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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

Biodiversity, ecology and taxonomy of saprobic fungi on palm fronds

鄭遠技, Yanna. January 2001 (has links)
published_or_final_version / Ecology and Biodiversity / Doctoral / Doctor of Philosophy
2

The graminaceous rusts and smuts of Kansas

Haard, Richard Thomas. January 1963 (has links)
Call number: LD2668 .T4 1963 H32 / Master of Science
3

The genus Leptographium : a critical taxonomic analysis

Jacobs, Karin 18 December 2006 (has links)
Leptographium have been known since the early part of the 20th Century and include of many species causing blue stain of timber. Among these species are several species known or believed to be involved in causing diseases of trees. Leptographium spp. occur mainly on conifers and many species are recognized as anamorphs of Ophiostoma. Similar to Ophiostoma, Leptographium spp. are closely associated with insects. Their morphology thus reflects this association, and they thus have upright conidiophores with slimy masses that are produced in beetle galleries. Leptographium spp. are morphologically very similar to each other and this makes their accurate identification difficult. The first part of this thesis, presents dichotomous, as well as synoptic keys for the identification of these species. These keys are supported by comprehensive descriptions accompanied by both photographs and line drawings. The second part of this thesis. deals with several key taxonomic questions pertaining to Leptographium. Chapter one represents a phylogenetic study of the majority of species in Leptographium. Morphological characters were coded and analyzed. The results of the molecular and the morphological analyses are compared to determine whether any morphological characters might be used to infer phylogeny. The results indicate that morphology does not infer phylogenetic relatedness. Chapter two represents a comparison between Leptographium abietinum and L. engelmannii. These species are morphologically similar, and various authors have suggested that they are synonyms. Based on morphology, L. engelmanni was synonomised with L. abietinum. Furthermore, examination of various atypical isolates led to the description of the new species, L. hughesii. In chapter three, Ophiostoma europhioides, O. piceaperdum and Ceratocystis pseudoeurophioides are compared. These species have Leptographium anamorphs and are morphologically identical. Both O. europhioides and C. pseudoeurophioides are synonymised with O. piceaperdum, and a name is provided for the anamorph of O. piceaperdum. Chapter four represents a re-evaluation of Phialocepha/a phycomyces. The inconspicuous collarettes, characteristic of this fungus, are unlike the deep¬seated collarettes of the type species of Phialocepha/a (P. dimorphospora). Scanning and transmission electron microscopy revealed that conidiogenesis in P. phycomyces is phialidic, placing this species among other Phialocephala spp. However, P. phycomyces is able to tolerate high concentrations of cycloheximide, characteristic of Leptographium spp. DNA analysis indicates that this species does not belong in either Phialocepha/a or Leptographium. A new genus Kendrickiella is described to accommodate this species. In chapter five, a new species of Leptographium, L. eucalyptophilum, is described. This species is unique in that it occurs on Eucalyptus, which is an unusual host for this species. In addition, this species is one of several described from tropical regions and it is apparently adapted to this habitat. Chapter six represents a critical re-evaluation of isolates identified as L. procerum. Morphological comparison of these isolates revealed that L. procerum sensu lato, represents more than one taxon. From this study, three new species of Leptographium were described. These are L. alethinum, L. pityophilum and L. euphyes. These species can easily be distinguished from L. procerum s. str. and their incorrect identification is probably as a result of their shared habitat. In chapter seven, I describe an additional three species of Leptographium. Like most other Leptographium spp., these were isolated from conifers. The first of these, L. pineti, originates from Indonesia. The other two species is found in high elevation sites in Eastern North America. These are L. abicolens and L. peucophilum. These species are unique in that they are associated with the conifer swift moth, which is an unusual insect associate of Leptographium. Chapter eighth presents a description of a new species of Leptographium from Russia. This species, L. sibiricum, is associated with staining and mortality in siberian fir (Abies sibirica). The role of the fungus in the disease complex is still unknown, and awaits further study. This thesis represents a comprehensive review of all known, as well as newly described species. It should greatly facilitate plant pathologists and mycologists in the identification of Leptographium spp. This should lead to extensive pathogenicity tests, to determine the economic impact of species in this genus as blue-stain fungi and pathogens. It is my sincere wish that it will renew interest in this group of fungi, and will lead to the description of many more species in this genus. / Thesis (PhD)--University of Pretoria, 2006. / Microbiology and Plant Pathology / Unrestricted
4

