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Stanovení genetické distance výchozích šlechtitelských materiálů řepky ozimé
Papanová, Michaela
Bachelor thesis is compiled from both the literature review and the practical part. The first one contains a treatise on oilseed rape and its main use. Attention is also paid to methods and history of breeding of this crop. An integral part is also an introduction to the concept of genetic distance and the importance of gene banks. The second part contains information about the research focused on determination of genetic distance in selected samples of oilseed rape by ISSR method. The results of the analysis were used to identify possible duplicates in the crop collection as well as to determine the genetic erosion of the samples. Similarly, the results can be used in the breeding itself, especially when selecting the parental components.
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Impact of polyploidy on the invasive potential of Vicia cracca
Líblová, Zuzana ; Münzbergová, Zuzana (advisor) ; Mihulka, Stanislav (referee)
This work is about diploids and tetraploids of Vicia cracca species, the two commonly occurring cytotypes. The first part is devoted to the distribution of cytotypes of this species in the secondary range in North America. It was hypothesised that polyploid species become invasive more frequently than diploid species. Their greater success may be given by greater variability of genes obtained by polyploidisation and gene subfunkcionalizing. All invasive populations of Vicia cracca species involved in this study were tetraploid. Based on this we can say that only tetraploids are invasive in this secondary colonized area. Polyploid species can be better competitors thanks to their expected better growth characteristics and stress resistance. Therefore the second part of this work is testing the hypothesis that polyploids are more variable in size of different parts of the plant body and therefore more able to grow even in conditions that are not suitable for diploids. As predicted by the EICA hypothesis (evolution of increased competitive ability), secondary colonized area also provide more space for further evolution and we can expect that growth characteristics of plants from the invasive range will differ from plants of the same ploidy from the original distribution range. This part of the work...
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Hybridizace krokodýlů z evolučního a ochranářského hlediska
ZAJÍCOVÁ, Veronika
Interspecific hybridization is an interesting and important phenomenon from the scientific and conservation point of view. My thesis is focused on hybridization in Crocodilia based on literature review. In summary, interspecific hybridization is relatively common in this group either in the wild or captivity where is much common. Maximum values of genetic distance between hybridizing species of crocodiles are around 32%.
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Comparison of the rate of evolution in genes located on reptile sex chromosomes and autosomes
Kuldanová, Kateřina ; Johnson Pokorná, Martina (advisor) ; Reifová, Radka (referee)
According to the "faster-X effect", X-linked genes and Z-linked genes evolve more quickly than autosomal genes. This theory is one of the currently intensively studied topics in evolutionary research. However, performing high quality tests is difficult because the results are influenced by several factors - the effective size of the population of the gonosome, sexual selection, the dependency of mutation rate and selection on sex, and the mechanism of dosage compensation. Conservation of genes and possible differences between rates of evolution of autosomes also play a role and not all studies take this fact into account. This study shows some of the difficulties of paired comparisons of dN/dS ratios traditionally used to test faster-X or faster-Z effects and introduces the basis of a new method of comparison of the rate of evolution (CREC) based on relative genetic distances between three species. The CREC method reduces the influence of conservation of genes on results and is more applicable for testing faster-X or faster Z effects in such species where two species without homologic gonosomes can be found for comparison. In means of the development of this method, the faster-Z effect was tested on a dataset of 9 autosomal and 13 Z-linked genes in the six-striped long-tailed lizard (Takydromus...
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Impact of polyploidy on the invasive potential of Vicia cracca
Líblová, Zuzana ; Münzbergová, Zuzana (advisor) ; Mihulka, Stanislav (referee)
This work is about diploids and tetraploids of Vicia cracca species, the two commonly occurring cytotypes. The first part is devoted to the distribution of cytotypes of this species in the secondary range in North America. It was hypothesised that polyploid species become invasive more frequently than diploid species. Their greater success may be given by greater variability of genes obtained by polyploidisation and gene subfunkcionalizing. All invasive populations of Vicia cracca species involved in this study were tetraploid. Based on this we can say that only tetraploids are invasive in this secondary colonized area. Polyploid species can be better competitors thanks to their expected better growth characteristics and stress resistance. Therefore the second part of this work is testing the hypothesis that polyploids are more variable in size of different parts of the plant body and therefore more able to grow even in conditions that are not suitable for diploids. As predicted by the EICA hypothesis (evolution of increased competitive ability), secondary colonized area also provide more space for further evolution and we can expect that growth characteristics of plants from the invasive range will differ from plants of the same ploidy from the original distribution range. This part of the work...
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