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Vliv teploty vody a intenzity světla na raný vývoj sumečka afrického v komerčním chovu
PROKEŠOVÁ, Markéta
The successful production of quality early fish stages is crucial for artificial rearing fish species. Nevertheless, it is quite a problematic process, because fish as poikilothermic organisms are highly sensitive to various environmental conditions. Moreover, both fish embryos and larvae are more affected by biotic and abiotic factors (such as predation, stocking density, temperature, light, pH, salinity, oxygen saturation, feeding availability, or their interactions) than older juveniles or adults. Most fish processes such as reproduction, metabolism, survival, development and growth can be considerably (positively, negatively or not) influenced by these conditions. Therefore, it is important to understand their impacts on fish stages during embryonic, larval, juvenile, adult, and eventually the senescent period. Then, following the application of new knowledge to the practise, especially species- and age-specific optimal conditions, should result in higher survival, better growth rate, well developed fish without deformities and lower cannibalism. The objectives of the present thesis were to assess the effect of water temperature and light intensity on the early development (embryonic and larval period) of African sharptooth catfish as a perspective fish species for freshwater intensive aquaculture. Due to its great characteristics (for instance fast growth, ability to breathe atmospheric air, rearing at high stocking density) this species can meaningfully contribute to the global aquaculture production which is expected to rise in the coming years. However, there are still some difficulties in the early rearing African sharptooth catfish regarding the cannibalism, feeding, survival and necessity of detailed information about the effects of some abiotic factors and their interactions.
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Nové postupy biomonitoringu cizorodých látek ve vodním prostředí
ČERVENÝ, Daniel
Within the presented work, several approaches of biomonitoring were studied. A well-established method for human health risk assessment was applied to evaluate the quality of fish from open waters in the Czech Republic. As this work is targeted on sport fishermen, who frequently consume their own catches, besides the publication in scientific journal, a brochure with results of this study was distributed via the Czech Fishing Union. Health risks for consumers related to the consumption of wild fish were found strongly species and locality dependent. As there is no risks related with the consumption of carp (Cyprinus carpio) at all investigated sites, frequent consumption of predatory fish should be avoided at some fishing grounds. The use of passive samplers has become more and more attractive in the last two decades. As these devices are able to mimic the biological uptake of chemicals, their potential for replacing fish as bioindicators in routine biomonitoring programmes is evident. In our study, the comparison between analysis of fish tissues and POCIS extracts from selected sampling sites confirms this idea about interchangeability of these indicators in the case of PFASs as target pollutants. Moreover, no metabolic transformation of contaminants present in water take place in passive samplers contrary to living organisms, thus these reflect the actual contamination at the locality more precisely. The use of passive samplers completely fulfils the internationally accepted principles of Replacement, Reduction, Refinement (the three R´s). Another promising approach using YOY fish as bioindicators was evaluated within the present study. Multispecies samples of YOY fish homogenate was found as a better indicator for wide range of pollutants than muscle tissue of adult fish within one species from the same locality. As all inner organs and tissues are presented in analysed samples, more target pollutants in higher concentrations are detected compared to the muscle of adults. Besides the higher sensitivity in pollutants detection and quantification, practical and economic benefits are of concern in the case of the YOY fish approach. The YOY fish approach also particularly fulfil the three R´s strategy, as sampling of this age group of fish has a smaller impact on the environment than the sampling of adults. In case of mercury, that was found as a limiting contaminant for the consumption of fish from open waters in the Czech Republic, a nonlethal method of finclips sampling can be used for the monitoring of this compound in aquatic environments. Besides the monitoring, our optimised method for the estimation of muscle tissue concentrations could be used for human health risk assessment as well. The difference between real muscle concentrations and concentrations estimated using our method differs less than 10% in most of the investigated localities. Benthic organisms are an important part of the food web in aquatic environments, but insufficient information about its contamination is available. In another study included in this thesis, first evidence about bioaccumulation of certain pharmaceuticals in benthic organisms was described. Although, pharmaceuticals are generally considered to be not accumulative in organisms, our study proved that certain pharmaceuticals have bioaccumulation potential. From this finding, it is evident that not only the concentrations of pharmaceutical dissolved in water but also the diet represents an important exposure pathway of contamination by these compounds for organisms (fish) inhabiting aquatic environments.
