>Magister Scientiae - MSc / Fi1sarium verticillioides is a very important mycotoxin-produeing fungus associated with maize. Fverticillioides produces a group of mycotoxins known as fumonisins under suitable environmental conditions. A series of studies was designed to provide information regarding some of the factors associated with the production offumonisin B1 (FB1) in maize patties and MYRO liquid medium. Our investigation together with previous studies have detailed the important influence of several factors on the production of fumonisins by F verticillioides strains. To understand why these strains are able to produce these toxins, an investigation into the complex interaction that occurs between biotic and abiotic parameters and their impact on fumonisin production was necessary. The results reflect the interacting factors and the intraspecific differences between strains, which may also be present in field conditions. The parameters that were varied under a predetermined set of culture conditions, included initial moisture content of maize patty cultures, temperature, initial pH and the addition of the fumonisin precursors, L-alanine and L-methionineto the cultures. Investigations into the three-way interactions of initial maize patty moisture content (30 ml water to 30g of maize), L-methionine (0.3 %) and temperature (25°C), resulted in the highest yield ofFB1 (5777.26 μgig) produced by MRC 4316. In contrast, MRC 826 was negatively affected, producing lower levels ofFB1 (3492.24 μg/g), compared to MRC 4316 at an initial moisture content (20 ml water to 30 g maize), L-methionine (0.3 %) and 25 °C. An American strain of F verticillioides MRC 7424 (= NRRL 13616), produced the highest levels of FB, (116 μg/ml), while the South African isolates, MRC 4316 and MRC 826, produced lower FB1 levels (93 and 62 μg/ml, respectively) in MYRO liquid medium. In general, FB1 production in maize patty cultures far exceeded levels obtained in liquid shake cultures. It appears that not only the ability of a particular strain of F. verticillioides, but the interaction of a variety of physiological and nutritional factors and the culture medium, are important in the production of FB,. Thus, variation of a single factor such as temperature under field conditions due to seasonal change, may therefore have a major effect on fomonisin production. A chain reaction may occur when changes in moisture, pH, etc. take place, which may influence fumonisin production further. Lyophilisation of fungal cultures proves to be an excellent method to preserve a wide range of fungi over long periods of time. It is, however, necessary to determine the viability of conidia stored in lyophilised vials at 4 ° Con a regular basis. At present, plate count methods remain the most valid technique for the detection of the viability of lyophilised conidia. Membrane-permeant nucleic acid-binding dyes (FUN-I) are viability stains that are relatively new flourescent probes for assessing the viability of metabolically active yeast cells. The purpose of this study was to microscopically determine the viability oflyophilised conidia of Fusarium and A lternaria species, using the yeast, Saccharomyces cerevisiae, as a control. FUN-1 viability stain was compared to two other staining methods, i.e. ethidium bromide (EB) and methylene blue (MB) and the viability of the conidia was compared to colony-forming units (CFU) on solid media as a control. For the purpose of determining or screening for percentage viability in a specific inoculum, results indicate that EB can be used in the case of lyophilised conidia, and MB in the case of freshly harvested conidia. Although FUN-I are recommended as a good way to determine the cell viability of a fungus, it needs relatively complicated procedures and has a time limit in which the stain can be used. The result of this study emphasize that the use of dyes to determine viability of lyophilised conidia require a critical definition of protocols for a specific fungal species, and that a good correlation with CFU needs to be demonstrated. The findings of this study could find useful applications in various studies on living and dead conidial populations. The diverse toxicological effects of fumonisins m animals and plants raised the possibility that fumonisins may also inhibit the growth of filamentous fungi. This study investigated the antifungal activity of FB1 to some h1sariu111 and other fungal species. The sensitivity of these fungi was tested by an agar-diffusion method on PDA plates. FB1 inhibited the myceliaJ growth of five of the nine fungi tested. The FB1-producing Fusarium species isolated from maize, i.e. F verticil/ioides, F glohosum and F proliferatum were resistant to FB1 even though a small inhibition zone at the highest FB1 concentration of 40mM was noted in the case of F. proliferatum. However, amongst two non-producing Fusarium spp. also isolated from maize, one (F subglutinans) was resistant and one (F graminearum) was sensitive. The most sensitive fungi tested were non-producing species not isolated from maize, i.e. A lternaria alternata, Botrytis cinerea and Penicillium expansum. The minimum inhibitory concentration ofFB1 ranged between 0.25-0.SmM for A. alternata, 1-SmM for P. expansum and B. cinerea and 5-1 OmM for F. graminearum, while the other fungi tested showed no sensitivity to FB1. This is the first report on the antifungal activity ofFB1 to filamentous fungi. Another study investigated the effect of FB1 on the germination of freshly harvested conidia of Fusarium and some other fungal species. The FB1 -producing F'usarium species isolated from maize, i. e. F vertici llioides, F. globosum and F. prolifer alum showed a decrease in germ tube length with an increase in FB1 concentrations. This indicated that these fungi can tolerate their own toxic metabolite to a ce11ain extent. However, amongst the two non-fumonisin producing Fi1sarium spp. examined, i.e. F. subglutinans and F. graminearum, isolated from maize, F. subglutinans was induced to genninate faster in the presence ofFB1 but soon developed stunted germ tubes, while F graminearum developed shorter germ tubes compared to the control cultures. The most sensitive fungi tested were species not isolated from maize, i.e. A. alternata, B. cinerea and P. expansum, which did not germinate at higher FB1 concentrations at all. Statistical analyses showed that the inhibiting effect of FB1 was highly significant (P <0.001). The conidial germination bioassay was more sensitive in the detection of the antifungal activity ofFB1 than the petri dish bioassay. The minimum inhibitory concentrations of FB1 for visible mycelial growth were closely comparable to those obtained from conidial germination. Results of these studies provide considerable information on the parameters affecting the production of FB1 and will be of great benefit in further studies focussing on fumonisin prodnction.

