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Evolutionary processes shaping the genus Urtica L. (Urticaceae) in Europe and adjacent areas
Rejlová, Ludmila
Although European flora belongs among the best explored, there are still several marginally studied groups. One striking example is the polyploid complex of Urtica dioica, with multiple rare diploid taxa, which are often found in remote and partly relict geographic ranges, in contrast to cosmopolitan tetraploid individuals, which occur in a variety of synanthropic habitats and have an unknown evolutionary history. The thesis primarily deals with the evolution of diploid taxa recognized in Europe and contiguous areas of Southwest Asia (Urtica dioica subsp. kurdistanica, U. d. subsp. pubescens, U. d. subsp. sondenii, U. d. subsp. subinermis). This can lay the foundation for understanding phylogenetic relationships and revealing the evolutionary history of polyploids (U. d. subsp. dioica). The study also concerns itself with other related species outside of the complex U. dioica, especially from the Mediterranean area. An extensive dataset of 7012 samples from 1317 populations in a cytogeographical study has been analyzed, which covers most of the currently accepted diploid subspecies of U. dioica. From the entire dataset, a set of 279 plants (evenly representing the geographical and morphological variation) was used to estimate the extent of phylogenetic and morphological differentiation. The...
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Evolutionary processes shaping the genus Urtica L. (Urticaceae) in Europe and adjacent areas
Rejlová, Ludmila ; Chrtek, Jindřich (advisor) ; Koutecký, Petr (referee) ; Temsch, Eva Maria (referee)
Although European flora belongs among the best explored, there are still several marginally studied groups. One striking example is the polyploid complex of Urtica dioica, with multiple rare diploid taxa, which are often found in remote and partly relict geographic ranges, in contrast to cosmopolitan tetraploid individuals, which occur in a variety of synanthropic habitats and have an unknown evolutionary history. The thesis primarily deals with the evolution of diploid taxa recognized in Europe and contiguous areas of Southwest Asia (Urtica dioica subsp. kurdistanica, U. d. subsp. pubescens, U. d. subsp. sondenii, U. d. subsp. subinermis). This can lay the foundation for understanding phylogenetic relationships and revealing the evolutionary history of polyploids (U. d. subsp. dioica). The study also concerns itself with other related species outside of the complex U. dioica, especially from the Mediterranean area. An extensive dataset of 7012 samples from 1317 populations in a cytogeographical study has been analyzed, which covers most of the currently accepted diploid subspecies of U. dioica. From the entire dataset, a set of 279 plants (evenly representing the geographical and morphological variation) was used to estimate the extent of phylogenetic and morphological differentiation. The...
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The variability of the species Urtica dioica in the Czech Republic
Rejlová, Ludmila ; Urfus, Tomáš (advisor) ; Vít, Petr (referee)
The genus Urtica L. is represented by three species occurring in the area of the Czech Republic. The most common Urtica dioica L. represents a highly variable group with number of intraspecific taxa. The most common source of variability in Urtica dioica is probably polyploidy (min. 2 ploidy levels - 2x and 4x). Another source of the variation in this species is dioecy. A small percentage of individuals in dioecious populations are actually monoecious. The study of these individuals can potentially extend our knowledge of the evolution of Dioecy. The species Urtica dioica is frequently confused with the closely related diploid taxon Urtica kioviensis Rogow., which relates to the study of Urtica dioica because of their similar ecological preferences and general affinity. The aim of this review is to summarize existing knowledge of the species with results of a pilot sampling and analyses, which identified several ploidy levels with the center of abundance of the relict diploid in primary willow-poplar forests of lowland rivers. These issues will be further examined in a subsequent master's thesis, with focus on the morphological differentiation and the affinity of ploidy levels. Since the rarest and the most targeted taxa, resp. cytotypes, of the genus Urtica occur exclusively in the willow-poplar...
