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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

Revisão taxonomica e filogenia de Poecilanthe s.l. (Leguminosae, Papilionoideae, Brongniartieae) / A taxonomic revision and phylogeny of Poecilanthe s.l. (Leguminosae, Papilionoideae, Brongniartieae)

Meireles, Jose Eduardo de Carvalho 27 February 2007 (has links)
Orientador: Ana Maria Goulart de Azevedo Tozzi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T03:16:51Z (GMT). No. of bitstreams: 1 Meireles_JoseEduardodeCarvalho_M.pdf: 5457639 bytes, checksum: 2254e34efd86c3760ca5a245abf9eaf6 (MD5) Previous issue date: 2007 / Resumo: Poecilanthe (Leguminosae, Papilionoideae, Brongniartieae) é em gênero sul-americano que inclui atualmente dez espécies. A heterogeneidade morfológica e química encontrada em Poecilanthe dificulta sua circunscrição e coloca em dúvida sua monofilia. Além disso, limites interespecíficos imprecisos e falta de chave de identificação dificultam o reconhecimento das espécies. Este trabalho tem como objetivos testar a monofilia de Poecilanthe e estabelecer as relações entre suas espécies, bem como revisar a taxonomia do gênero. Para tanto, uma análise filogenética de máxima parcimônia baseada em caracteres morfológicos e seqüências de ITS/5.8S (nrDNA) foi realizada. Como subsídio para a análise cladística, foi feito um estudo sobre a morfologia das sementes e embriões de Poecilanthe, que resultou no reconhecimento de quatro padrões distintos de morfologia. Os resultados da filogenia mostram que Poecilanthe não é um gênero monofilético, sendo composto por três clados parafiléticos em relação à tribo. Estes três clados foram caracterizados morfologicamente e considerados como gêneros distintos. Poecilanthe é recircunscrito para incluir apenas as espécies extra-amazônicas (Poecilanthe s.s.), compreendendo então seis espécies. O gênero Amphiodon é restabelecido, e P. ovalifolia combinada neste. Um gênero novo é descrito para incluir P. amazonica e P. hostmannii. Cada um destes gêneros foi tratado taxonomicamente, constando em cada tratamento descrições, ilustrações e chave para a identificação das espécies / Abstract: The genus Poecilanthe (Leguminosae, Papilionoideae, Brongniartieae) currently comprises ten South-American species. The morphological and chemical diversity that is found within this genus renders its circumscription imprecise and brings Poecilanthe¿s monophyly into question. This work aims to test the monophyly of Poecilanthe and to revise the taxonomy of the genus. A parsimony analysis based on both morphological and ITS/5.8S data was carried out. In order to provide characters to the cladistic analysis, the morphology of the seeds and embryos of Poecilanthe was analyzed, and resulted in the identification of four different morphological patterns. The phylogeny does not support Poecilanthe as monophyletic, but resolves three different well-supported lineages that are paraphyletic with respect to the tribe. These clades are morphologically characterized and ranked at the generic level. Poecilanthe is recircumscribed to include the six extra-Amazonian species only. The genus Amphiodon is reinstated and P. ovalifolia is combined. Poecilante amazonica and P. hostmannii are segregated into a new genus. Each genus was revised and descriptions, illustrations and identification key for the species are presented. / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal
2

Ekologie hub, asociovaných s tlejícím dřevem v ekosystémech přirozených lesů / Ecology of deadwood-associated fungi in the ecosystems of nature-like forests

Zrůstová, Petra January 2014 (has links)
Dead wood plays an important role in forest ecosystems in the context of C dynamics, nutrient cycling, forest regeneration and biodiversity. Decaying wood sustains biodiversity by providing habitats and energy for fungi, bacteria, invertebrates, and many other organisms. Dead wood is resistant to decomposition and its decay is driven mainly by filamentous fungi. Community structure of wood- inhabiting fungi changes during decomposition, but the relationship between substrate quality and decomposer community is still poorly understood. This work studied fungal community composition with respect to tree species, stage of decay, volume and physico-chemical properties (such as pH, carbon and nitrogen content) of dead wood. Fungi were identified using next generation sequencing approaches - 454-pyrosequencing and Illumina MiSeq sequencing. Tree species, volume of dead wood (branches x logs) and stage of decay were the main variables affecting fungal community composition. Higher enzyme activities and content of fungal biomass indicate faster colonization of small branches than tree trunks by fungi. Fungal community composition, wood chemical properties and enzyme activities changed during decomposition. Both content of nitrogen and fungal biomass increased during decomposition. Enzyme activites peaked...
3

Charakterizace společenstva hub, podílejícího se na rozkladu opadu v jehličnatých lesích Národního parku Šumava / Charakterizace společenstva hub, podílejícího se na rozkladu opadu v jehličnatých lesích Národního parku Šumava

Žifčáková, Lucia January 2012 (has links)
Understanding of carbon cycling in coniferous forests that represent a large carbon sink is crucial for our understanding of natural processes under global climate change. Recognition of fungi as fundamental decomposers can contribute to this understanding. Fungi are able to decompose numbers of substrates and possess a variety of enzymes to do so In this study I present litter decomposing fungi in mountain spruce forest from national park Šumava. The aim of my thesis was to follow succession and community changes of fungi from the early stages of decomposition of Picea abies needles until degradation of organic matter in the organic horizon of the soil. This aim was accomplished partly by recording the extracellular enzyme production of fungi in different stages of decomposition from needles attached to the twigs of a fallen tree to a litter material in later stages of decomposition on the soil surface. In addition to testing of fungi on their natural substrata - needle litter, enzyme activities were also measured in laboratory agar cultures, which allow comparison of diverse fungi with different origins. Enzyme activities were aimed at enzymes decomposing cellulose and compounds found in litter. Although ecology of endophytic and saprothrophic fungi suggest differences in enzyme production, these...

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