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The effect of pyrethroid based pesticides on fish
RICHTEROVÁ, Zuzana
Pyrethroids are ones of the most used pesticides worldwides. The widespread use and high stability of pyrethroids lead to the assumption of that their occurrence in the environment could be quite frequent. They can reach water ecosystem as pollutants. Residues of pyrethroids are not only detected in the water column, but also in sediments and in fish tissues. The first study was devoted to the product Nexide containing 60 g.l-1 of active substance gamma-cyhalothrin. Tested Nexide concentrations were 5, 25, 50, 100, and 250 µg.l-1. Early life stage test was used.Common carp (Cyprinus carpio) was tested. There were significant mortalities in all concentrations except the lowest concentration during the trial. The lowest concentration tested 5 µg.l-1 only caused a slightly increased mortality. This lowest concentration influenced the growth in length and weight negatively, decelerated ontogenetic development, and made the body surface of the individuals darker. Histopathology of individuals from this concentration revealed dystrophy in liver. Examination of kidney, intestine and gills did not show significant histopathological differences compared with control. The evaluation of selected parameters of oxidative stress demonstrated a significantly higher activity of detoxification enzyme glutathione-S.transferase (GST) and a significantly lower activity of defensive enzyme glutathione peroxidase (GPx) compared with the control group. The other examined parameters of oxidative stress such as catalase (CAT), glutation reductase (GR), and lipid peroxidation determined by using the thiobarbituric acid-reactive substances (TBARs) were comparable to the control group. Changes in oxidative stress parameters suggest that exposure of the organism to the product Nexide in the given concentration leads to dysbalance of defensive enzymes. The second study was devoted to the product Cyperkill 25 EC containing 250 g.l-1. Tested Cyperkill 25 EC concentrations were 7.2, 36, 72, 144, and 360 µg.l-1. The procedure of the trial was the same as the preceded one. There were 100% mortalities in all concentrations except the lowest concentration during the trial. The lowest tested concentration 7.2 µg.l-1 allowed 90% of individuals to stay alive till the end of experiment. The lowest concentration influenced the growth in length and weight negatively and decelerated ontogenetic development compared with the control. Any individual exposed to this concentration did not reach juvenile stage until the end of the trial. Dark pigmentation was visible in 68% of these exposed individuals on the last day. Similar darkening was visible in individuals from higher concentrations shortly before death too. Histological examination did not revealed significant changes in intestine, liver, kidney, and gills compared with the control group. Evaluation of selected parameters of oxidative stress demonstrated significantly lower activities of GST, GR, and GPx. Activities of CAT and TBARS were comparable with the control group. Changes in oxidative stress parameters suggest that exposure of the organism to the product Cyperkill 25 EC in the given concentration could induce oxidative stress and interfere with the activities of antioxidant enzymes. The presented thesis summarises actual data about pyrethroids and their influence on fish. The demonstrated effects confirm high susceptibility of early developmental stages of fish to tested pesticides. When interpreting the results, we have to take into account the fact that studies showed this risk even on single pyrethroid substances. But water organisms are exposed to many other more or less toxic products and substances in a real environment. These xenobiotics could react with each other and their mixture could even potentiate negative effects. The performed studies also clearly show the significant differences in the sensitivity of embryonic and embryolarval tests.
