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Evolution of ascospore morphology and their dispersal in bryophilous Pezizales
Janošík, Lukáš ; Koukol, Ondřej (advisor) ; Trávníček, Pavel (referee)
Bryophilous Pezizales represent a species-rich group of fungi closely associated with bryophytes. Their ascospore morphology is highly variable and they strongly differ also in the genome size and ecology. They could thus represent an interesting model system for the research of evolution of ascospore morphology and their dispersal. The aims of my thesis were to test whether their genome size, number of nuclei in ascospores and ecology of host bryophyte influence their ascospore morphology and to experimentally test the effect of ascospore morphology on their active dispersal. I studied 52 species of bryophilous Pezizales. I reconstructed their phylogeny based on the sequences of three DNA regions, which I then used for the testing of relationships between individual variables using the phylogenetic generalized least squares. For the majority of species, I obtained measurements from morphometric analysis, genome size measurements using flow cytometry, and determined the number of nuclei in their ascospores using the fluorescent microscopy. I localised the infection apparatus and included also the ecological characteristics of the host bryophytes into the analyses. Using the experiments with horizontal ascospore discharge, I measured the distance of active ascospore ejection and recorded whether...
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Searching for the origin of high-altitude endemic harebells from Campanula rotundifolia agg. in central Europe.
Folbrová, Magdaléna ; Šemberová, Kristýna (advisor) ; Trávníček, Pavel (referee)
Complex Campanula rotundifolia agg. is rich in endemic species, especially in the high- elevated mountain ranges. Extreme climatic conditions in the subalpine habitats can lead to a convergence in plant's morphology between plants isolated in different mountain ranges. Because of the lack of morphological differentiation, it is very difficult to reconstruct the evolutionary history of bellflowers C. scheuchzeri from the Alps, C. bohemica from the Krkonoše Mountains and C. tatrae from the Western Carpathians. A similarity in morphology and the same ploidy level can suggest vicariance from a large area of an ancestor species. However, regarding the continuous morphological variation, the high-altitudinal endemics could have originated by local adaptation from originally low-land species. DNA-ploidy level and genome size were detected by flow cytometry. Taxonomically important characters were found using multivariate morphometric analysis. The phenotypic plasticity of the taxon C. tatrae was tested by a cultivation experiment. Genetic structure of the studied species was revealed using molecular marker - microsatellites (7 variable primers). Studied taxa were tetraploids, but some possessed different genome size. The morphological differentiation was mainly due to characters like calyx lobes length...
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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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Sources of variation in the genus Anthoxanthum L.
Chumová, Zuzana ; Trávníček, Pavel (advisor) ; Mano Loureiro, Joao Carlos (referee) ; Kopecký, David (referee)
The genus Anthoxanthum (sweet vernal grass, Poaceae) represents a taxo- nomically intricate polyploid complex with a large phenotypic variation and still poorly resolved evolutionary relationships. The thesis deals with Anthoxanthum sect. Anthoxanthum in Europe, which comprises five traditionally recognized perennials (A. odoratum, diploid and tetraploid A. alpinum, A. maderense and A. amarum) and three annuals (A. gracile, A. aristatum and A. ovatum). Combination of different methods (DNA flow cytometry, sequencing of nrDNA ITS and two plastid regions, fluorescence and genomic in situ hybridization, climatic niche characterization and spatio-temporal modelling) was used to investigate ploidy and genome size variation of the genus across its European range, and to clarify the species origin and phylogeny of its members. Eight taxonomic groups that predominantly corresponded to traditionally recognized species were delimited on the basis of genome size values and phenotypic variation. While our data supported the merger of A. aristatum and A. ovatum, eastern Mediterranean populations traditionally referred to as diploid A. odoratum were shown to be cytologically distinct and may represent a new taxon. Genuine intraspecific variation in genome size was detected within the genus and the evidence for...
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Evaluation of cytotype and morphological variability and hybridization rate in water-milfoils (Myriophyllum) in the Czech Republic and adjacent territories
Hrdinová, Magdalena ; Trávníček, Pavel (advisor) ; Koutecký, Petr (referee)
Myriophyllum L. (watermilfoil) belongs to one of the most invasive genus of the Northern Hemisphere. The three most agressive species, one of which is native to Europe (M. spicatum), are widespread throughout the majority of United states and two of them (M. aquaticum and M. heterophyllum) are becoming invasive in several Europaean countries as well. Therefore, Europaean populations of both native and invasive species, represents ideal place where to study processes which account for watermilfoils' invasivness. In this study, flow cytometry, morphometric analyses and germination experiments were employed to evaluate cytotype and morphological variability of Myriophyllum along with its potential to hybridize and propagate generatively. Five ploidy levels were detected in Europe, however no ploidy variability has been found within any species except for M. sibiricum (hexaploids and nonaploids) and one population of M. aquaticum (hexaploids and oktoploids). Flow cytometry proved to be useful tool for purposes of distinguishing species of different ploidy level and their potential hybrids. Nevertheless, the key species - M. sibiricum and M. spicatum - among which probably even more aggressive hybrids were recently identified, have similar hexaploid level. Thus flow cytometry cannot facilitate...