Biodiversity, systematics and ecology of nematode-trapping fungi from Hong Kong

Aung, Swe. January 2009 (has links)
published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy
5

The diversity of root fungi associated with Erica species occurring in the Albany Centre of Endemism

Bizabani, Christine January 2015 (has links)
South Africa has the highest species diversity of ericaceous plants belonging to the Erica genus. There are over 850 identified species in the Cape Floral Region. The Albany Centre of Endemism (ACOE) is located within this region and is a hotspot of diversity consisting of various plant genera. The success of Erica plants is ubiquitously attributed to mycorrhizal relationships they engage in with a diverse group of fungi. This symbiosis is known as the ericoid mycorrhizal (ERM) association. The overall aim of this study was to establish the diversity of root fungi associated with Erica plants using morphological, molecular and 454 pyrosequencing techniques. Six Erica species were identified using leaf and flower morphology according to taxonomic keys. The identified plants were Erica cerinthoides, Erica demissa, Erica chamissonis, Erica glumiflora, Erica caffra and Erica nemorosa. Roots from sampled plants were stained and examined microscopically to determine their mycorrhizal status. Ericoid mycorrhizal associations together with dark septate endophyte (DSE) structures and hyphae that did not form any specific structure were observed in all the roots. In addition arbuscular mycorrhizal (AM) structures in the form of vesicles were detected in E. glumiflora and E. cerinthoides. In order to identify the culturable fungi associated with the respective hosts, sterilised roots were placed on various culture media for cultivation. Thereafter isolated fungi were morphologically classified into 67 morphotypes. These were mostly sterile and darkly pigmented. Non-sporulating mycelia of variable colouration such as white, cream-yellowish, beige, green and brown were also observed. Further identification was carried out using molecular techniques. DNA was extracted separately from pure cultures and amplified using ITS1 and ITS4 primers in a polymerase chain reaction (PCR). Thereafter sequencing and Basic Local Alignment Search Tool (BLAST) were used to identify the isolates to generic level. The fungi were taxonomically classified into 54 operational taxonomic units and 94 percent were Ascomycetes and Helotiales was the dominant order. Unclassified Helotiales with affinities to fungi currently identified as Epacrid root fungus was common in all hosts. Other isolates that were identified included Oidiodendron, Meliniomyces, Phialocephala, Cadophora, Lachnum, Leohumicola Cryptosporiopsis, Chaetomium, Acremonium and Epicoccum species. Basidiomycetes were represented by two OTUs belonging to the genus Mycena. Four OTUs comprised fungi that had no significant alignments in the reference databases. Direct root DNA extraction together with 454 pyrosequencing was used to detect the diversity of culturable and unculturable fungi associated with the identified hosts. The ITS2 region was targeted for sequencing. Although Ascomycetes remained the dominant phyla, Basidiomycetes were also detected in all host plants. Glomeromycota was present in E. caffra and E. cerinthoides. Helotiales was dominant in all Erica plants with the exception of E. cerinthoides and E. chamissonis which were dominated by the order Chaetothyriales. The OTUs identified to genus level included Epacris pulchella root fungus, Oidiodendron cf. maius, Acremonium implicatum, Leohumicola, Lachnum, Capronia and Mycena species. Culture-based techniques and pyrosequencing detected similar fungal composition comprising Ascomycetes, while, pyrosequencing was able to detect Glomeromycetes and Basidiomycetes.
6

A study of certain members of the South African xylariaceae, with reference to the use of cultural characters in classification

Martin, Philip Michael Dunlop January 1961 (has links)
[Summary] Sixty-three species, drawn from the genera Rosellinia Hypoxylon, Nummularia, Daldinia, Penzigia and Xylaria, are studied in order to determine whether any correlation exists between various characters of the perfect stage and characters connected with the mycelium in artificial culture that might be used to supplement the existing classification of the Xylariaceae. An examination is made of the morphological and anatomical characters of several stromal types and a statistical method of evaluating differences in ascospore dimension between samples of closely related species is described. Cultural work shows that :- a) Each species group, based primarily on similarity of stromal form, has a characteristic set of cultural characters. b) Members within a Species group can usually be distinguished clearly in culture. The use of cultural characters as an additional criterion in classification is therefore recommended.
7

The Taxonomy and ecology of Arbuscular Mycorrhizal fungi (AMF) in agroforestry systems in Malawi

