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The genus Neotinea Rchb.f. in Europe
Vavřina, Štěpán ; Chumová, Zuzana (advisor) ; Vosolsobě, Stanislav (referee)
The thesis deals with the genus Neotinea from the phylogenetic, molecular and ecologic points of view. Most of its species have been classified in the genus Orchis until the use of molecular methods. Within the Orchidoideae, Neotinea forms a sister clade to the genera Anacamptis, Serapias, Ophrys and Himantoglossum. Six species are accepted now. The current taxonomic circumscription calls for a revision under the influence of new knowledge. Especially in N. tridentata, which contains several well-differentiated lineages and is the ancestor of the tetraploid N. commutata. Also the relationship between N. lactea and N. conica remains unresolved. The genome size within the genus ranges from 6.48 pg in N. maculata to 31.14 pg in N. lactea. All species except N. commutata, whose tetraploid origin is debated, are diploid (2n = 42). Partial endoreplication is present in the genus. The range of endoreplicated DNA is relatively narrow regardless of differences in genome size. Species prefer open, slightly basic habitats. In mycorrhizal interactions they appear generalistic with a preference for Ceratobasidiaceae. At the level of reproductive strategies, the genus Neotinea prefers the generative mode over the vegetative one. N. maculata is autogamous, the other species are allogamous, food deceptive, with...
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Ability of plants to adapt to anthropogenic pollution
Vachek, Tadeáš ; Münzbergová, Zuzana (advisor) ; Dostál, Petr (referee)
Due to global climate change and human interventions, the environment is changing rapidly. This brings many stress factors that organisms must adapt to. One of the adaptive mechanisms currently widely discussed is rapid evolution, i.e., hereditary change based on natural selection occurring at an ecologically relevant pace. This work deals with the synthesis of knowledge about rapid evolution, the methodology of its research, and its role in the adaptive processes of plants to anthropogenic pollution, focusing on heavy metals in soil and artificial light at night. The collected studies indicate that heavy metals exert strong selective pressure that can lead to the separation of a tolerant population from the original within a few generations. However, the significance of artificial light at night as a selective factor for plant evolution has not yet been studied. Although individual studies deal with adaptive evolution in phototactic insects in response to artificial light at night, extensive research has not been conducted here either. From the general examination of the effects of artificial light at night on organisms (especially animals), both direct and indirect impacts on their functioning are evident, many of which have not yet been described in detail. Thus, the direct and indirect impacts...
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Variability of Lepidium campestre seed mass concerning nutrition
Tučková, Kristýna ; Mašková, Tereza (advisor) ; Dostál, Petr (referee)
Seed production allows plants to maintain their genetic diversity, survive in dormancy through unfavourable conditions and disperse to new distant sites. Seed's own size reflects the amount of provisions designated for its germination, thus the rate and success of its germination. Seed size can also suggest dispersion distance, a chance to avoid seed predators, and how likely the seedling will withstand unfavourable conditions right after germination and before the formation of necessary structures for growth independent of maternal supplies. In general, the more nutrients a plant acquires during seed production, the bigger the number or size of seeds it can produce. In some cases, more nutrient uptake can lead to the production of more numerous and bigger seeds simultaneously, however, the direction of increased investment in reproduction highly depends on plant species. This work studies the effect of nutrient gradient in the environment on the variability of seed size in Lepidium campestre. It explores how seed traits change along the maternal environmental nutrient gradient, specifically how their number, size and seed coat thickness responds to the gradient. Subsequently, this work discusses the persistence of the maternal nutrient effect in the second generation, phenomenon called the...
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Food composition and feeding selectivity of zooplankton
Lis, Jonáš ; Škaloud, Pavel (advisor) ; Čablová, Radka (referee)
Zooplankton are an important link in the food web between phytoplankton and higher tro- phic levels, and understanding their feeding preferences is the key to unraveling the functions and dynamics of aquatic ecosystems. Current knowledge of zooplankton food composition is limited, consisting mainly of laboratory experiments that have revealed different hunting strategies and selection of prey based on size and nutritional value. Recently, publications have emerged that, through the use of DNA metabarcoding, provide a completely new and comprehensive insight into the diversity of zooplankton diet composition, especially copepods, cladocerans and rotifers. These methods reveal that the feeding niches of copepods and cladocerans are distinct and do not overlap. In general, both groups are said to prefer mainly diatoms as their food, when available. The food niches of rotifers are so diverse that no clear trend can be established for the entire phylum. Cyanobacteria appear to be the main source of energy for zooplankton and are proba- bly consumed by metazooplankton largely as secondary prey when consuming ciliates and other heterotrophic prey. Furthermore, differences in feeding niches between species are known and can be partly explained by their vertical distribution, and different levels of feeding...
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Mesocestoides spp. - the spectrum of species, hosts, and life cycle modes
Zavadil, Ondřej ; Horák, Petr (advisor) ; Skála, Vladimír (referee)
Tapeworms of the genus Mesocestoides, which belong to the order Cyclophyllidea, are parasites of carnivorous vertebrates. Their larvalstages of tetrathyridiaare found in a wide range of tetrapod intermediate hosts. Within the genus, there is an anomalous species Mesocestoides corti, whose tetrathyridia reproduce in hosts by asexual longitudinal division. There is no mention of the possibility of such reproduction in other species. Thus, the laboratory strain of M. corti is widely used as a model organism that is well maintained under in vivo and in vitro conditions due to its asexual reproduction. Four other species are known to occur in the genus and are described by both morphological and molecular data. The remaining known species are named only on the basis of morphology. Adults are characterised by their rare morphology. This includes the ventromedian position of the genital atrium, the paired vitelline glands, and in gravid proglotids, developed paruterine organ, which contains eggs with oncospheres. The life cycle has not been yet explained, but it is assumed that the putative cycle involves three hosts. An alternative hypothesis considers the possibility of a two-host life cycle.
