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Taxonomic principles, reproductive systems, population genetics and relationships within selected groups of genus Taraxacum (Asteraceae)
Zeisek, Vojtěch ; Kirschner, Jan (advisor) ; Richards, John (referee) ; Majeský, Ľuboš (referee)
Chapter 3 Summary - shrnutí English and Czech summaries (abstracts) of the thesis. 3.1 English abstract Genus Taraxacum (Asteraceae), having ∼60 sections and 2,800 species, is known for its complicated evolutionary relationships and taxonomy due to processes like frequent hy- bridization, polyploidization, asexual reproduction, clonality and low structural morpho- logical variability. Various taxonomical concepts and approaches are reviewed, evaluated and discussed from point of view of their ability to deal with such a complicated genera as is Taraxacum. Various processes responsible for the complicated situation within Taraxacum are discussed and reviewed. Section Dioszegia, comprising T. serotinum and its allies, are an exception because only sexuals are reported for all the members of this group. On the basis of the analysis of mi- crosatellite (SSRs) variation, distribution and morphology, we addressed problems related to their mode of reproduction, among-population relationships, taxonomy and within- population variation. As a rule, outcrossing was the dominant mode of reproduction, with one notable exception: T. serotinum subsp. tomentosum (≡ T. pyrrhopappum) was autogamous and not heterozygous. A taxonomic revision of sect. Dioszegia recognizes T. serotinum subsp. serotinum (including an aberrant...
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Reproductive systems and possibility of hybridization in genus Arabidopsis
Vlčková, Veronika ; Lučanová, Magdalena (advisor) ; Rooks, Frederick (referee)
This bachelor thesis is a literature review focused on plants of genus Arabidopsis. Despite numerous studies dealing with the model species A. thaliana there are only a small number of papers about its closest relatives, especially certain aspects are completely neglected in present literature. Species of the genus Arabidopsis can be found almost all over the world but their development center is most likely in Europe. This thesis summarizes general information on all representatives of this genus with a focus on European territory and concentrate mainly on their reproductive systems and hybridization. Species of the genus Arabidopsis frequently hybridize with each other and between different ploidy levels within these species. Due to such numerous hybridization and polyploidizations, including past and recent ones, the taxonomy of this genus is extremely complicated and has not been fully elucidated yet. This paper also includes main methods of experimental study of the reproductive systems. This bachelor thesis is a theoretical basis for the subsequent master thesis, in which I will conduct an experimental study addressing reproductive modes and the possibilities of hybridization between different taxonomic representatives and ploidy cytotypes of group A. arenosa.
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