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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Aislamiento de hongos filamentosos con actividades ligninolíticas en Calamagrostis nitidula Pilger

Laura Huanaco, Janet January 2008 (has links)
Se realizó el aislamiento de hongos filamentosos en una planta forrajera del país Calamagrostis nitidula Pilger, hierba anual que pertenece a la familia Poaceae. Las Poaceas presentan un 14 % de lignina, este polímero tiene un alto grado de resistencia al ataque microbiano y es considerado un componente anti-calidad por su impacto negativo en la disponibilidad nutricional de la planta, debido a que la lignina disminuye la accesibilidad de los polisacáridos estructurales y otros componentes de la pared celular. El aislamiento de los hongos se realizó en medio mínimo Czapeck teniendo a la lignina como única fuente de carbono en un 0.2% estos caldos fueron inoculados con fracciones de Calamagrostis nitidula Pilger, posteriormente estos hongos fueron aislados en Agar papa dextrosa (APD) e identificados según sus características morfológicas y microscópicas. Se aislaron e identificaron los siguientes géneros: Alternaria, Ulocladium, Trichoderma, Cephalosporium, Fusarium, Helicomyces, Mucor y Aspergillus, este último fue identificado como Aspergillus melleus Yukawa y resultó ser la única cepa capaz de degradar la lignina. Se determinó cualitativamente y cuantitativamente la capacidad de degradación de la lignina inoculando cada cepa en tubos con caldo Czapeck, con 0.2% lignina y 1% glucosa, la coloración inicial de este caldo fue de color café, al cabo de 7 días se leyó al espectrofotómetro en una longitud de onda de 560 nm. De todas las cepas fúngicas aisladas únicamente la cepa PD5F identificada como Aspergillus melleus Yukawa fue capaz de virar el medio del color café a amarillo (prueba cualitativa) degradando un 80 % de la lignina (prueba cuantitativa). / --- Fungi were isolated from a forage grass Calamagrostis nitidula Pilger, an annual plant belonging to the Poaceae family. Members of the Poaceae family have 14 per cent of lignin, a polymer highly resistant to the microbial attack, and considered as an anti-quality component by its negative impact to the nutritional readiness. Lignin diminishes the accessibility to the structural polysaccharides and other components of the cell wall. The isolation of the fungi was carried out in Czapeck minimum medium; containing 0.2 % lignin as the only carbon source, these broths were inoculated with fractions of Calamagrostis nitidula Pilger. Then fungi were isolated in the culture medium APD and identified according to their morphological and microscopic characteristics. The following genus were isolated and identified: Alternaria, Ulocladium, Trichoderma, Cephalosporium, Helicomyces Mucor and Aspergillus. The last one was identified as Aspergillus melleus Yukawa because was able to degrade the lignin. The capacity of lignin degradation was determined qualitatively and quantitative inoculating each strain in test tubes containing Czapeck broth, lignin 0.2% and glucose to 1%, the starting color of this broth was brown, after 15 days, it was read to the spectrophotometer at 560 nm. Of all the strains isolated, only the strain PD5F identified as Aspergillus melleus Yukawa was able to turn the medium starting color (brown) to yellow (qualitative test), degrading 80% of the lignin (quantitative test). / Tesis
2

Aislamiento de hongos filamentosos con actividades ligninolíticas en Calamagrostis nitidula Pilger

