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Diversity of Epilobium and methods to explore their hybridization
Kuchyňková, Lenka ; Kaplan, Zdeněk (advisor) ; Šemberová, Kristýna (referee)
Willowherbs (Epilobium) belong to the genera whose evolution is significantly affected by interspecific hybridization. Although this process often generates evolutionary novelties and leads to speciation, it can also result in genetic erosion and extinction. This thesis is mainly focused on the Czech Epilobium species that are potentially endangered by interspecific hybridization. The emphasis falls on the group of rare mountain willowherbs including E. nutans, E. alsinifolium and E. anagallidifolium. In addition to frequent interspecific hybridization, the research of this group is also complicated by the subtlety of distinguishing morphological features. The review also summarizes the available methods that can be used to study interspecific hybridization in the follow-up thesis.
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Morphological and ecological differentiation and distribution of taxa in the Galium mollugo group
Talpová, Julie ; Kaplan, Zdeněk (advisor) ; Štech, Milan (referee)
My thesis deals with three taxa of the polyploid complex Galium mollugo that occur in the Czech Republic. These are diploid G. mollugo and tetraploid G. album subsp. album and G. album subsp. pycnotrichum. These taxa are very similar to each other, their identification is difficult and exact values of the quantitative characters used for their separation are unknown. To date, there has been no study based on flow cytometry (FCM) and classical morphometrics analysis in this complex. By using them I wanted to bring new results and fill the gaps in scientific research. Primarily, I was investigating whether the individual cytotypes can be distinguished based on different genome size using FCM analyses. Another aim was to determine whether it is possible to define morphological and ecological differences between diploid and tetraploid taxa. The morphometrics included ordination and discrimination methods. I observed whether taxa could be distinguished by the naked eye and determined by measurement which characters are most suitable for identification. FCM analyses proved to be suitable to distinguish the two ploidy levels. I have been able to demonstrate by statistical methods that diploid and tetraploid taxa differ from each other, and I have also refined the characters that are most suitable for...
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Trabant engine modernization
Kočka, Martin ; Ramík, Pavel (referee) ; Kaplan, Zdeněk (advisor)
The aim of this thesis is to make a list of available knowledge of the P63 engine, found in the Trabant 601 cars. Overview of its advantages and disadvantages, proposal of possible design changes, which would lead to elimination of the disadvantages, while increasing the power output of the engine. Assembly of the engine using the proposed modifications.
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Spark ignition engine with variable compression ratio
Fűri, Peter ; Píštěk, Václav (referee) ; Kaplan, Zdeněk (advisor)
With the aim of reducing pollutant emissions from internal combustion engines, the application of stoichiometrically operated spark ignition engines, for light vehicles, has been overcoming the compression ignition engines market share throughout the past years. The ability of a substantial reduction of the primary harmful emissions (HC, CO, and NOx). Nonetheless, with increasing attention to CO2 emissions, the development of highly efficient downsized spark ignition engines turns to be of enormous interest. However, to enable high load operation on such downsized engines, the compression ratio must be reduced due to knock limitations, reducing the partial-load operations efficiency. The work tries to describe solutions that have already been developed by various car manufacturers and to describe in detail my proposed design solution for changing the compression ratio using two-stage system.
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Modification of a motorcycle spark ignition engine
Poulíček, Matěj ; Ramík, Pavel (referee) ; Kaplan, Zdeněk (advisor)
This diploma thesis is about possible modifications of four-stroke motorcycle petrol engines for increasing power. It also deals with the modification of the Aprilia Leonardo 250 engine from a 2-valve variant to a 4-valve variant, the simulation of this engine and the proposed solution in the GT SUITE. Attention is also paid to the strength control of the crank mechanism of the engine.
