National Repository of Grey Literature 16 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Transgenerational effect of nutrient treatment on progeny of an apomitic plant
Vlk, Lukáš ; Mráz, Patrik (advisor) ; Skálová, Hana (referee)
Environmental conditions can influence epigenetic variability of clonal organisms. These environmentally induced changes have potential to persist in following generations. In theory, this transgenerational memory could allow clonal (and especially apomictic) plants to partly compensate reduced genetic variability and could enhance adaptative ability of apomictic populations. According to Muller's ratchet model, asexual organisms amass deleterious mutations, which could lead to their extinction. Possible transgenerational memory could partly compensate for this. It could also account for longtime survivorship of asexual organisms in environment. This thesis deals with transgenerational memory of triploid apomictic populations of Hieracium alpinum, with completely missing sexuality and thus genetically uniform offspring. Transgenerational effect in Hieracium alpinum was studied on clonal lineages originated from 5 populations (Norway, Austria, Bosnia and Herzegovina and Slovakia). Seeds were planted in cultivation experiment I in 3 treatments (control, added nutrients, added salicylic acid) and vegetative and generative traits were measured. Plants responded to nutrient addition but not to salicylic acid. Treatment with nutrient addition increased biomass, number of leaves and SLA (specific leaf...
The effect of Impatiens parviflora on native vegetation and factors affecting its spread
Florianová, Anna ; Münzbergová, Zuzana (advisor) ; Skálová, Hana (referee)
5 ABSTRACT Small balsam (Impatiens parviflora DC.) is one of the most widespread invasive plant species in central Europe. Nevertheless, the mechanisms of its invasion are still poorly understood. In this thesis I attempt to understand the impact of this species on native vegetation and the factors affecting its spread. The impact of small balsam on native vegetation was studied using a removal experiment on permanent plots in oak-hornbeam forests. Following small balsam removal in 2011, a slight increase in both number and abundances of native species was observed on the removal plots during 2012-2014 compared to the invaded plots. The species composition also significantly differed among invaded and removal plots. Species with high affinity to removal plots, i.e. species that are most restricted by small balsam invasion, were mostly species with small releasing height and early start of flowering. The factors affecting the spread of small balsam were studied between 2011 and 2014 on permanent transects in areas where it just started spreading. In each of 321 permanent plots, data on environmental conditions and on small balsam spread and performance were collected. The results show that small balsam seedlings spread mostly into areas with high soil moisture and low native species abundance, indicating...
Ecological and evolutionary consequences of polyploidization
Pavlíková, Zuzana ; Münzbergová, Zuzana (advisor) ; Skálová, Hana (referee)
Artificially synthesized neopolyploids are commonly used to distinguish the direct consequences of polyploidization for plants from those that were formed in polyploid line during subsequent evolution. Colchicine is usually used for induction of somatic polyploids. In this work I tested the possibility of making neopolyploids by using colchicine in three selected plant species. Succcess of neotetraploids was 9,3 % of the species Vicia cracca, 31,6 % of the species Centaurea phrygia and 33,3 % of the species Pimpinella saxifraga when using a 0,2% solution of colchicine and the effect of 12 hours. When extending the exposure time to 18 hours at the same concentration of colchicine in Vicia cracca the success of polyploidization was 100 % but mortality of individuals threated with colchicine was nearly 98 % (when exposed 12 hours it was only 43 %). Vicia cracca was grown to the second generation of neopolyploid plants, but part of the individuals was aneuploid and they were not phenotypically different from the natural tetraploids. Natural diploids, tetraploids and neotetraploids were compared in the size of stomata, rate of germination and relative growth rate. The size of stomata of diploids was significantly different from tetraploids and neotetraploids so it is possible to say that...
Impact of direct investments to development of communities
This bachelor thesis is focused on the theoretical effects of foreign direct investments onto development of communities. The main objective is to explore if and how the inflow of foreign investments influences the development of local municipality. To explore the objective, basic mathematical functions are used and the result tells us the amount of funds paid to the municipal budget from companies with direct foreign funding. Other results tell us how significant this income is for the chosen municipality. In the practical part of the thesis closely focuses on the impact of direct investment on the development of the towns of Klatovy, Pisek and Žďár nad Sázavou
Oppression symptoms in chldren's drawings - necessary knowledge for arts and crafts teachers
Skálová, Hana ; Klusák, Miroslav (referee) ; Jakubcová Hajdušková, Lucie (referee)
The work proceeds from the idea, that the knowledge of signs of emotional distress which can be found in children's drawings is important of arts and crafts teachers. There is more and more children living under stress and this is one of several possible ways of how to find them and provide them timely help. Children living under the stress (exposed to cruelty, too much demands, lack of emotional care etc.) show certain signs in their drawings and children psychologists can work with it. If this issue is taught in pedagogical faculties and in special lessons for arts and craft teachers, educators would be able to contact psychologists in time. The works is analysing available Czech psychological literature and determines whether someone has already worked with the issue, also introduces publications which might be useful for course of study of teachers, brings proposals of the idea of how to proceed in arts and crafts lessons, summarizes the problematic of CAN (syndrome of maltreated, neglected and abused child) and brings alarming tel. numbers of the Safety line. In the practical part, the teachers from kindergarten and grammar school prove that they are able to react to warning signs in children's drawings.