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Iniciace pohybu byčíku, signalizace a regulace pohyblivosti spermií ryb: fyzikální a biochemické řízení
PROKOPCHUK, Galina
The current study attempted to shed light on the regulatory processes and response arrangements of fish spermatozoa during the course of maturation and motility initiation. The first intent of this study was to improve the understanding of the mechanism underlying the acquisition of potential for sperm motility in sturgeon. Up to present work, the physiological process underlying sperm maturation in this species has not been described at all. Our results showed that sperm maturation in sturgeon occurs outside the testes because of dilution of sperm by urine and involves the participation of high molecular weight substances as well as calcium ions present in seminal fluid and/or urine. The second aim of the present study was to investigate the coping mechanisms in fish spermatozoa with osmotic and ionic activating mode, as well as in spermatozoa of euryhaline fishes, to various environmental conditions. We showed that alteration of environmental osmolality might affect the fish sperm in different ways, depending on fish species and modes of spermatozoa motility activation either osmotic or ionic mode. In response to osmotic stress caused by hypotonicity, carp spermatozoa regulated the flow of water across their cell membrane and increased their cytoplasmic volume during their short motility period. In contrast, no indications of sperm volume changes were observed neither in sterlet nor in brook trout spermatozoa, both of which having an ionic mode of motility activation. We also examined the mechanism by which sperm motility triggering in euryhaline fishes can adapt to a broad range of environmental salinity. Our results demonstrated that spermatozoa of euryhaline tilapia, Sarotherodon melanotheron heudelotii, reared in fresh-, sea- or hypersaline water can be activated in hypotonic, isotonic or hypertonic conditions of swimming milieu, provided Ca2+ ions are present at various levels. It was established that the higher the fish rearing salinity or the more hypertonic ambient media at spermatozoa activation, the higher extracellular concentration of Ca2+ ions is required. The results obtained in the present study allow suggesting that osmolality is not the main factor inhibiting sperm motility inside the testis in the S. melanotheron heudelotii. A third aim of this study was investigation of the regulation of motility initiation process and description of flagellar beating initiation in chondrostean spermatozoa. We detected that K+ inhibition of sperm motility in sturgeon can be by-passed due to the pre-exposure of sperm cells to a high osmolality shock prior to its transfer to K+-rich swimming media. Thus, we hypothesized that sturgeon spermatozoa may be activated by use of an unexpected signaling pathway, independent from regular ionic stimulation. The successive activation steps in sturgeon spermatozoa were investigated by high-speed video microscopy, using specific experimental situation, where sperm motility initiation was delayed in time up to several seconds. At motility initiation, the first couple of bends formed at the basal region begins to propagate towards the flagellar tip, but gradually fades when reaching the mid-flagellum. This behavior repeats several times until a stage where the amplitudes of bends gradually reach similar value, what eventually leads to sperm progressive displacement. The total period needed for the flagellum to switch from immobility with rigid shape to full activity with regular propagating bends ranges from 0.4 to 1.2 seconds. In conclusion, the results of the current study bring valuable pieces of information into the general understanding of the processes of maturation of fish spermatozoa, their adaptability to different physical and biochemical circumstances, the extra- and intra-cellular signaling as well as the regulatory mechanisms of motility activation in fish spermatozoa.
