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Evolution of genome size in streptophyte algae genus Zygnema and its ecological consequences
Lukeš, Jiří ; Čertnerová, Dora (advisor) ; Lučanová, Magdalena (referee)
Genome size is a trait that varies 64,000 × across eukaryotic diversity. However, this variability has nothing to do with the complexity of organisms. The amount of DNA itself is however related to a number of phenotypic traits of organisms. Specifically, studies conducted on plants look for possible connections between genome size and the ecological requirements of individual species. Similar studies in microscopic algae are not abundant and often face a number of methodological problems. This thesis presents genome size data obtained by flow cytometry for 129 representatives of the genus Zygnema belonging to 68 evolutionary lineages. Measurements revealed a genome size range within this genus from 0.22 to 5.06 pg. At the same time, several lines showing considerable variability in genome size were described, which in many cases indicates possible polyploidization in this genus. The identification of an identical GC base pair ratio in selected putative polyploid and monoploid representatives supported the hypothesis of polyploidization. The general correlation of cell size and genome size within this group was also validated. Due to the known phylogenetic relationships between the measured lineages, the genome size evolution in the genus Zygnema was reconstructed. Further, possible relationships...
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Genome size studies in plants - from intraspecific variation to ecological consequences
Lučanová, Magdalena ; Trávníček, Pavel (advisor) ; Leitch, Ilia (referee) ; Šmarda, Petr (referee)
Nuclear DNA content (genome size) is one of the basic characteristics of living organisms. In the Angiosperms, the range of genome size is 2,300-fold, which raises questions about the causes and consequences of this tremendous variation. This thesis deals with genome size in plants from the level of intraspecific homoploid variation, through intraspecific ploidy variation, to interspecies comparisons. On various study systems we investigated the dynamics and ranges of genome size variation, tried to reveal possible associations between genome size and selected biological traits, and assessed the extent to which differences in genome size are manifested at the ecological and evolutionary level. As a means of estimating genome size we applied flow cytometry (FCM). In Taraxacum stenocephalum we conducted a detailed study of its enormous genome size variation. We carried out crossings of parents with various genome sizes and compared these parental genome sizes with those of F1 offspring. We also attempted to reveal the association of genome size with various growth traits. In Galium valdepilosum and Arabidopsis arenosa we carried out an extensive flow-cytometric ploidy level screening and compared the distribution and ecological preferences of detected cytotypes. We studied the Andean genus...
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Genome size studies in plants - from intraspecific variation to ecological consequences
Lučanová, Magdalena
Nuclear DNA content (genome size) is one of the basic characteristics of living organisms. In the Angiosperms, the range of genome size is 2,300-fold, which raises questions about the causes and consequences of this tremendous variation. This thesis deals with genome size in plants from the level of intraspecific homoploid variation, through intraspecific ploidy variation, to interspecies comparisons. On various study systems we investigated the dynamics and ranges of genome size variation, tried to reveal possible associations between genome size and selected biological traits, and assessed the extent to which differences in genome size are manifested at the ecological and evolutionary level. As a means of estimating genome size we applied flow cytometry (FCM). In Taraxacum stenocephalum we conducted a detailed study of its enormous genome size variation. We carried out crossings of parents with various genome sizes and compared these parental genome sizes with those of F1 offspring. We also attempted to reveal the association of genome size with various growth traits. In Galium valdepilosum and Arabidopsis arenosa we carried out an extensive flow-cytometric ploidy level screening and compared the distribution and ecological preferences of detected cytotypes. We studied the Andean genus...
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Genome size studies in plants - from intraspecific variation to ecological consequences
Lučanová, Magdalena
Nuclear DNA content (genome size) is one of the basic characteristics of living organisms. In the Angiosperms, the range of genome size is 2,300-fold, which raises questions about the causes and consequences of this tremendous variation. This thesis deals with genome size in plants from the level of intraspecific homoploid variation, through intraspecific ploidy variation, to interspecies comparisons. On various study systems we investigated the dynamics and ranges of genome size variation, tried to reveal possible associations between genome size and selected biological traits, and assessed the extent to which differences in genome size are manifested at the ecological and evolutionary level. As a means of estimating genome size we applied flow cytometry (FCM). In Taraxacum stenocephalum we conducted a detailed study of its enormous genome size variation. We carried out crossings of parents with various genome sizes and compared these parental genome sizes with those of F1 offspring. We also attempted to reveal the association of genome size with various growth traits. In Galium valdepilosum and Arabidopsis arenosa we carried out an extensive flow-cytometric ploidy level screening and compared the distribution and ecological preferences of detected cytotypes. We studied the Andean genus...
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Genome size studies in plants - from intraspecific variation to ecological consequences
Lučanová, Magdalena ; Trávníček, Pavel (advisor) ; Leitch, Ilia (referee) ; Šmarda, Petr (referee)
Nuclear DNA content (genome size) is one of the basic characteristics of living organisms. In the Angiosperms, the range of genome size is 2,300-fold, which raises questions about the causes and consequences of this tremendous variation. This thesis deals with genome size in plants from the level of intraspecific homoploid variation, through intraspecific ploidy variation, to interspecies comparisons. On various study systems we investigated the dynamics and ranges of genome size variation, tried to reveal possible associations between genome size and selected biological traits, and assessed the extent to which differences in genome size are manifested at the ecological and evolutionary level. As a means of estimating genome size we applied flow cytometry (FCM). In Taraxacum stenocephalum we conducted a detailed study of its enormous genome size variation. We carried out crossings of parents with various genome sizes and compared these parental genome sizes with those of F1 offspring. We also attempted to reveal the association of genome size with various growth traits. In Galium valdepilosum and Arabidopsis arenosa we carried out an extensive flow-cytometric ploidy level screening and compared the distribution and ecological preferences of detected cytotypes. We studied the Andean genus...
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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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