National Repository of Grey Literature 28 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Orchids as a model for research in ecophysiological adaptations of mycoheterotropic plants
Ponert, Jan ; Lipavská, Helena (advisor) ; Gryndler, Milan (referee) ; Chrtek, Jindřich (referee)
Perhaps all orchids are mycotrophic at early developmental stages, while majority of species photosynthesize at adulthood and only about 200 species remain fully mycotrophic for the whole life. Mycotrophy affects orchids at many levels. In this thesis, I focus on four aspects of orchid biology, which could be connected with mycotrophy: (i) systematics, (ii) genome size and endoreduplication, (iii) regulation of seed germination and (iv) mechanism of transfer of carbon and energy from fungi to orchids. There are over 27,000 recently recognized orchid species, nevertheless new ones are still discovering and old ones are revisiting. In this work I present a description of new species, Cleisostoma yersinii, and its morphological, anatomical, ecological and systematic characterization. Phylogeny reconstruction confirmed relationship with C. birmanicum. In the subtribe Podochileae, I reappraised the genus Campanulorchis to establish monophyletic but also morphologically defined group. For both abovementioned genera I prepared the artificial identification key. In the genus Dactylorhiza I revised taxa present in our country and I prepared an identification key which firstly mentions D. maculata subsp. elodes from Czech Republic. Orchid species diversity is probably reflected in genome structure. Results...
Cardamine dentata, its distribution in Central Europe and relatinoship to C. pratensis
Holič, Filip ; Marhold, Karol (advisor) ; Chrtek, Jindřich (referee)
This thesis summarizes the documented information on the distribution of Cardamine dentata Schult. of the family Brassicaceae in the Czech Republic; it deals with the chromosome numbers and with ploidy levels of this species. Microsatellite markers were used to evaluate the potential relationships of C. dentata with other species of the group C. pratensis. Using a revision of available herbarium material it was found that the optimal conditions for the occurrence of C. dentata in the Czech Republic are in the phytogeographical regions of Thermophyticum and Mezophyticum at altitudes of 150-650 m a.s.l. No karyological data on this species were previously published from the area of the Czech Republic; using the flow cytometry and chromosomes counting it was revealed that in the area of the Czech Republic, populations with decaploid and undecaploid levels of ploidy occur. With help of microsatelite markers, it was confirmed that plants of C. dentata are genetically different from the other species of the C. pratensis group. Keywords: Cardamine, Cruciferae, microsatelite markers, chromosome numbers, geographical distribution, Czech Republic
Microevolutionary processes in Cystopteris fragilis agg.
Ptáček, Jan ; Urfus, Tomáš (advisor) ; Chrtek, Jindřich (referee)
Polyploidization and hybridization are the main microevolutionary processes, which take place within pteridophytes and dominantly participate in their variability and further speciation. Reproductive strategies are also related with above mentioned processes, especially various type of apomictic reproduction, which play an important role within ferns (compared to Angiosperms). Polyploidization and hybridization take part in Cystopteris fragilis (L.) Bernh. (common fragile fern) and both are also recently participating in origin of new cytotype (mirrored by enormous proportion of mixed populations consisting off tetraploids to octoploids). The main goal of this diploma thesis is cytotype structure of particular stages within the life cycle of common fragile fern with evaluation of sporogenesis (viability, exospore length and number of spores), together with testing reproductive strategies of individual cytotype using flow cytometry. Moreover, an experimental hybridization is supplementing above mentioned aims of the diploma thesis. The main sources of variability seem to be restricted to tetraploids and pentaploids, whereas hexaploids produce only uniform progeny. Tetraploids form both diploid reduced and tetraploid unreduced spores (but only 1,97 % of total amount of spores). Pentaploids have variable...