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The use of (nano)oxides for metal and metalloid stabilization in contaminated soils
Michálková, Zuzana ; Komárek, Michael (advisor) ; Luke, Luke (referee)
The main objective of the thesis was to evaluate the potential of selected Mn and Fe (nano)oxides for the stabilization of metals and metalloids in contaminated soils. The research was focused basically on three materials - commercial nanomaghemite (Fe III), nanomagnetite (Fe II,III) and a synthetic amorphous Mn oxide (AMO). The main aim of the work was to provide a complex view on the chosen stabilizing amendments regarding not just their direct influence on contaminants mobility and stabilization mechanisms, but also their stability and alterations in soil conditions together with influence on soil microorganisms and higher plants. Firstly, adsorption properties of the tested materials towards Cd, Cu, Pb and As were investigated. In this context, the most effective material showed to be the AMO reaching one to two orders of magnitude higher adsorption capacities than Fe III and Fe II,III under given experimental conditions. Interestingly, the rate of As(V) adsorption onto AMO was increasing with increasing pH as a result of high pHzpc of the AMO (8.1) and significant dissolution of this phase at lower pH values. As a next step, the influence of (nano)oxides on metal(loid)s mobility and other physico-chemical soil characteristics after application to contaminated soil was examined. Again, the AMO proved to be the most efficient in reducing mobile pools of Cd, Cu, Pb, Zn and As. On the other hand, Fe III and Fe II,III addition had generally less significant effects on contaminants mobility. AMO application further resulted in an increase of soil pH connected with AMO dissolution and unwanted decomposition of soil organic matter. When (nano)oxides alterations in soil conditions were observed, MnCO3 coatings were identified on AMO surface while no significant changes were recorded for Fe III and Fe II,III. As the MnCO3 formation was connected with increased AMO stability, AMO particles synthetically covered with MnCO3 coating (denoted as SM AMO) were prepared. Although the SM-AMO had a lower mass loss in soil than pure AMO, the stabilizing efficiency was almost the same for both materials. The differences in surface composition of both materials were decreasing with time as MnCO3 naturally precipitated on the AMO surface in soils while the SM AMO coating was gradually dissolving. When investigating the effect on soil microbiota, AMO efficiently promoted soil microbial activity while no significant changes were observed in the case of Fe III and Fe II,III. The AMO was also able to reduce the uptake of Cd, Pb and Zn by sunflower (Helianthus annuus L.), eliminate Zn phytotoxicity symptoms and increase biomass yield. On the other hand, toxic levels of Mn released from the AMO in an acidic soil were found in sunflower tissues. AMO application is thus recommended for contaminated neutral or slightly alkaline pH with a higher cation exchange capacity in order to avoid unwanted release of Mn. Finally, various types of AMO-biochar composite sorbents were recently prepared and field experiment focused on stabilization of Cd, Pb, Zn and As using studied materials is currently under preparation. The combined results from the thesis highlight the importance of a complex experimental approach dealing with all parts of the contaminated soil environment in order to obtain complete information about the efficiency and usefulness of any newly developed stabilizing amendment.
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Management of production populations of forest tree species utilizing methods of mathematical programing
Hořejší, Matouš ; Lstibůrek, Milan (advisor) ; Stejskal, Jan (referee)
Breeding of forest tree species is a great opportunity for the entire forestry sector to succeed in the present modern World. Genetically improved forest trees have much better growing quality and they can sustain higher stress and unfavorable climatic conditions.
Efficient algorithms are necessary for optimizing and establishing seed orchards. These should optimally select clones as parents in future seed orchards. In the present thesis, we developed model, based on mathematical programming methods, which creates mix of clones with the maximum breeding value and constraints on genetic diversity.
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Evaluation of genotypic response of winter wheat production interventions
Bláha, Tomáš ; Faměra, Oldřich (advisor) ; Pavel, Pavel (referee)
Sources used in this thesis concerns the cultivation, the development and the growth of wheat and its recommendation for agro-ecological conditions such as requirements for the crop, influence of the agricultural technologies to underground parts, fertilization of wheat, the optimum sowing date and sowing depth. In the next part of literature search there is an information about response of winter wheat for chemical protection including treatment morforegulator of growth. The end of literature search deals with the composition of wheat grain and its potential influence to quality.
The methodological part is devoted to independent description of characteristics of the varieties which are included in experiment. Data for evaluation are based on literature published by ÚKZÚZ. This part summarizes the equipment used for conducting an experiment. Equipment consists machinery and laboratory equipment.
The experiment was located at two places - in Úhřetice near to Chrudim and in Krukanice near to Plzeň. Both places are valuated in the essay - description of altitude, soil type etc.
Evaluated results of experiments are at the end. The conclusion of my thesis is that more comfortable climate for growing wheat is in Úhřetice - the average yield is for almost 20 % higher than in Krukanice. Other conclusion is about late sowing date which reduces yield and about increasing number of antifungal treatment increases the yield. Each of the varieties are valuated in the next part and the best treatment options for them are recommended. One fungicide treatment is proposed resistance to disease (Bohemia, Seladon), dual fungicide treatment is recommended for the rest of varieties. Field evaluation of disease shows that intensity of the treatment must respond to the current situation (according to the year).