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Variation of the species Urtica dioica in Central Europe
Rejlová, Ludmila ; Urfus, Tomáš (advisor) ; Mandák, Bohumil (referee)
Although the European flora belongs to the best explored at the global scale, still there are several largely neglected plant groups, which may surprise by marked variation. One of these groups is Urtica dioica s. l., consisting of vaguely described taxa (microspecies / subspecies) with indefinite distribution. The most important source of variation in U. dioica s. l. is probably polyploidy (2x, 4x; x = 13). The complex comprises an ubiquitous tetraploid cytotype (U. dioica s. str.) and several obscurely defined relict 2x taxa. The cytogeographical analysis through Europe (770 populations / over 3 200 individuals) revealed marked distribution pattern of U. dioica s. l. cytotypes. We identified 106 diploid populations (13%) and 633 (82%) tetraploid populations. For the first time we detected triploid and pentaploid level (from mixed populations). Prevailing tetraploid U. dioica s. str. is predominantly synanthropic, whereas diploid taxa strictly occur in primary and relict habitats (primarily alluvial forests, tundra, Mediterranean mountains). The analysis of the absolute genome size of individuals from U. dioica clade and other closely related taxa showed different values of 2x U. kioviensis (19 % higher than 2x U. d. subsp. subinermis) and 2x U. bianorii (33% higher than 2x U. d. subsp....
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Variation of the species Urtica dioica in Central Europe
Rejlová, Ludmila ; Urfus, Tomáš (advisor) ; Mandák, Bohumil (referee)
Although the European flora belongs to the best explored at the global scale, still there are several largely neglected plant groups, which may surprise by marked variation. One of these groups is Urtica dioica s. l., consisting of vaguely described taxa (microspecies / subspecies) with indefinite distribution. The most important source of variation in U. dioica s. l. is probably polyploidy (2x, 4x; x = 13). The complex comprises an ubiquitous tetraploid cytotype (U. dioica s. str.) and several obscurely defined relict 2x taxa. The cytogeographical analysis through Europe (770 populations / over 3 200 individuals) revealed marked distribution pattern of U. dioica s. l. cytotypes. We identified 106 diploid populations (13%) and 633 (82%) tetraploid populations. For the first time we detected triploid and pentaploid level (from mixed populations). Prevailing tetraploid U. dioica s. str. is predominantly synanthropic, whereas diploid taxa strictly occur in primary and relict habitats (primarily alluvial forests, tundra, Mediterranean mountains). The analysis of the absolute genome size of individuals from U. dioica clade and other closely related taxa showed different values of 2x U. kioviensis (19 % higher than 2x U. d. subsp. subinermis) and 2x U. bianorii (33% higher than 2x U. d. subsp....
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The variability of the species Urtica dioica in the Czech Republic
Rejlová, Ludmila ; Urfus, Tomáš (advisor) ; Vít, Petr (referee)
The genus Urtica L. is represented by three species occurring in the area of the Czech Republic. The most common Urtica dioica L. represents a highly variable group with number of intraspecific taxa. The most common source of variability in Urtica dioica is probably polyploidy (min. 2 ploidy levels - 2x and 4x). Another source of the variation in this species is dioecy. A small percentage of individuals in dioecious populations are actually monoecious. The study of these individuals can potentially extend our knowledge of the evolution of Dioecy. The species Urtica dioica is frequently confused with the closely related diploid taxon Urtica kioviensis Rogow., which relates to the study of Urtica dioica because of their similar ecological preferences and general affinity. The aim of this review is to summarize existing knowledge of the species with results of a pilot sampling and analyses, which identified several ploidy levels with the center of abundance of the relict diploid in primary willow-poplar forests of lowland rivers. These issues will be further examined in a subsequent master's thesis, with focus on the morphological differentiation and the affinity of ploidy levels. Since the rarest and the most targeted taxa, resp. cytotypes, of the genus Urtica occur exclusively in the willow-poplar...
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