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Genomic approach in speciation studies
Habalová, Kateřina ; Hulva, Pavel (advisor) ; Mikulíček, Peter (referee)
Speciation, adaptation and hybridization are three concepts, each one referring to different process but having a common evolutionary context. Maternal line splits into two sister lines or only one line cleaves from maternal one during speciation. However it leads to formation of new species. Adaptation and hybridization can lead to formation of new species as well. New species arise by adapting to new conditions during adaptation. Within hybridization it is a desecendant of two different lines mating amongst themselves. Most of this thesis is being addressed to these issues, the lesser part is addressed to specific examples. The chapter about next-generation sequencing methods is also included, as these methods have been used more frequently recently. Key words: speciation, adaptation, hybridization, genomics, next-generation sequencing
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Watermilfoils (Myriophyllum) in the central Europe
Hrdinová, Magdalena ; Trávníček, Pavel (advisor) ; Prančl, Jan (referee)
Genus Myriophyllum L. (watermilfoil) belongs to one of the most species-rich genera within Haloragaceae (Saxifragales). It includes three invasive species, which are of major concern - European M. spicatum L., North American M. heterophyllum MICHX. and South American M. aquaticum (VELL.) VERDC. All of them occur in Central Europe as well as native M. verticillatum L. and M. alterniflorum DC. lacking more significant invasive growth up to now. It is not only its invasivness that makes genus Myriophyllum so fascinating. It also displays extremely high phenotypic plasticity which is accompanied by determination difficulties. Moreover, recent research indicates that Myriophyllum tends to hybridize producing more invasive hybrids than parental taxa. Such traits pose a formidable challenge to scientists to deal with possible future invasive growth of non-indigenous Myriophyllum species in Central Europe. Therefore, thorough study of factors influencing evolution success of plants should be conducted. One of the key factors seems to be polyploidy. Research into polyploidy offers a new approach to watermilfoil issues. Additionally, according to preparatory study all native Central European Myriophyllum species can be easily distinguished by flow cytometry. That enables to study polyploidy in an...
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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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Conservation aspects of endemism in Central Europe with special respect to genus Sorbus
Tesařová, Anna ; Urfus, Tomáš (advisor) ; Macková, Lenka (referee)
Endemit is an organism living exclusively within a particular area on Earth. There are several mutually interconnected mechanisms leading to endemism i.e. allopathic speciation, polyploidization, hybridization and apomixis. This thesis deals with describing particular modes of endemic speciation and their occurrence. The most significant concept is certainly discrimination of paleoendemites and neoendemites. Paleoendemites are very rare and within Central Europe occur scarcerly only in Western Carpathians. Neoendemites are hardly comparable among Central European states. The concentration of endemics is closely related to the global centers of diversity that are distributed in highly unbalanced way. The genus Sorbus is essential group with regard to endemism in Central Europe. That is why the experimental part of my thesis was focused on flowcytometric analyses (absolute genome size and DNA ploidy level) of 13 endemic Sorbus species. Triploidy was proved to be prevailing ploidy level. Among triploid samples 6% of variation was recorded. The absolute genome size of the remaining endemic taxa indicated tetraploid level.
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Genetic diversity and evolutionary history of Czech endemic taxa from the genus Dianthus
Kalůsková, Jana ; Suda, Jan (advisor) ; Chrtek, Jindřich (referee)
Abstract This MSc. thesis deals with karyological, genetic and phenotypic variation of selected taxa from the genus Dianthus L. in the Czech Republic and adjacent countries. The evolutionary history of the genus has been shaped by several microevolutionary processes, including interspecific hybridization, genome duplication, and edaphic speciation. These processes led to the origin of a number of phenotypically similar taxa, which are often restricted to a narrow geographic area. One subendemic and three endemic taxa occur in the Czech Republic. These (sub)species were used as model groups to gain insight into microevolutionary processes in small populations and the postglacial development of the genus in Central Europe. The thesis consists of three parts, each addressing different evolutionary phenomenon: Dianthus arenarius subsp. bohemicus is a critically endangered endemic psammophyte currently known from a single population in Central Bohemia. The site is also inhabited by widespread D. carthusianorum. Interspecific hybridization has been suspected on the basis of morphological characters, but this has never been confirmed by any other technique. I exploited differences in the number of chromosomes between both species and, with the aid of DAPI flow cytometry, estimated relative DNA contents of...
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Mapping of distribution of red deer and sika deer hybrids in Czechia using audio recordings - citizen science project
Nečasová, Monika ; Pipek, Pavel (advisor) ; Červený, Jaroslav (referee)
In the Czech Republic, as in other parts of Europe (e.g., British Isles), the native European red deer (Cervus elaphus) has been hybridising with sika deer (C. nippon), which was introduced from East Asia. The hybrids are fertile, and, therefore, can backcross with their parental species and threaten their genetic integrity. Offsprings of such multiple crosses are very difficult to identify according to their morphological traits, while more reliable genetic methods are financially and logistically demanding. This work follows the study of Long et al. from 1998, which showed clear differences in vocalization between red deer, sika deer and the first generation of their hybrids, and thus suggested the third way how to identify hybrids - bioacoustic analysis. We decided to test this method in the Czech Republic in a citizen science project, the aim of which was to map the distribution of parent species and their hybrids using audiorecordings of rut vocalisation. To allow more detailed analysis, we also recorded our own recordings on a professional recording device with a directional microphone. In total, 451 recordings were collected, of which only 263 with a vocalization of 162 individuals were selected for further analysis. Recordings from previous studies from Ireland (Long et al. 1998; Wyman et...
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Significance of polyploidy and hybridization in evolution of European taxa of genus Arum
Podobová, Tereza ; Urfus, Tomáš (advisor) ; Hojka, Jakub (referee)
Polyploidy and hybridization are significant evolutionary trends that occur in a wide variety of plant species. This bachelor thesis includes current knowledge and data on arums with a focus on polyploidization and hybridization of the genus Arum. The change in morphology depending on the polyploidy can affect not only pollination and the associated generative reproduction. Several studies have revealed a possible correlation between ploidy levels and geographical occurrence. Hybrids are rarely described, mainly on the basis of chromosomal numbers and morphology. Rare findings of natural hybrids could be more frequent in the future with more intensive research and could have medical potential. Key words: polyploidy, hybridization, Arum, geographical occurrence, spadix
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Evaluation of hybridization effect on fitness of eyelid geckos (Eublepharis, Gekkota) by performance tests
Kohoutová, Tereza ; Frýdlová, Petra (advisor) ; Sedláček, František (referee)
An interspecies hybridization is usually viewed from two sides - either as mistakes in a reproduction resulting in decrease of a hybrids fitness (e. g. loss or decrease of viability and fertility) or as a mechanism helping animals adaptively respond to environmental changes resulting in higher fitness. Fitness is usually represented as a set of correlates. One of the correlates is an organism performance which is represented by a set of maximal values from measured physical activities. This thesis focuses on the evaluation of the endurance and the bite force for gecko species E. macularius and E. angramayniu, their interspecies hybrids and intraspecies hybrids to determine their performance. The results show differences in the bite force among each of the tested groups. E. macularius has the lowest bite force, while the highest bite force was measured in E. angramayniu. The bite force of interspecies hybrids is intermediate in comparison to the parent species. Nevertheless, intraspecies hybrids of large form and white form of E. macularius exceeds their parents in measured bite force. The variability in bite force suggests a positive effect of hybridization on fitness. The bite force differences between the large form and the white form of E. macularius support the hypothesis that there exist more...
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