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Plant strategies in belowground competition - insight through game theory
Smyčka, Jan ; Weiser, Martin (advisor) ; Šmilauer, Petr (referee)
In recent decades, it was shown that belowground competition for some plants may take form of the tragedy of the commons (TOC). In these plants, the competing neighbours invest more in root systems than would be appropriate for optimal nutrient uptake for the group and also more than they do when grown alone. However, there is also strong evidence that other species do not follow TOC, and tailor their root system to best nutrient exploitation irrespectively of competitor presence. The root investment strategy of these plants should correspond to the ideal free distribution (IFD). In my thesis I focus on two aspects: I use game theoretical models to explore, whether those strategies can coexist within species and also whether different species can coexist if they have different strategy. From this model I draw predictions, which I test by meta-analysis. Using Agrostis stolonifera as a model, I test assumptions on nutrient and neighbour perception, which underlie TOC and IFD models. I show that according to mathematical models, those two strategies can coexist in different species in a community, but cannot coexist within a species. Within a species, the TOC strategy should always dominate, once it appears. This can be extrapolated to macroevolutionary scale - once TOC occurs in certain clade, it should...
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Characterization of programmed cell death during lyzigenous aerenchyma formation
Lenochová, Zuzana ; Votrubová, Olga (advisor) ; Čiamporová, Milada (referee) ; Kummerová, Marie (referee)
Abstract____________________________________________________________________ 2 ABSTRACT: Zea mays is generally considered to be a plant with inducible lysigenous aerenchyma formation. The degradation of some cortical cells is triggered by environmental conditions, usually in the form of stress (submergence etc.). These cells die in a process that shows signs characteristic for programmed cell death, such as nuclear DNA fragmentation or apoptotic ultrastructural alterations. Aerenchyma formed in primary roots of thirteen examined maize accessions, irrespective of cultivation conditions. The aerenchyma fraction correlated with the root length, not with its age. The dependence of aerenchyma formation on the presence of this phytohormone was proved by using an inhibitor of ethylene synthesis (AOA). It was found out that the aerenchyma formation depended on light conditions and that the lysigenous intercellulars intercellular spaces colocalized with areas with cells with characteristically fragmented nuclear DNA (TUNEL-positive nuclei). In experiments using the TUNEL reaction it was necessary to determine new dilution of the enzymatic mixture for the examined plant material. Only the observation of surface planes of free-hand root sections was considered relevant in both TUNEL-TMR and TUNEL-AP assays. TUNEL-AP...
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Diversity and ecology of endophytic fungi in different parts of pants.
Kovaříčková, Adéla ; Prášil, Karel (advisor) ; Kolařík, Miroslav (referee)
Even though endophytic fungi have been studied intensively in the past years, little attention has been payed to endophytic colonisation of a whole plant. The search part of this work is about the differences in diversity and ecology of endophytes within whole plants, whose single parts represent qualitatively different environments for growth of endophytic fungi. The main difference is between the colonisation of systemic endophytes of grasses from family Clavicipitaceae and the colonisation of taxonomically heterogenous group of non-systemic endophytes. A systemic endophyte colonizes all above-ground organs of grass, while a non-systemic endophytes form only local infections, and their species composition in specific plant parts differs. The practical part of this work encompasses the pilot study of species diversity of endophytic fungi from woody parts (branches, stems and roots) of an elm tree (Ulmus laevis). There are differences in the frequency of colonisation among samples cultivated on agar plates, and also in diversity of isolated fungal genera.
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Stanovení množství posklizňových zbytků v osevním postupu v podmínkách hospodaření se živočišnou výrobou
Barteska, Tomáš
The dissertation focuses on issue of a post-harvest residues in the crop rotation. The paper describes methodology of setting up the experiment, measurements, collection and analysis of samples. Also available is a characteristics and climatic conditions of the experimental locality. The amount of post-harvest residues were followed up for 3 crops (winter wheat after alfalfa, winter wheat after maize and spring barley after sugar beet) for three variants of tillage and three sampling depths. From these selected the most post-harvest residues 24.98 t.ha-1, was left by winter wheat grown after alfalfa sown variant with direct seeding. The smallest amount of 13.02 t.ha-1 was measured for spring barley after method of minimization. Option of plowing for wheat after alfalfa and wheat after corn reached was measured by average of 17.5 t.ha-1. Average amount of underground biomass of all crops without distinction in processing variations was resulted at the depth of 0 - 0.15 m amount of 10.03 t.ha-1. At a depth of 0.15 to 0.30 m, it was 2.84 t.ha-1 and at a depth of 0.30 to 0.45 m - 2.40 t.ha-1. The total amount of post-harvest residues (underground biomass + straw stubble) Winter wheat was grown after alfalfa - 21.25 t.ha-1, winter wheat after corn - 18.77 t.ha-1 and spring barley after sugar beat - 13.45 t.ha-1. The results of dissertation showed a significant difference according the results listed in the literature sources. This could be due to the influence of the year, which was extremely profitable and may also be influenced by the selection of representative localities, because the sample taken represents only a small portion of the total area
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Adventitious sprouting of short-lived plants in natural populations
MALÍKOVÁ, Lenka
Disturbance is one of most important selective factor causing removal of plant biomass. Man-made habitats are characterized by strong and unpredictable disturbances, providing bare soil surface colonized by plants with short life cycle. Populations of the short-lived plants are, however, vulnerable to the strong disturbance removing all stem parts with reserve axillary meristems in the case it occurs before plant flowering and fruiting. Nevertheless, 2 % of annual and 14 % of biennial plants are able to overcome meristem limitation by adventititous sprouting from hypocotyle or/and roots. This thesis is composed of four original studies describing the occurrence of adventitious sprouting in natural populations of 22 monocarpic weeds of Central Europe and one species in Indonesia. The studied phenomenon was analyzed in relation to various environmental factors and plant traits in the field and in experimental conditions.
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Roots of terrorism.
CARVA, Pavel
Terrorism is a phenomenon of our everyday life and fight against terrorism touches all of us. The objective of the thesis is to approach historical evolution of terrorism, its historical and present roots and also the influence of terrorism on the whole society. In the theoretical part of the work basic characteristics of terrorism were elaborated, fundamental concepts were defined and forces that are involved in the fight against terrorism were described. Historical stages of evolution of terrorism were described and compared in the practical part. On the basis of the evaluation the first stage of historical evolution of terrorism was clearly defined and acts and deeds that happened during this stage and could be perceived as historical roots of terrorism were described. Then the most significant present roots of terrorism were described together with development of the number of terrorist attacks and their consequences. The thesis also focuses on terrorism as a possible threat for citizens of the Czech Republic. Further on the work describes measures taken in relation with terrorism and restrictions resulting from them for the whole society. The thesis results may be used as another source for workers of the Integrated Rescue System and Crisis Management that provides summary information related to terrorism and restrictions resulting from the fight against it for our society.
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Energy reserves in \kur{Lythrum salicaria} L. over time
KUNC, Dušan
Lythrum salicaria is an invasive plant in North America. The study is focused on carbohydrate reserves (especially starch) in below-ground plant organs of the named species. These energy sources are considered as possible contributors of invasive behaviour both in short and long time periods. Another question is whether these storages can be influenced by other factors. These ideas were tested in common garden experiments.
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