Study of plant dispersal in river corridors using molecular marker
Fér, Tomáš ; Herben, Tomáš (advisor) ; Chrtek, Jindřich (referee) ; Tribsch, Andreas (referee)
5 Summary The thesis presents how the use of molecular markers (AFLPs and microsatellites) can help when studying plant dispersal in river systems. Analysis and interpretation of the spatial pattern of genetic variation allowed to address and discuss following aspects of long-distance dispersal in these linearly structured systems: (1) the extent of long-distance dispersal, (2) the intensity of vegetative long-distance dispersal, (3) unidirectional transport along the streams, and (4) dispersal among rivers. The first part of the PhD. thesis presents several general aspects of plant dispersal, methodological approaches used to detect dispersal, and possibilities of analysis and interpretation of the molecular data. It also gives a short introduction to the methodology used in the particular studies, summarizes the results of all studies, and discusses how differences detected by molecular markers correspond to dispersal possibility (e.g., by water, by wind) of the selected species. The second part contains a set of four papers, each focusing on a detailed survey of dispersal possibilities of one of four plant species within the river system of the Cidlina, the Mrlina and partly also the Labe Rivers (Czech Republic). Above- mentioned aspects of dispersal in river systems are further discussed in the light...
Organellar DNA diversity in some ornamental plants related to reproduction system and life strategy
Osama Mohamed Elansary, Hosam ; Štorchová, Helena (advisor) ; Bureš, Petr (referee) ; Chrtek, Jindřich (referee)
124 7. Conclusions The purpose of this Ph.D. work was oriented towards two points. 1. The analysis of organellar diversity among three plant species (Silene vulgaris, Silene latifolia and Aldrovanda vesiculosa). The three plant species had different morphological and physiological characters. The focus here was on two physiological points. 1.1. The reproduction system which is directly correlated with the mitochondrial DNA (in the case of CMS). This point was presented in the comparison between Silene vulgaris and Silene latifolia. 1.2. The different life strategy which is directly correlated with the organellar DNA diversity. This point was presented by the comparison between the two Silene species from one side and Aldrovanda vesiculosa from the other side. The later usually propagate vegetatively and live in different media (water), it present different life strategy under the umbrella of angiosperms. 2. The analysis of the inheritance of mitochondrial and chloroplast genome in Silene vulgaris. The study of this inheritance was facilitated by the high polymorphism available in the organellar DNA. This polymorphism could be detected by the different molecular markers used in this study. These molecular markers included either, gene coding regions markers previously used by D.E.McCauley and his team...
Evolutionary history of Orchidaceae in the Mediterranean basin
Jankolová, Lucie ; Ponert, Jan (advisor) ; Chrtek, Jindřich (referee)
The matter of this text is the Orchidaceae family occuring mainly in the Mediterranean basin. The selected genera from the Orchidinae subtribe are discuted, namely it is about Anacamptis, Neotinea, Ophrys, Orchis and Serapias genera. Different genera of this family have tendency to diversify to a different extent, some of them content thousands of taxa, another have orderly onely few dozens of them. The work is therefore focused on the genera themselves and on the factors, that may have had any influence on their diversification. Key words: evolution, radiation, mediterranean climate, Orchidaceae, diversification, diversity, Mediterranean basin
The origin and evolutionary significance of triploid hybrids in diploid-tetraploid contact zone in Tripleurospermum inodorum
Ryšavá, Hana ; Čertner, Martin (advisor) ; Chrtek, Jindřich (referee)
The presence of triploid individuals, whether hybrids arising from crosses of diploid and tetraploid plants, or spontaneously generated triploid hybrids diploid populations, is increasingly important in plant populations. However, the possible evolutionary role of the triploid hybrids is closely connected to the frequency of their occurrence, to their relative fitness (compared to parental cytotype) and fertility. As a model plant I choosed Tripleurospermum inodorum, in which a relatively frequent occurrence of triploid hybrids was documented in mixed populations of tetraploids and diploids. This annual plant achieves realy quick its reproductive maturity and is easily cultivated, making it an ideal model for cultivation and pollinating experiments. Compared to parental cytotypes, the triploid hybrids of T. inodorum take approximately the same (mostly mediated) fitness values. In vitro conditions were cultivated to measure of germination rates. Germination rate of triploid seeds was comparable to diploid parental cytotype. In the subsequent comparative cultivation, nearly 150 plant individuals (2x, 3x, 4x, and aneuploid cytotype) in the greenhouse showed that the triploids had intermedial values of their parental cytotypes or close to one of the parents. Thus, the vitality of the triploid plants is...

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