Laura Huanaco, Janet January 2008 (has links)
Se realizó el aislamiento de hongos filamentosos en una planta forrajera del país Calamagrostis nitidula Pilger, hierba anual que pertenece a la familia Poaceae. Las Poaceas presentan un 14 % de lignina, este polímero tiene un alto grado de resistencia al ataque microbiano y es considerado un componente anti-calidad por su impacto negativo en la disponibilidad nutricional de la planta, debido a que la lignina disminuye la accesibilidad de los polisacáridos estructurales y otros componentes de la pared celular. El aislamiento de los hongos se realizó en medio mínimo Czapeck teniendo a la lignina como única fuente de carbono en un 0.2% estos caldos fueron inoculados con fracciones de Calamagrostis nitidula Pilger, posteriormente estos hongos fueron aislados en Agar papa dextrosa (APD) e identificados según sus características morfológicas y microscópicas. Se aislaron e identificaron los siguientes géneros: Alternaria, Ulocladium, Trichoderma, Cephalosporium, Fusarium, Helicomyces, Mucor y Aspergillus, este último fue identificado como Aspergillus melleus Yukawa y resultó ser la única cepa capaz de degradar la lignina. Se determinó cualitativamente y cuantitativamente la capacidad de degradación de la lignina inoculando cada cepa en tubos con caldo Czapeck, con 0.2% lignina y 1% glucosa, la coloración inicial de este caldo fue de color café, al cabo de 7 días se leyó al espectrofotómetro en una longitud de onda de 560 nm. De todas las cepas fúngicas aisladas únicamente la cepa PD5F identificada como Aspergillus melleus Yukawa fue capaz de virar el medio del color café a amarillo (prueba cualitativa) degradando un 80 % de la lignina (prueba cuantitativa). / Fungi were isolated from a forage grass Calamagrostis nitidula Pilger, an annual plant belonging to the Poaceae family. Members of the Poaceae family have 14 per cent of lignin, a polymer highly resistant to the microbial attack, and considered as an anti-quality component by its negative impact to the nutritional readiness. Lignin diminishes the accessibility to the structural polysaccharides and other components of the cell wall. The isolation of the fungi was carried out in Czapeck minimum medium; containing 0.2 % lignin as the only carbon source, these broths were inoculated with fractions of Calamagrostis nitidula Pilger. Then fungi were isolated in the culture medium APD and identified according to their morphological and microscopic characteristics. The following genus were isolated and identified: Alternaria, Ulocladium, Trichoderma, Cephalosporium, Helicomyces Mucor and Aspergillus. The last one was identified as Aspergillus melleus Yukawa because was able to degrade the lignin. The capacity of lignin degradation was determined qualitatively and quantitative inoculating each strain in test tubes containing Czapeck broth, lignin 0.2% and glucose to 1%, the starting color of this broth was brown, after 15 days, it was read to the spectrophotometer at 560 nm. Of all the strains isolated, only the strain PD5F identified as Aspergillus melleus Yukawa was able to turn the medium starting color (brown) to yellow (qualitative test), degrading 80% of the lignin (quantitative test).
3

Využití vybrané terénní metody pro stanovení mineralizace půdních organických látek v extrémních klimatických podmínkách

Alba Mejía, Jhonny Edison January 2011 (has links)
No description available.
4

Variabilita \kur{Calamagrostis phragmitoides} v ČR a srovnání s morfologicky podobnými druhy / The variability of \kur{Calamagrostis phragmitoides} in the Czech Republic and its comparison with morphologically similar species

SCHAABOVÁ, Veronika January 2015 (has links)
Calamagrostis phragmitoides belongs to taxonomically complex C. purpurea aggregate with circumpolar distribution area. The relations between morphologically similar taxa of this aggregate are not clear. Populations of C. purpurea agg. from Central Europe, Scandinavia and Siberia (including one plant from the North America) were genetically studied (cpDNA, ITS, ploidy level by FCM). Allozyme and morfological variability of populations C. phragmitoides and morphologically similar C. canescens was also studied in the Czech Republic. This study was supported by grant SGA PrF JU in 2014.
5

Mezidruhové interakce v mokřadním společenstvu v závislosti na vodním režimu: dlouhodobý test stress-gradient hypotézy / Interspecific interactions in wetland communities in dependence on water regime: long-term test of stress-gradient hypothesis

Růžičková, Kateřina January 2016 (has links)
The Stress-gradient hypothesis predicates a change of interspecies relations from negative to positive according to the stress gradient. The basic assumption is that the presence of one species (the facilitator) makes the growth of other species easier. In this study was determined based on the 5years experiment, whether the interspecies interactions (i.e. the importance of facilitation and competition) changes according to the hydrological conditions. Three wetland species (Calamagrostis canescens, Carex elongata and Deschampsia cespitosa) were planted in experimental pots with the presence and absence of the dominant species (Carex elata). The hydrological gradient (= the stress gradient) was simulated by three types of hydrological conditions: dry, fluctuating and wet. The success of the species within the specific conditions was correlated with the fitness-related characteristics of the plants including the biomass, the number of ramets and the height of the plants. Following hypotheses were tested: i) at a low intensity of stress (with the wet treatment), the C. elata represents a competitor for other species. On the other hand, at a high intensity of stress (with the dry treatment), the C. elata represents a facilitator, making it easier to the other coexisting species to grow. This presumption was confirmed only with the D. cespitosa, which was more successful under dry treatment with the presence of a dominant species, which facilitated it. With the other two species the change of interspecific relations was not observed and the relationships remained negative. Furthermore the results showed, that in the dry treatment with the presence of a dominant species, there was a lower intensity of competition among the coexisting species. The experiment showed, that the interactions of particular species with dominant species can vary according to the stress gradient. The hydrological gradient also influences the character and intensity of interactions among the species.
6

Evaluating Establishment of Native Rhizomatous Grass Species for Reclaiming Sites in Southern Alberta with Limited Topsoil