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Ecological consequences of polyploidization in populations of the wetland plant Butomus umbellatus
Rydlo, Jan ; Fér, Tomáš (advisor) ; Trávníček, Pavel (referee)
This thesis aimed on comparison of environmental requirements and morphological and biological traits of diploid and triploid cytotypes of wetland plant flowering rush (Butomus umbellatus), occurring in Eastern Slovak Lowland in unique mixed populations, and to develop primers for variable microsatellite loci suitable for further genetic studies. In total, 72 populations of Butomus umbellatus were found. The analysis of relative genome size by the flow cytometry (FCM) technique revealed 34 exclusively triploid cytotype populations, 8 exclusively diploid populations and 30 mixed populations of Butomus umbellatus. In mixed populations, the numbers of diploid and triploid individuals are quite equivalent and the plants create combined compact communities. Analyses of environmental characteristics of sites with specific cytotypes (PCA, RDA, ANOVA) revealed no difference in site requirements of diploid and triploid Butomus umbellatus plants. Morphometric analyses (PCA, CDA) of traits of 36 diploid and 54 triploid plants confirmed differing morphology of both cytotypes occurring in the nature. Subsequent replanting of these plants into pots and cultivation further increased these differences. The ratio of width and length of internal perianthium is the most reliable parameter to distinguish diploid and...
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Reproductive isolation between diploid and tetraploid cytotype of Vicia cracca and possibilities of evolution of this aggregate
Vlčková, Zuzana ; Münzbergová, Zuzana (advisor) ; Trávníček, Pavel (referee)
Master thesis investigates reproductive barriers in diploid-polyploid complex of Vicia cracca. Complex with basic chromosome number x=7 consists of diploid (2x=14), tetraploid (4x=28) and rare triploid (3x=21) cytotype. I studied prezygotic barriers between diploid and tetraploid cytotype: phenology of flowering, pollinators' behavior (preference of spieces of pollinators to cytotypes, sequence of visited cytotypes), variables, that could explain pollinators' behavior (amount of nectar as the main reward, size and amount of pollen grains as a potentional reward). To find out how strong the triploid block is, I analyzed ploidy of seeds and seedlings from mixed-ploidy population. The habitat isolation showed up to be the strongest reproductive barrier. Pollinator's behavior meaningfully contributes to isolation, phenology of flowering contributes only minimally. Index expressing rate of prereproductive barriers is 0,990. Pollinator Bombus pascuorum visited on one locality preferably tetraploid plants and Andrena sp. preferred diploid plants. Even though tetraploid plants produce more nectar, no other analysis showed pollinators' preference to tetraploid plants.
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Polyploid speciation of the genus Anthoxanthum in Europe
Khodlová, Zuzana ; Trávníček, Pavel (advisor) ; Štech, Milan (referee)
Eight of fifteen species in genus Anthoxanthum (Poaceae) can be found in Europe. Five of them are perennials forming A. odoratum complex, the remaining three are annual, more or less mediterranean taxa (A. aristatum, A. ovatum and A. gracile). Within the A. odoratum s. l. complex the following taxa are distinguished: widely spread A. odoratum s. str. (4x; 2n = 20), arcto-alpine A. alpinum (2x a 4x; 2n = 10 and 20), Madeiran endemic species A. maderense (2x; 2n = 10), endemic species of Balkan mountains A. pauciflorum (2x; 2n = 10) and the Iberian peninsula endemic A. amarum (?x; 2n ~ 90). The aim of this thesis is to clearify the unknown evolutionary relationships between the taxa, between the annuals and perennials, diploids and polyploids. The following questions should be answered in this study: 1) What is the origin and distribution of the rediscovered diploid perennial taxon and what is its relationship to the other members of the group; 2) What is the distribution pattern of the perennial taxa of the genus Anthoxanthum in Europe and what is their haplotype differenciation (overall distribution of the taxa and haplotypes and the existence of their sympatric occurence); 3) What evolutionary ties exist among the species and what is the origin of allotetraploid taxon A. odoratum s.str. The...
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