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The importance of the Alps as a refugium in the Quarternary climate cycle with a focus on molluscs.
Gelnarová, Barbora ; Juřičková, Lucie (advisor) ; Coufal, Radovan (referee)
The Alps are a well-known glacial refugium, an important biodiversity hotspot and a centre of endemism for many species. This is due to their topological variability and the high heterogenity of their habitats, which thus provide a home for different species of organisms. In particular, the Eastern Alps represented an important glacial refugium and contributed to the survival of countless different species during the Quaternary climate cycle. This bachelor thesis is a literature review of mainly zoological publications that focus on the study of glacial refugia of terrestrial gastropods in the Alps. A large part of the thesis is devoted to the reasons for the considerable biodiversity, and especially the endemism, of this region. Another part deals with the postglacial dispersal spread of terrestrial gastropod species from their refugia. Key words: Alps, refugium, endemism, biodiversity, Quarternary, postglacional spread, molluscs, paleobiology
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Nonindigenous amphibian and reptile species of the Near and Middle East
Pazderková, Marie ; Šmíd, Jiří (advisor) ; Brejcha, Jindřich (referee)
This literary review summarizes information about twelve reptile and amphibian species, which are nonindigenous for the Near and Middle East. The studied area comprises the following states: Bahrain, Egypt, Iraq, Iran, Israel, Jordan, Qatar, Kuwait, Lebanon, Oman, Yemen, Saudi Arabia, Syria, Turkey, United Arab Emirates, Palestine. Nonindigenous species are introduced to new localities mainly via human causation. It can be either unintentional, such as transportation of the animal along with agricultural crops or exotic plants, or intentional, such as releasing the animal into the wild by breeder. Introduction of nonindigenous species can have unfortunate consequences for the stability of the indigenous ecosystem. From a human point of view, nonindigenous species can negatively affect local agriculture. Key words: Nonindigenous species, invasive species, Near East, Middle East, ecosystem, introduction, reptile, amphibian
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The importance of polyploidization in the evolution of grasses of the tribe Triticeae
Papoušek, Lukáš ; Urfus, Tomáš (advisor) ; Chrtek, Jindřich (referee)
Polyploidization, as a process of chromosome set multiplication, represents one of the most significant forces that shaped the evolution of angiosperms. Therefore, understanding the mechanisms of polyploidization is also important. It most often originates through unreduced gametes (less so through somatic polyploidization). Autopolyploids are the result of polyploidization within one species, or population, while the formation of allopolyploids is preceded by interspecific hybridization. Polyploidization also played a major role in the tribe Triticeae (Poaceae), which includes economically significant crops (wheat, rye, and barley). The taxonomy ofthe entire tribe, especially the generic concept, has been based on genomic concepts in recent decades. However, taxonomy is considerably complicated, particularly due to hybridization, or allopolyploidization. The result of allopolyploidization and even hybridization itself is a reticulate pattern, and it is not at all easy to determine the boundaries between taxa, even at the generic level. Triticum aestivum can be considered a model species for the study of allopolyploidy, both due to its economic significance and its origin through several rounds of hybridization events. Although allopolyploidy prevails, autopolyploidy can be encountered to a lesser...
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Comparison of alternative forms of cohabitation in the Czech Republic and France
Houdková, Sylvie ; Lederer, Vít (advisor) ; Frinta, Ondřej (referee)
Comparison of alternative forms of cohabitation in the Czech Republic and France Abstract The main objective of this thesis is to provide a detailed and systematic view of different types of alternative forms of cohabitation in two different countries, in the Czech Republic and in France, using descriptive, analytical and comparative methods. This thesis is divided into six parts. First three parts are focused on French legislation. The first part introduces the French legal order and its liberal approach to homosexuality in general and to various forms of cohabitation. The second part describes in detail the Civil Solidarity Pact, registered partnership of its kind, its development over the years, as well as main reasons of its rising popularity in French society. It also provides a brief comparison with the institution of marriage in order to fully understand the advantages and disadvantages of the Civil Solidarity Pact. The third part of this thesis is concerned with concubinage, a very informal alternative form of cohabitation, also embodied in French legal order. The following fourth and fifth parts describe the conservative approach of the Czech Republic to various forms of cohabitation over the years and their main advantages and disadvantages in comparison with France. It points to the division of...
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Sugars and other sweeteners
Krejčí, Martina ; Dostálová, Jana (advisor) ; Panovská, Zdeňka (referee)
The bachelor thesis deals with the topic of sugars and other sweeteners. In the theoretical part, a brief overview of carbohydrates in terms of nutrition, composition and basic breakdown is given. In detail, attention is then paid to specific types of natural energy sweeteners, non-energy sweeteners and polyols. The health effects of these sweeteners, the history of their use and, in the case of sugar, their consumption and production are discussed. Particular space is devoted to the legislation, control and safety of some non-energy sweeteners. Part of the work focuses more specifically on the artificial sweetener aspartame and the cases concerning its safety and effects on human health. The aim of the bachelor's thesis was to identify the range of table sweeteners and syrups, to create a list of them and then to assess the most common types of syrups sensorially. Another objective was to find out what sweeteners the general public and high school students use, whether they prefer beverages with artificial sweeteners, and to find out their opinion on the safety and control of artificial sweeteners. The practical part firstly deals with market research in 13 shops, 6 drugstores, 6 pharmacies and 3 health food stores. An inventory of 52 types of table sweeteners and 46 types of syrups offered in the...
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