence that brassinosteroids control in maize (Zea mays L.) grown under field conditions not only its morphology and yield but also some developmental/reproduction characteristics like e.g. number of female inflorescences or speed of the development of male inflorescences. Particular response of a plant depends, however, on the type of applied brassinosteroid, its concentration, and last but not least also on a particular maize genotype and developmental stage of the plant during applicatin. Impact of brassinosteroids on primary photosynthetic processes in plants has not been proven under these conditions, neither on the activity of photosystem (PS) I nor on the Hill reaction. No statistically significant differences in the content of photosynthetic pigments have been found either. Another topic dealt with in this thesis is the possible protective influence of brassinosteroids on plants...
Analysis of primary photosynthetic processes in conifers: A comparison of selected methods and their possible utilisation for the study of genetic variability
Palovská, Markéta ; Holá, Dana (advisor) ; Albrechtová, Jana (referee)
Conifers are important both ecologically and socioeconomically, however, same parts of their biology are not that well researched. This includes genetics and breeding and partly even physiology. Because quantitative genetic analyzes applied in breeding necessitate an analysis of a large number of samples, and conventional methods of analysis are quite time-consuming, certain parameters describing e.g. the activity of photosynthetic electron-transport chain (ETC) are considered for such use. Several methods of the measurement of the activity of photosynthetic ETC exist, but there are some problems with their usage in conifers. I studied this issue from different points of view in three parts of this thesis. 1) I compared the photosynthetic ETC activity in 8 species of conifers using chlorophyll (Chl) fluorescence measurements on intact needles and polarographic measurements in isolated chloroplasts. Each method brought different information. 2) I measured Chl fluorescence parameters, reflectance spectra and pigment content in 536 genetically defined trees of Pinus sylvestris L. Many parameters showed relatively high genetic variability and heritability. I have also determined the suitability of various reflectance indices to estimate pigment and water content of needles. 3) I have optimized the...
Vliv sucha a ošetření semen studeným plazmatem na stavbu a funkci fotosyntetického aparátu brukve řepky olejky
HANZAL, Jaroslav
In the period of global climate changes, the resistance of significant agricultural crops to drought has become from an economical point of view a very important topic. In order to achieve maximum productivity of agricultural crops, it is necessary to search for new technological approaches to enhance this resistance. Currently, one of the actual topics in this area is the possibility of seed treatment with cold plasma. The aim of this work is to reveal the degree of influence of cold-plasma treatment of seeds on the stress response of plants that had been grown under the influence of drought. The oilseed rape was chosen for this experiment intentionally because it remains a substantial agricultural crop with a huge variety of usage. The plants of rapeseed had been grown in fully-controlled conditions in a growth chamber. The selected photosynthetic characteristics had been checked in regular intervals and the stress response was evaluated on two variables: plants grown from seeds treated with cold plasma and plants grown from commonly used seeds. In total, three measurements of chlorophyll fluorescence and photosynthetic pigment content have been conducted. The first measurement in the beginning of development of the seedlings showed better drought resistance in nontreated seedlings but in the following second and third measurements it was vice versa: cold-plasma treated plants survived better in dry conditions. Results of the analysis of photosynthetic pigments suggest that the cold plasma treatment can obviously increase the resistance of seedlings of rape especially in conditions of long-term drought.
How trees resists the stress of city environment
ŠINDELÁŘOVÁ, Lenka
The aim of this diploma thesis was to find out the seasonal changes of the air pollution tolerance index (APTI) in London planetree (Platanus acerifolia) and small-leaved lime tree (Tilia cordata), which grow in Jiráskovonábřeží in České Budějovice near the busy urban roads. The research was conducted in August, 2015. The complete results of this research were summarized into a teaching presentation for pupils at primary schools, which shall show them the issues of urban stress for these two tree species, which are very often planted in cities. The APTI index consists of four parameters, which were needed to be found out for the APTI index could be established. These parameters for the APTI are: the content of chlorophylls in a leaf, the content of the ascorbic acid in a leaf, the relative water content in a leaf and the pH of the extract from a leaf. By the discovering ofthe values of these parameters, the APTI was counted and thanks to this APTI it was easier to determine, which of these two tree species is less or more stressed by air pollution on the particular location. Further, the fluorescence of chlorophyll, which is -next to the APTI index- another indicator of effect of stress on the physiological processes in a plant and measured fluorescence values were compared with values from the previous measuring in 2013. The results were statistically evaluated and processed into the tables and graphs. According to the results of the APTI index, the small-leaved lime tree has proved as more sensitive to air pollution in Jiráskovo nábřeží, the London planetree was more resilient from this point of view. By the comparison of the results of chlorophyll content and fluorescence from 2013 and 2015, it was found out that the year 2015 has proved as less favourable for both species.
Spectrophotometric determination of chlorophyll
Rábová, Petra ; Vavrčíková, Veronika (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis is focused on determination of chlorophyll in leaves by the method of extraction spectrophotometry. The theoretical part provides information about photosynthesis, stress factors or plant adaptation, photosynthetic pigments (especially chlorophyll-a) and application of spectrophotometry and other methods of chlorophyll determination. The experimental part is focused on the application of the ecotoxicological test and, above all, it is evaluation by two independent methods. Specifically, it was determination of biomass growth inhibition and newly spectrophotometrical determination of chlorophyll mass. The results correlate with each other, therefore, the determination of chlorophyll seems to be an appropriate extension of usual evaluation methods of ecological tests.

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