Phenotypic plasticity and its role in plant invasions
Hlavička, Matěj ; Herben, Tomáš (advisor) ; Skálová, Hana (referee)
Phenotypic plasticity is the ability of given genotype to produce different phenotypes as a response to environmental cues. Its capability of adaptive response draws an attention of invasion biologists. Although many studies have been performed, the true role of plasticity in an invasion process is still unclear. Comparative experiments suffer from several major constraints - insufficiency in revealing adaptive value of plastic response and uncertain linkage between plasticity and trait value. Further experiments could be focused to reaction norms of fitness instead of trait plasticity. Also, the interspecific interaction of plastic responses is definitely an underestimated mechanism and deserves far more attention than it does today. Possible implications of plant phenotypic plasticity in predicting future invasions require further reaserch.
Thermal requirements for plant development
Chuchvalcová, Lucie ; Skálová, Hana (advisor) ; Jarošík, Vojtěch (referee)
Plant development is strongly influenced by temperature. Other factors affect plant development to smaller extent. Plant development is affected by rate of enzymatic reactions which depend on temperature surrounding plant. Temperature and time are integrated into thermal time which is defined as sum of temperatures above temperature at which development ceases which is called base temperature. Cardinal temperature at which is the rate of plant development highest is called optimal temperature. When temperature exceeds optimum temperature rate of plant development, rate of development diminishes in higher rate than it increased between base and optimum temperature. Thermal time is mostly being used in agriculture for rate of development prediction, for optimizing crop yield, for prediction of particular developmental stage of weeds. There are also works that focus on wild plants. The easiest way to study temperature effect on plant development is to study leaf development. Rate of leaf appearance on the main stem and its reciprocal called phyllochron (duration separating appearance of two successive leaves) are plant development characteristics most frequently used. Use of thermal time instead of calendar days improved considerably prediction of plant phenological events. The goal of this bachelor thesis was...
Habitat requirements and competition between native and invasive Impatiens species
Čuda, Jan ; Skálová, Hana (advisor) ; Prach, Karel (referee)
Three of Impatiens species are widespread in the Czech republic, one is native, two of them invasive. Because all species occur in relatively similar habitats, the question is, whether the invasive species can negatively affect the native species, or even the original can can be displaced. The aim of the thesis was: (i) to compare habitat requirments of the Impatiens species, (ii) to determine if the coexistence of species is possible, (iii) to assess the impact of invasive species to the original species. The investigation was carried out using two sets of permanent plots in 5 localities. In the first set with a total of 84 plots (combinations of occurrence of the three species) site characteristics as tree cover, soil humidity, slope and bare land cover were directly measured and nutrient, light, humidity and soil reaction characteristic assessed using Ellenberg indicator values. The second set contained a total of 45 plots with one of the native-invasive congener pair being removed and the intact controls. Number, cover and height of the plants were assesed. The key enviromental factors determining distribution of the species were soil moisture for I. noli-tangere and I. parviflora, and tree cover for I. glandulifera and I. parviflora. Ellenberg indicator values had poor explanation value;...
Species diversity of meadows and pastures on small spatial scale
Bartoš, Michael ; Vojta, Jaroslav (advisor) ; Skálová, Hana (referee)
Grazing seems to be not only means of conserving species diversity of grasslands but also - in many cases - of its increasing. This thesis tries to find out the mechanisms of grazing that result in increased or decreased species diversity. The experiment was proceeded in Slupenec, a part of Český Krumlov, where horse pastures are situated. In order to compare grazing and mowing I collected phytosociological data from plots 1 x 1 mš. I also collected data about soil moisture, composition and pH in order to find out the main gradients in vegetation. The vegetation data from plots 20 x 20 cmš were collected before and after grazing on three pasturelands. In the chosen locality, higher level of plant species diversity have been proven on pastures in comparison with meadows. There is significantly higher percentage of plots contributing to the higher level of ß diversity on pastures than on meadows. At the same time the variability of vegetation was in most cases explained by the categorial variable pasture / meadow. Concerning selectivity of grazing, it has been proven that horses prefer grazing on species with greater cover abundance. The plots with lower rate of grazed species have got higher ß diversity. In terms of functional traits of plants, it has been proven that higher percentage of no-rosette...

National Repository of Grey Literature : 16 records found   1 - 10next  jump to record:
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6 Skálová, Helena
6 Skálová, Helena
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