Jefwa, Joyce Mnyazi 11 August 2008 (has links)
Please read the abstract in the section, 00front, of this document / Thesis (PhD)--University of Pretoria, 2008. / Plant Science / unrestricted
8

Fungos anemófilos na cidade de Botucatu e sua correlação com sensibilização em portadores de doenças alérgicas respiratórias / Airborne fungi and their correlation with sensitization in patients with respiratory allergic diseases from the town of Botucatu

Silva, Elaine Gagete Miranda da 05 May 2005 (has links)
Introdução: Fungos são alérgenos cuja importância nas doenças alérgicas respiratórias é subestimada por falta de extratos alergênicos adequados para diagnóstico, quer através de testes cutâneos, quer através de dosagem de IgE específica. Botucatu possui características próprias por se localizar numa \"cuesta\" e possuir vegetação variada que cobre grande parte da cidade. A partir das plantas os fungos ganham o ar através da esporulação podendo ser inalados e sensibilizar pacientes com alergias respiratórias. Este trabalho se propõe a estudar quais os fungos mais prevalentes em Botucatu e a taxa de sensibilização dos principais gêneros entre os portadores de asma e rinite procedentes dessa região. Casuística e Métodos: Foi desenvolvido um aparelho caça esporos para a captura dos mesmos em quatro pontos da cidade. Foram feitas cinco coletas/ponto/semana durante um ano para contagem e identificação das UFC (unidades formadoras de colônias). Foram selecionados pacientes de Botucatu e região com asma e rinite, nos quais se aplicou testes de puntura para os principais alérgenos, incluindo onze diferentes fungos. Foram também realizados testes intradérmicos com extratos de fungos nos pacientes cujo teste de puntura ao fungo em questão tenha sido negativo. Resultados: Foram identificados 67 gêneros sendo os mais prevalentes: Cladosporium, Epicoccum, Levedura, Aspergillus, Helminthosporium, Nigrospora, Monilia, Fusarium, Hyalodendrum, Penicillium, Curvularia, Humicola, Alternaria, Trichoderma e Sphaerosporium. Foram selecionados 207 pacientes dos quais 118 (57%) apresentaram pelo menos um teste positivo a fungo. O teste intradérmico foi responsável por 88% do diagnóstico de sensibilização A dosagem de IgE específica mostrou baixa sensibilidade (4%). Os fungos mais sensibilizantes foram: Aspergillus, Neurospora, Candida, Penicillium e Cladosporium. Observou-se maior positividade a fungos no grupo de asma grave, sendo que Aspergillus, Neurospora e Candida foram mais prevalentes nesse grupo. Encontrou-se associação positiva entre pacientes com asma atendidos em Pronto-Socorros durante o ano estudado e o total de UFC nesse período. Conclusões: Os fungos mais prevalentes no planeta são também encontrados em Botucatu, embora haja fungos característicos dessa região; a sensibilização a fungos é expressiva na população estudada e guarda relação com maior gravidade da asma; o teste intradérmico foi o melhor meio diagnóstico para sensibilização a fungos / Purpose: Fungi are allergens whose importance has been underestimated due to the absence of reliable extracts for the diagnosis of sensitization in vivo or in vitro. Botucatu has unique characteristics because of its location on a \"cuesta\" and its varied vegetation which cover a large area of the city. The fungi reach the air from the plants through sporulation and they can be inhaled and sensitize patients with allergic diseases. Here we studied the most prevalent fungi in the air of Botucatu and the rate of sensitization to the main fungi genus among patients with asthma and rhinitis. Methods: We developed a spore trap to catch the spores from the air in four points in the city. Five collections were taken weekly during a whole year. Colony forming units (CFU) were counted and the fungi on Petri dishes were classified. Patients with asthma and rhinitis have been selected and submitted to prick tests with the main allergens including eleven different types of fungi. Intradermal tests with fungi extract were also performed in the patients whose prick test to these fungi had been negative. Results: Sixty-seven genus of fungi have been identified and the more prevalent were: Cladosporium, Epicoccum, yeast, Aspergillus, Helminthosporium, Nigrospora, Monilia, Fusarium, Hyalodendrum, Penicillium, Curvularia, Humicola, Alternaria, Trichoderma and Sphaerosporium. Two hundred and seven patients have been selected and 118 (57%) have been at least one positive test to fungus. Intradermal test made the diagnosis in 88% of all diagnostics of sensitization, whereas \"in vitro\" specific IgE had low sensibility (4%). The more sensitizer fungi were: Aspergillus, Neurospora, Candida, Penicillium and Cladosporium. There was a significant correlation between severe asthma and fungi sensitization and the fungi more prevalent in that group of patient were: Aspergillus, Neurospora and Candida. Moreover, there was a positive correlation between the number of asthmatic patients attended in Emergencies and the total of CFU in the study period. Conclusion: We recognize in the air fungi specific to Botucatu although the most prevalent fungi are the same found in other places in the world; the fungi sensitization among patients with allergic respiratory diseases is meaningful and correlated with asthma severity; the intradermal test was the best mean to diagnose fungi sensitization
9

