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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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Application of molecular methods in population genetic studies
Šurinová, Mária ; Münzbergová, Zuzana (advisor) ; van Loo, Marcela (referee) ; Mandák, Bohumil (referee)
A vast range of factors shape the genetic structure of plant populations. In this thesis, I focus on two of them. The first factor, polyploidization, is a process of chromosome set multiplication through whole-genome duplication within a single species (autopolyploids) or hybridization of two different species (allopolyploids). It rapidly brings changes into genomes, allowing species to occupy distinct niches, adapt to new habitats, colonize them, or adapt to changing environment in their native range. But it comes at a certain cost - difficulties in mitosis and meiosis, changes in cellular architecture. Furthermore, after cytotype establishment, new individuals have to deal with cytotype exclusion effect, competition with parental individuals and higher nutrition requirements. In this thesis, I present the effect of polyploidization on populations of three species- Arabidopsis arenosa, Aster amellus and Festuca rubra. The second factor changing the population genetic structure presented in this thesis is the fragmentation of populations. Population fragmentation can be caused by natural or anthropogenic activities and often leads to overall reduction in population size and reduced connectivity among fragments. Restricted gene flow may threaten long-term population survival due to inbreeding...
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Origin, inheritance and ecological sygnificance of apomixis in the genus Hieracium s.str.: the role of genetic and epigenetic mechanims
Pinc, Jan ; Mráz, Patrik (advisor) ; Hojsgaard, Diego (referee) ; Mandák, Bohumil (referee)
Apomixis (asexual reproduction by seeds) has the considerable potential in agriculture and crop breeding due to its ability to produce genetically identical progenies in a form of persistent propagules, i.e. seeds. However, the processes laying behind the origin of apomixis and connected molecular mechanisms are still unknown. Despite the fact, that apomicts are considered to be an evolutionary dead-ends, they are often more widely distributed than their sexual relatives (this phenomenon is commonly referred to as geographical parthenogenesis (GP). Although this phenomenon is studied for decades, its causes are still not fully understood. Importantly, several recent studies pointed out that apomicts with limited genetic variability can at some extent react to changing environment through changes in gene transcription by epigenetic modifications. It is generally assumed, that hybridisation and polyploidization played a crucial role in the emergence of apomixis. For this reason, presented studies test the putative origin of selected polyploid apomicts and if the interspecific hybridisation between diploid sexuals triggers polyploidization using predominantly polyploid and apomictic genus Hieracium s. str. Surprisingly, the presented study demonstrates the hybrid origin of almost all investigated...
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Phenotypic variability and evolutionary relationships among populations of Primula elatior along an altitudinal gradient
Konečná, Veronika ; Kolář, Filip (advisor) ; Mandák, Bohumil (referee)
Primula elatior represents a promising model for addressing the role of phenotypic plasticity vs. genetic basis of traits in populations differentiated along altitudinal gradients. Phenotypic plasticity is mainly exhibited by the extensive variability of the leaves. Genetic structure of P. elatior populations has been poorly studied so far, the first insights suggested potentially large intraspecific genetic variation. Therefore, the first aim of this study was to reveal the genetic structure as well as morphological and cytological variation of P. elatior populations in the central Europe and compare those to another two intraspecific taxa from the southeastern Europe. Further, I selected three target mountain regions to address the role of altitudinal differentiation for structuring genetic diversity. Finally, I evaluated the status of the putative endemic species Primula elatior subsp. corcontica from the Krkonoše Mts. Microsatellite analyses, multivariate morphometrics and flow cytometry were employed to evaluate variation of P. elatior populations. I identified six major genetic groups by genotyping 12 nuclear microsatellite loci in the study area of central and southeastern Europe with the clear separation of subp. intricata. Focused on the central Europe, three well-defined genetic groups...
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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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On the Origin of Chenopodium album by Means of Hybridization
Kondrysová, Eva ; Mandák, Bohumil (advisor) ; Mráz, Patrik (referee)
Diploma thesis deals with genetic variability and evolutionary relationships among selected species of the group Chenopodium album and is especially focused on the origin of hexaploid species C. album in the Czech Republic. The main aim of the study was detection of putative recent emergence of hexaploid C. album s. str. in mixed populations of diploid (C. ficifolium and C. suecicum) and tetraploid (C. strictum and C. striatiforme) species. To assess phylogenetical relationships I performed an analysis of nuclear microsatellite loci, that are suitable for detection parental lines within polyploid species. As long as microsatellite primers have been developed for studied group, therefore they had to be cross-amplified from closely related species C. quinoa. Three PCR multiplexes were assembled by cross-amplification of microsatellite primers. These PCR multiplexes were tested on representative sample sets to estimate genetic variability of individual microsatellite loci. A total of 911 individuals were analyzed from five localities from the Czech Republic. The results of analyses revealed (1) high interspecific differentiation, (2) gene flow among species of the same ploidy levels, (3) presence of hybrids among diploid species of C. ficifolium and C. suecium as well as among tetraploid species C. strictum...
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Hybridization of cattails Typha latifolia and T. angustifolia
Mašterová, Helena ; Fér, Tomáš (advisor) ; Mandák, Bohumil (referee)
This study investigates the hybridization of two species of cattails, Typha latifolia (Common Cattail) and T. angustifolia (Narrow-leaved Cattail) in the Czech Republic. The aim of this study was to determine, how often T. latifolia and T. angustifolia hybridize, whether hybridization is allowed by overlapping flowering time of these species and whether it is possible these species controlled cross in a culture. For detection of hybrid individuals were used microsatellite DNA markers, which allow to detect hybridization events and differentiate hybrids from the parental species. Molecular analysis revealed that hybridization of T. latifolia and T. angustifolia occurs in the Czech Republic, but it is not frequent. Of the 267 analyzed individuals, 130 individuals were pure species T. latifolia, 108 individuals pure species T. angustifolia and 29 individuals were hybrids. Of the hybrids, 23 were advanced hybrids, 5 were backcrosses and only one individual was F1 hybrid. Flowering time of T. latifolia and T. angustifolia overlaps, which allows hybridization, and flowering time to not act as a prezygotic reproductive isolation barrier and gametes T. latifolia and T. angustifolia can blend together. In controlled crosses the female spikes T. latifolia and T. angustifolia created seeds, but these were...
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The invasive neophytes' occurrence in the riverbank vegetation
Matějček, Tomáš ; Lipský, Zdeněk (advisor) ; Mandák, Bohumil (referee) ; Lacina, Jan (referee)
Resumé The aim of this thesis is to summarize actual results of the field research of invasive neophytes' occurrence in the riverbank vegetation of selected water courses in the Czech Republic. In total approximately 850 km of the riverbank vegetation was mapped using author's own method. The riverbank vegetation was defined according to Novak et al. (1986) as the vegetation belt along a water course with boundaries represented by the water surface and the riverbank edge. The occurence of 22 most important invasive neophytes (sensu Pyšek et al. 2002) was registered using a logarithmical scale (1 = 1-9 specimen, 2 = 10-99 specimen, 3 = 100-999 specimen etc.). Some related species were not recognized (following species were aggregated together: Galinsoga parviflora and G. ciliata; Solidago gigantea and S. canadensis; Parthenocissus quinquefolia a P. inserta and Reynoutria japonica, R. sachalinensis and R. × bohemica). In total, occurence of 17 taxons was registered. The field research was conducted during the summer period of 2006, 2007 or 2008. Development in the years 2006 and 2008 could be compared for 218 segments, that was mapped in both time relations. The occurrence of invasive neophytes (17 taxons) was registered for each of the 500 m long segments (in total 1693 segments was mapped). The number of...
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