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Spark ignition engine with variable compression ratio
Fűri, Peter ; Ramík, Pavel (referee) ; Kaplan, Zdeněk (advisor)
With the aim of reducing pollutant emissions from internal combustion engines, the application of stoichiometrically operated spark ignition engines, for light vehicles, has been overcoming the compression ignition engines market share throughout the past years. The ability of a substantial reduction of the primary harmful emissions (HC, CO, and NOx). Nonetheless, with increasing attention to CO2 emissions, the development of highly efficient downsized spark ignition engines turns to be of enormous interest. However, to enable high load operation on such downsized engines, the compression ratio must be reduced due to knock limitations, reducing the partial-load operations efficiency. The work tries to describe solutions that have already been developed by various car manufacturers and to describe in detail my proposed design solution for changing the compression ratio using two-stage system.
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Evaluation of variability within Sparganium erectum using morphometrics, AFLP and flow cytometry
Píšová, Soňa ; Fér, Tomáš (advisor) ; Kaplan, Zdeněk (referee)
MSc. thesis is based on evaluation of intraspecific morphological and genetic variation of Sparganium erectum L. in the Czech Republic. Four intraspecific taxa were examined: S. erectum subsp. erectum L., S. erectum subsp. oocarpum (ČELAK.) DOMIN, S. erectum subsp. neglectum (BEEDY) RICHTER and S. erectum subsp. microcarpum (L.M. NEUMANN) DOMIN. Various approaches such as multivariate morphometric analysis (PCA, discriminant analyses), estimation of genome size by propidium iodide flow cytometry and molecular analysis of total genomic DNA (AFLP) were applied for study close related subspecies. Multivariate analysis of morphological characters of fruits (for 350 individuals from 63 native populations) presented some distribution to four closed groups. Partial overlapping was observed for S.erectum subsp. neglectum with subsp. microcarpum and subsp. oocarpum. Similar situation (overlapping subsp. neglectum a microcarpum) was observed within genome size. Remaining two taxa, S. erectum subsp. erectum and subsp. oocarpum, were well-differentiated using genome size data. Most important morphological characters on fruits useful for subspecies determination were: sterility of fruit heads, presence or absence of peduncle, distinct shoulder between upper and lower part, constriction below the shoulder, width of fruit...
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Biosystematic study of the Carlina vulgaris complex in Central Europe based on molecular and morphometric approaches
Mašková, Hana ; Kaplan, Zdeněk (advisor) ; Krak, Karol (referee)
The Carlina vulgaris complex in central Europe includes several lineages defined by their ecology, morphology and distribution. This diploma thesis is focused on relationships between the taxa recognized in the Czech Republic, namely Carlina vulgaris subsp. vulgaris, C. biebersteinii subsp. biebersteinii, C. biebersteinii subsp. brevibracteata and C. biebersteinii subsp. sudetica. Molecular analysis revealed two genetically defined groups. One includes samples from relict populations in western Bohemia and from high mountains classified as C. biebersteinii subsp. biebersteinii and C. biebersteinii subsp. sudetica. The other is represented by plants classified as C. vulgaris and C. biebersteinii subsp. brevibracteata. This genetic differentiation was also confirmed by morphometric analysis. However, relationships within these two groups remain unclear. The Czech populations of Carlina biebersteinii subsp. biebersteinii as well as of C. biebersteinii subsp. sudetica are closely related to the mountain populations in the Alps and Carpathians. Their occurrence in the Czech Republic is relict and they should be in focus of nature conservation. However, the separate taxonomic position of the claimed endemic C. biebersteinii subsp. sudetica is probably unjustified.
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Interspecific hybridization between Pulsatilla pratensis and P. patens
Krejčová, Nikol ; Suda, Jan (advisor) ; Kaplan, Zdeněk (referee)
This thesis deals with interspecific hybridization in sympatric populations of Pulsatilla patens and P. pratensis. The key aim was to assess karyological and phenotypic variation in the study group. DNA flow cytometry revealed three non-overlapping groups of genome sizes, corresponding to P. patens, P. × hackelii and P. pratensis. The frequency of interspecific hybridization was low, accounting to approx. 3% of analyzed plants. Morphometric analyses identified a set a reliable species-specific characters, including number of divisions the leaf, length of petiole the part of leaf, number of smaller parts of leaf and colour of blossom. Although the majority of hybrid individuals flowered and set fruits, their fertility was reduced considerably. The threat from interspecific hybridization to parental species is therefore rather low.
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