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Effect of water deficit on the energy content of individual plant organs in selected species of leafy vegetables
Šimůnková, Petra ; Hnilička, František (advisor) ; Česká, Jana (referee)
This work presents the impact of water deficit on dry mass production and photosynthetic accumulation of energy on every single plant´s organs of selected plant species. As a chosen experimental material were taken plants of Spinacea oleracea "Matador" sort and Tetragonia tetragonioides.
Spinacea oleracea and Tetragonia tetragonioides plants were grown in containers 11x11cm large in mixture of garden substrate A with silicon sand (2:1) in 2 variations placed in FAPPZ greenhouses. One variation was for control and second was exposed to stress reaction. Control variation had been watered for whole time of experiment with 50ml of water 2 times per week. Stressed one had been watered after puncturing and 6. taking until the end of experiment.
During the plant´s ontogenetic evolution had been monitored dry mass´s weight on singular plant´s organs. With usage of burnt calorimetry method had been monitored capacity of photosynteticaly accumulated energy in dry mass. Quantity of netto energy had been found out by dry burning adiabatic calorimeter LAGEST MS 10A.
From the gained results emerge, that plants of Tetragonia tetragonioides have 2 times higher weight growth apart from Spinacea oleracea. Control plants of Tetragonia tetragonioides have higher weight by 25,5% (123 mg) compared to the plants growing in water deficit. Likewise higher weight of roots had been observed on control plants (41 mg) compared to the stressed plants (40 g). Control spinach plants had higher weight of above-ground biomass by 19,5% compared to the stressed ones (43 mg). Roots of control plants had lower weight compared to stressed variant by 2960 mg.
From the results emerge, that plants of Tetragonia tetragonioides have higher weight of roots dry mass and above-ground biomass compared to the Spinacea oleracea plants.
Burning heat without ashes was on above-ground biomass of control plants Tetragonia tetragonioide on 15,96 kJ.g-1 level and on stressed plants 14,93 kJ.g-1 . In case of Spinacea oleracea plants was amount of control plants energy 14,98 kJ.g-1 and on stressed 14,21 kJ.g-1.
Burnt heat without root ashes of Tetragonia tetragonioides control plants was higher by 1.11 kJ.g-1 then on stressed ones (13,19 kJ.g-1). In case of Spinacea oleracea plants was amount of roots energy on control plants 11,90 kJ.g-1 and on stressed 11,72 kJ.g-1 .
Based on measurement were verified differences between species in reaction on water deficit and observed characteristic. From measuring emerged, that Spinacea oleracea plants are more sensitive on effect of water deficit compared to the Tetragonia tetragonioides
plants, which is more tolerant. Next thing observed is, that there are differences in amount of dry mass and rate of burnt heat in relation on effect of water deficit.
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The influence of time in feed enrichment with unsaturated fatty acids to selected parameters of pig carcass value with regard to the fatty acid composition of intramuscular fat
Pantoflíček, Jiří ; Čítek, Jaroslav (advisor) ; Miloslav, Miloslav (referee)
The thesis aims to evaluate the impact of aliment with higher contents of unsaturated fatty acids, consumed for a different period of time, to utilitarian attributes of pigs before a slaughter, with respect to the composition of fatty acids in the intramuscular fat of tested animals.
The factors that influence the quality of meat are interior, exterior and technological. Among the qualitative markers of quality of meat we rank the share of meat and fat, acidification rate, color, viscosity, contents of intramuscular fat (marbling), smell, taste, juiciness and delicacy. Together with hygienic and nutritive attributes, consumers and processors consider these technological and sensory aspects to be the most important.
The ultimate goal of this thesis is to compare the impact of different length of feeding soy oil on parameters of pork meat quality and growth.
However, the interference of growth attributes was inconclusive and the test result came similar in different groups of tested pigs.