McGregor, Laura Elizabeth 26 April 2013 (has links)
Anthropogenic disturbances to Alberta’s landscape have resulted in the widespread removal of indigenous plant communities. Steep slopes and limited topsoil are often barriers when trying to reestablish vegetation; however, native rhizomatous grass species have a number of traits that make them ideally suited to revegetate challenging sites. A field study evaluated the establishment of three species of native perennial rhizomatous grasses (Calamagrostis canadensis, Calamovilfa longifolia, and Hierochloe odorata) from three propagation methods. Initial results suggest that these species were able to establish and survive on these sites despite poor soil conditions. Establishment was poor in seeded plots (24.1%), but improved with root cuttings (75.9%) and nursery-grown plugs (96.3%). The use of vegetative establishment methods could increase the successful application of native grass species, and encourage their use in landscape design and restoration projects. / Thank you to Imperial Oil and the Glenbow Ranch Park Foundation for providing financial and material support for this project.
7

Rozdílné mikrobiální aktivity v rhizosféře trav Festuca ovina a Calamagrostis epigejos

Filipová, Lenka January 2014 (has links)
The diploma thesis "Different microbial activity in the rhizosphere of grasses Festuca ovina and Calamagrostis epigejos" deals with the issue of climate change and eutrophication and their impact on the stability of rare habitats, specifically dry acidophilous grasslands in the Podyjí national park. The aim of the thesis is to study and collect the available sources about the issue of the interaction of soil microorganisms and plant roots in exceptional and protected dry grassland ecosystems, which are colonized by aggressive expansion of Calamagrostis epigejos, thereby compromising their integrity and stability. This issue is still not fully understood. Review of literature in the thesis describes the explanation of the most significant part of the issue - the nutrient cycling in ecosystems, C: N ratio, the role of microorganisms in the soil, and the importance of microbial processes in the rhizosphere and in grassland ecosystems generally. In the experimental part the hypothesis - that drought stress and eutrophication causes changes in the plant - microorganisms - soil system, which result in destabilization of the system, by an increase in leakage of nitrate and ammonium ions from the soil, and in changes in the quantity and quality of underground and aboveground biomass of Festuca ovina -- was confirmed.
8

Effet de l'aération d'appoint, de la saison et de l'espèce de macrophytes dans le traitement d'un effluent piscicole par marais artificiel

Ouellet-Plamondon, Claudiane January 2004 (has links)
No description available.
9

Obnova druhově bohatých luk na výsypkách po těžbě uhlí, vliv růyných technik a velikosti obnovované plochy / Obnova druhově bohatých luk na výsypkách po těžbě uhlí, vliv růyných technik a velikosti obnovované plochy

Kolářová, Petra January 2014 (has links)
Common problems and characteristics of sites affected by the mining are land occupation, pollution, land degradation, hydrologic changes and landscape change what belong to the major environmental problems in many countries. Despite the regulation prescribed by the Mining Act which brought significant progress in post mining land reclamation, emphasise mostly in recovery of production capability of landscape, many recent studies state it may not be so effective in restoration of diversity and ecosystem services. In order to properly assess newer approaches in spoil heaps recultivation our research is focused on the restoration of species rich meadows using near-nature methods, specifically the transfer of turves and seeds-containing hay transfer supported by management (mowing and mowing with mulching). Additionally, the research is focused on influence of the plot size on restoration success and on effect of management on soil development. Both of the applied near-nature methods of species rich meadow recultivation are effective in species provisioning and thus succession acceleration. More successful is the method of transferred turves where it was possible to establish more than 60% of the species from the donor site. The species richness on sites and its spreading is dependent on implemented...
10

Přispívá vodní stres a mezidruhová konkurence k funkční konvergenci nebo divergenci vlastností mokřadních rostlin? / Does water stress and interspecific competition contribute to the functional divergence or convergence of wetland plant species?

Műnichová, Radka January 2017 (has links)
This diploma thesis is based on the experiment which took 5 years. In 52 plastic containers were planted four species wetland plants; two species of grasses (Calamagrostis canescens and Deschampsia cespitosa) and two species of sedges (Carex elata and Carex elongata). Three types of water regime were set up with: high, low and fluctuating water level, where the high and low level of water took turns after one year. One year before the data collection the strongest competitor Carex elata was cut out. For the evaluation of the role of water level (environmental stress) and removal of the dominant (competition) we selected two functional trait indicators: specific leaf area (SLA) and leaf dry matter content (LDMC). SLA is an indicator of resource strategies, competitiveness and efficiency of light photosynthesis. Species with high SLA are usually better competitors for light, but tolerate harder the environmental stress. LDMC reflects a plants investment in persistent leaf structures and therefore in nutrient retention. A significant effect of water regime on LDMC was observed in the species Deschampsia cespitosa that had higher average values of LDMC in dry water regime, which is indicating higher investment into persistent leaf structures. And the effect of the dominant removal on SLA, where the values of SLA in the containers without removed dominant were higher. Increased SLA implies increased intensity of competition for light. My diploma thesis supported that specific leaf area and leafdry matter content are important functional indicators different types of stress conditions in wetland communities.

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