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Genetic diversity within pennate diatoms: implications for taxonomy and ecology.
Urbánková, Pavla ; Kulichová, Jana (advisor) ; Trobajo, Rosa (referee) ; Poulíčková, Aloisie (referee)
In past decades, molecular methods helped to discover extensive diversity hidden in mor- phologically delimited diatom species. Diatom taxonomy awaits revision and molecular meth- ods will play an important role in this pursuit. DNA-barcoding is a relatively cheap and rapid way to incorporate molecular data in the diatomological research.The crucial step, which deter- mines its efficiency, is marker selection. Therefore, we examined the performance of candidate barcode markers in the model genus Frustulia. Molecular data from the study helped to sup- port delimitation of two new species, Frustulia curvata and Frustulia paulii. Similar to previous research, the best-performing markers were part of the large ribosomal subunit and part of the RUBISCO gene. We encountered a case where these two markers disagreed. Similar gene tree discordances might compromise molecular species delimitation, which is based on single molecular loci. The use of both markers in a dual-locus barcode can mitigate the risk and draw attention to problematic cases that merit further study. However, the superior mean of spe- cies delimitation, which we used to set species limits in the complex Eunotia bilunaris-flexuosa, provides algorithms that use multiple loci and accommodate our understanding of molecular evolution. Several...
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Genetic diversity within pennate diatoms: implications for taxonomy and ecology.
Urbánková, Pavla ; Kulichová, Jana (advisor) ; Trobajo, Rosa (referee) ; Poulíčková, Aloisie (referee)
In past decades, molecular methods helped to discover extensive diversity hidden in mor- phologically delimited diatom species. Diatom taxonomy awaits revision and molecular meth- ods will play an important role in this pursuit. DNA-barcoding is a relatively cheap and rapid way to incorporate molecular data in the diatomological research.The crucial step, which deter- mines its efficiency, is marker selection. Therefore, we examined the performance of candidate barcode markers in the model genus Frustulia. Molecular data from the study helped to sup- port delimitation of two new species, Frustulia curvata and Frustulia paulii. Similar to previous research, the best-performing markers were part of the large ribosomal subunit and part of the RUBISCO gene. We encountered a case where these two markers disagreed. Similar gene tree discordances might compromise molecular species delimitation, which is based on single molecular loci. The use of both markers in a dual-locus barcode can mitigate the risk and draw attention to problematic cases that merit further study. However, the superior mean of spe- cies delimitation, which we used to set species limits in the complex Eunotia bilunaris-flexuosa, provides algorithms that use multiple loci and accommodate our understanding of molecular evolution. Several...
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Spatial variability and diversity of phytobenthos and metaphyton
Černá, Kateřina ; Neustupa, Jiří (advisor) ; Schagerl, Michael (referee) ; Poulíčková, Aloisie (referee)
Spatial variability and ecology of phytobenthic algal assemblages in peat bogs Abstract The thesis concerns two main issues: spatial distribution of microalgal assemblages in the environment of temperate peat bogs, and determination of morphological plasticity of selected desmid species (Euastrum binale, Staurastrum hirsutum) under different pH-levels using geometric morphometrics. The principal aims can be summarized as follows: (1) to evaluate seasonal and spatial patterns of the distribution of algal assemblages in a temperate lowland peat bog; (2) to describe the small-scale spatial patterns of the distribution of algal assemblages in two different microhabitats of a raised bog; (3) to investigate the range of morphological plasticity of selected desmid species under different pH-levels; (4) to evaluate species diversity and disparity of desmids in peat bogs using methods of geometric morphometrics and their relation to environmental conditions. The spatial pattern of the distribution of algal assemblages was studied along a linear transect in the homogenous environment of a lowland peat bog within one year on different spatial scales (10cm, 1m, 10m). The seasonal dynamics were exhibited by an increase in diversity, and a decrease in dominance from May to October, with significant differences in species...
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