Fungos anemófilos na cidade de Botucatu e sua correlação com sensibilização em portadores de doenças alérgicas respiratórias / Airborne fungi and their correlation with sensitization in patients with respiratory allergic diseases from the town of Botucatu

Elaine Gagete Miranda da Silva 05 May 2005 (has links)
Introdução: Fungos são alérgenos cuja importância nas doenças alérgicas respiratórias é subestimada por falta de extratos alergênicos adequados para diagnóstico, quer através de testes cutâneos, quer através de dosagem de IgE específica. Botucatu possui características próprias por se localizar numa \"cuesta\" e possuir vegetação variada que cobre grande parte da cidade. A partir das plantas os fungos ganham o ar através da esporulação podendo ser inalados e sensibilizar pacientes com alergias respiratórias. Este trabalho se propõe a estudar quais os fungos mais prevalentes em Botucatu e a taxa de sensibilização dos principais gêneros entre os portadores de asma e rinite procedentes dessa região. Casuística e Métodos: Foi desenvolvido um aparelho caça esporos para a captura dos mesmos em quatro pontos da cidade. Foram feitas cinco coletas/ponto/semana durante um ano para contagem e identificação das UFC (unidades formadoras de colônias). Foram selecionados pacientes de Botucatu e região com asma e rinite, nos quais se aplicou testes de puntura para os principais alérgenos, incluindo onze diferentes fungos. Foram também realizados testes intradérmicos com extratos de fungos nos pacientes cujo teste de puntura ao fungo em questão tenha sido negativo. Resultados: Foram identificados 67 gêneros sendo os mais prevalentes: Cladosporium, Epicoccum, Levedura, Aspergillus, Helminthosporium, Nigrospora, Monilia, Fusarium, Hyalodendrum, Penicillium, Curvularia, Humicola, Alternaria, Trichoderma e Sphaerosporium. Foram selecionados 207 pacientes dos quais 118 (57%) apresentaram pelo menos um teste positivo a fungo. O teste intradérmico foi responsável por 88% do diagnóstico de sensibilização A dosagem de IgE específica mostrou baixa sensibilidade (4%). Os fungos mais sensibilizantes foram: Aspergillus, Neurospora, Candida, Penicillium e Cladosporium. Observou-se maior positividade a fungos no grupo de asma grave, sendo que Aspergillus, Neurospora e Candida foram mais prevalentes nesse grupo. Encontrou-se associação positiva entre pacientes com asma atendidos em Pronto-Socorros durante o ano estudado e o total de UFC nesse período. Conclusões: Os fungos mais prevalentes no planeta são também encontrados em Botucatu, embora haja fungos característicos dessa região; a sensibilização a fungos é expressiva na população estudada e guarda relação com maior gravidade da asma; o teste intradérmico foi o melhor meio diagnóstico para sensibilização a fungos / Purpose: Fungi are allergens whose importance has been underestimated due to the absence of reliable extracts for the diagnosis of sensitization in vivo or in vitro. Botucatu has unique characteristics because of its location on a \"cuesta\" and its varied vegetation which cover a large area of the city. The fungi reach the air from the plants through sporulation and they can be inhaled and sensitize patients with allergic diseases. Here we studied the most prevalent fungi in the air of Botucatu and the rate of sensitization to the main fungi genus among patients with asthma and rhinitis. Methods: We developed a spore trap to catch the spores from the air in four points in the city. Five collections were taken weekly during a whole year. Colony forming units (CFU) were counted and the fungi on Petri dishes were classified. Patients with asthma and rhinitis have been selected and submitted to prick tests with the main allergens including eleven different types of fungi. Intradermal tests with fungi extract were also performed in the patients whose prick test to these fungi had been negative. Results: Sixty-seven genus of fungi have been identified and the more prevalent were: Cladosporium, Epicoccum, yeast, Aspergillus, Helminthosporium, Nigrospora, Monilia, Fusarium, Hyalodendrum, Penicillium, Curvularia, Humicola, Alternaria, Trichoderma and Sphaerosporium. Two hundred and seven patients have been selected and 118 (57%) have been at least one positive test to fungus. Intradermal test made the diagnosis in 88% of all diagnostics of sensitization, whereas \"in vitro\" specific IgE had low sensibility (4%). The more sensitizer fungi were: Aspergillus, Neurospora, Candida, Penicillium and Cladosporium. There was a significant correlation between severe asthma and fungi sensitization and the fungi more prevalent in that group of patient were: Aspergillus, Neurospora and Candida. Moreover, there was a positive correlation between the number of asthmatic patients attended in Emergencies and the total of CFU in the study period. Conclusion: We recognize in the air fungi specific to Botucatu although the most prevalent fungi are the same found in other places in the world; the fungi sensitization among patients with allergic respiratory diseases is meaningful and correlated with asthma severity; the intradermal test was the best mean to diagnose fungi sensitization
10