What was influenced by adding the soy oil into the feed is the fatty acids profile. The contents of fatty acids remained unchanged in every test group. Over time the content of monounsaturated fatty acids decreased. The most significant change occurred in representation of polyunsaturated fatty acids, which increased in the test groups with longer period of feeding with enriched feed, mostly at the expense of monounsaturated fatty acids.
The differences between the test groups of pigs were statistically inconclusive; therefore the soy oil enrichment did not worsen the technological parameters of meat and fat quality.
The longer period of feeding the soy oil enriched feed led to significant increase in polyunsaturated fatty acids. According to the findings, adding the soy oil into the feed will have no effect at all if done short time before the slaughter.
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Use of Festuca arundinacea for decorative lawns
Doskočil, Jan ; Svobodová, Miluše (advisor) ; Hrevušová, Zuzana (referee)
Use of Festuca arundinacea for decorative lawns
Summary
Festuca arundinacea is briefly bentgrass with broader and coarser leaves. Hardly perennial grass, native to Europe, is well known for its high resistance of dry weather, low intensity of maintenance and resistance of high use. These qualities gains thanks to its well-developed and deep root system, which is capable to gain water and nutrients from deeper parts of soil. Its use is in places with high use, like a race-course, edges of roads or vineyards alleyway. Today, in time of global warming, its usage becomes more important for park purposes and low-input turfs, where is its higher resistance against biotic and abiotic stresses, mainly against drought, utilized. Festuca arundinacea complement well with Poa pratensis in turf.
Goal of this work was to evaluate turfs with Festuca arundinacea and chosen grass species under different mowing frequency. According to hypothesis frequency shouldn´t affect turf coverage. Coverage should be same with different mixture composition with Festuca arundinacea.
The experiment was performed on experimental land of Czech university of Life Sciences Prague, Suchdol in 2015. Mixtures of Festuca arundinacea with Festuca rubra, Poa pratensis and Lolium perenne were seeded together with monocultures of these species in 2012. Mixture composition was 50/50 except mixture of Fesruca arundinacea and Poa pratensis, where the mixture was 75/25. There were conducted 63 plots, in 3 repetitions and in 3 different frequencies of mowing (by 14, 30 and 45 days). Each plot was 6 m2 big. The results were evaluated by analysis of variance ANOVA (P is smaller than 0.05) in program Statgraphics, version XV.
Influence of mixture composition to level of growth was significant. The highest level of growth has monoculture of Festuca arundinacea (10,6 cm). The lowest level of growth has monoculture of Lolium perenne (5,4 cm). Monoculture of Festuca arundinacea had the highest intensity of grow (0,07 cm/day) at 14-day frequency of moving. Lolium perenne has the lowest intensity of grow (0,02 cm/day). At 30-day frequency of mowing mixture of Festuca arundinacea with Poa pratensis has the highest intensity of grow (0,24 cm/day). The lowest intensity of grow has Lolium perenne (0,01 cm/day). The highest intensity of grow was at 45-day mowing frequency. The highest intensity of grow has mixture of Festuca arundinacea with Festuca rubra (0,75 cm/day). The lowest intensity of grow has monoculture of Lolium perenne (0,06 cm/day). Influence of mixture composition to coverage was statistically significant. The highest coverage has mixture of Festuca arundinace with Festuca rubra (81,3 %). The lowest coverage has monoculture of Lolium perenne (58,6%). Influence of frequency to level of growth was statistically significant. The highest level of growth has 45-day frequency of mowing (6 cm) and the lowest level of growth has 14-day frequency of mowing (3,8 cm). Influence of frequency to coverage was statistically significant. The highest coverage 14-day frequency of moving (76,5 %) and the lowest has 45-day frequency of growing (66,7 %).
The knowledge gained will be used for further compilation grass mixtures for park lawns. It turned out that it is better to prefer seeding mixtures with Festuca arundinacea than monocultures. To achieve high coverage and optimal intensity of growth with Festuca arundinacea was recommended to follow 30-day frequency of mowing.
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