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Ecological determinants of plant clonal growth
Martincová, Nina ; Weiser, Martin (advisor) ; Latzel, Vít (referee)
The aim of this study is to provide a further insight into influence of environment on clonal plants. The study focuses particularly on effects of fertilization level and light availability on production and growth of clonal organs. Three experiments were carried out within the study, targeted to elicit influence of these environmental conditions or clonal interactions on six species of clonal plants. Interspecies dependencies on these conditions was compared, regarding habitat occurrence of these species. A comparison was made also between species producing rhizomes and stolons. The experiments revealed that five of six studied species show significant relationship among at least one environmental condition and parameters of clonal reproduction. Most of the species showed higher elongation and production of clonal organs in relation to fertilization level. On the contrary, only three species reacted significantly to the light availability level by alternation of at least one parameter of clonal reproduction and the light availability level affected each species differently. A strong influence on production and elongation of clonal organs had also a size of a plant. There was not found significant difference in influence of environmental conditions on clonal reproduction among plant families. It...
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Clonal integration of Agrostis stolonifera in heterogeneous soil environment
Duchoslavová, Jana ; Weiser, Martin (advisor) ; Klimešová, Jitka (referee)
Clonal plants may be able to cope with spatial heterogeneity due to the physiological integration of ramets. Previous studies demonstrated that benefits of clonal integration increase with patch contrast between individual ramets. However, the same magnitude of contrast may be perceived differently in rich and poor environments. According to the theoretical work of Caraco and Kelly (1991), I expected these benefits to be the greatest in overall poor conditions and high between-patch contrast. To test this hypothesis, I conducted experiments with pairs of ramets of a stoloniferous grass, Agrostis stolonifera, grown in variously nutrient rich conditions. The experiment with pairs of ramet of similar developmental age showed only very weak effect of integration on growth of ramets, although integration significantly improved survival of ramets and also affected root-shoot ratio of ramets. Nevertheless, there were considerable benefits of integration in the experiment with developmentally older mother ramets and their daughter ramets. Contrary to the predictions, the benefits of integration were bigger in rich conditions and they decreased with increasing between-patch contrast. In addition, effect of integration on root-shoot ratio of ramets was opposite to the expected specialization for acquisition...
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Phenotypic plasticity and cytotypes of \kur{Agrostis stolonifera} in the Czech Republic
KUBEŠOVÁ, Magdalena
Presence and range of phenotypic plasticity in the Agrostis stolonifera polyploid complex (Poaceae) was studied in the territory of the Czech Republic. Plants were cultivated under different experimental conditions. Stomatal size of different Agrostis stolonifera cytotypes was measured. Flow cytometry was applied for genome size estimation. Ploidy levels were determined for more than 150 samples of Agrostis stolonifera as well as several specimens of Agrostis canina, A. capillaris, A. gigantea, A. rupestris and A. vinealis. Absolute DNA content was estimated in all studied species. Isozyme analysis was used to test the possibility of the hybrid origin of pentaploid individuals of Agrostis stolonifera species.
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