Onicomicoses causadas por fungos filamentosos não dermatófitos / Onychomycosis caused by filamentous fungi non-dermatophytes

Souza, Simone Felizardo Rocha de 08 February 2008 (has links)
INTRODUÇÃO: Onicomicose, infecção das unhas por fungo é a mais freqüente das doenças ungueais, constituindo aproximadamente metade de todas as alterações ungueais. Pode ser causada por dermatófitos, leveduras ou fungos filamentosos não dermatófitos. OBJETIVO: Caracterizar as onicomicoses causadas por fungos filamentosos não dermatófitos. (1) Verificar, dentre as suspeitas clínicas de onicomicose, qual a freqüência da recuperação de fungos,(2) Verificar, dentre as suspeitas clínicas de onicomicose, quais as espécies de fungos recuperadas, (3) Verificar, dentre o total das espécies identificadas, qual a freqüência das espécies de fungos filamentosos não dermatófitos. MÉTODOS: Duzentos e cinco indivíduos com suspeita clínica de onicomicose foram estudados no período de dezembro de 2003 a novembro de 2004, por meio de exames micológicos diretos e cultura para fungos. RESULTADOS: O diagnóstico de onicomicose foi estabelecido, pelo exame micológico direto, em 170 indivíduos. O diagnóstico etiológico foi estabelecido pela cultura para fungos. Dentre os 107 agentes identificados, os dermatófitos foram identificados em 78,52% (N=84), as leveduras em 13,08% (N=14) e os FFND em 8,40% (N=9) das vezes. CONCLUSÃO: É necessário que se estabeleça o diagnóstico etiológico dos casos de onicomicoses, já que os fungos filamentosos não dermatófitos ocorrem com freqüência considerável e são indistinguíveis daquelas por dermatófitos. / INTRODUCTION: Onychomycosis, a nail fungus infection is the most frequent nail disease, constituting about half of all nail disorder. It can be caused by dermatophytes, yeasts and non- dermatophytes filamentous fungi. OBJECTIVE: Characterize the onychomycosis caused by filamentous fungi non- dermatophytes. (1) Verify after a clinical suspicion of onychomycosis, which are the frequency of fungi recovery, (2) examine, after a clinical suspicion of onychomycosis, which species of fungi are recovered, (3) Checking, among the total of identified species , which are the frequency of the species of filamentous fungi not dermatophytes. METHODS: Two hundred and five patients with clinical suspicion of onychomycosis were studied in the period from December 2003 to November 2004, through direct mycological examination and culture for fungus. RESULTS: The diagnosis of onychomycosis has been established by direct mycological examination, in 170 individuals. The etiological diagnosis was established by the culture for fungus. Among the 107 persons identified, the dermatophytes were recovered in 78.52% (N = 84), the yeast in 13.08% (N = 14) and filamentous fungi non- dermatophytes in 8,40% (N = 9). CONCLUSION: It is necessary to establish the etiological diagnosis of the cases of onychomycosis, as filamentous fungi non- dermatophytes occur often than ever considered and are its clinic features are indistinguishable from those of the dermatophytes.

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