Thesis (M.Sc.)(Microbiology)--University of Pretoria, 2005. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Fusarium head blight (FHB) caused by Fusarium graminearum and Septoria tritici blotch (STB) caused by Septoria tritici are economically important wheat diseases in Ontario. Both reduce yield, FHB is associated with mycotoxin accumulation including deoxynivalenol (DON). Different F. graminearum chemotypes produce either DON/15-acetyldeoxynvialenol (ADON) or DON/3-ADON. The majority (97.5%) of F. graminearum isolates collected from commercial fields across Ontario were 15-ADON chemotype, the remaining were 3-ADON. In inoculated field experiments 3-ADON chemotypes were more aggressive and toxic compared with 15-ADON chemotypes as measured by FHB symptoms and DON content. In inoculated field experiments with a population derived from ‘RCATL33’ and ‘RC Strategy’ soft red winter wheat parents, genetic resistance was more effective than fungicide application at controlling FHB. Field trials with the hard red winter wheat population derived from ‘Maxine’ and ‘FTHP Redeemer’ parents revealed that STB and FHB phenotypic resistance had no negative impact on grain yield in the absence of disease.

Thesis (Ph.D.(Plant Pathology)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

Orientador: Edson Luiz Furtado / Banca: Nelson Sidnei Massola Junior / Banca: Erivaldo José Scaloppi Junior / Banca: César Junior Bueno / Banca: Eduardo Bagagli / Resumo: A heveicultura é de grande importância para o estado de São Paulo, especialmente, no Planalto Paulista. Representa uma das culturas florestais mais plantadas no país, tendo como principal objetivo, a extração do látex, que serve como fonte de matéria-prima para confecção de produtos para as indústrias pneumáticas, hospitalares, calçadistas, etc. Porém, pelo cultivo em caráter perene, o gênero Hevea sofre com o ataque de patógenos, principalmente, fungos. A fusariose, causada por Fusarium spp., é uma doença descrita recentemente, que afeta a casca das plantas adultas, interferindo na explotação de látex pelos produtores. Os sintomas surgem como trincas no caule, seguidos de necrose na casca, podendo causar o "secamento" do látex da árvore e, consequente, morte da planta. Mesmo sabendo-se da importância dessa doença afetando plantações de seringueira, há poucos estudos na literatura sobre os agentes causais, seu comportamento, resistência genética e outras formas de controle da doença. Portanto, no presente estudo objetivou-se caracterizar patogenicamente, morfologicamente e molecularmente 51 isolados de Fusarium spp., realizando, também, teste de resistência clonal e testando diferentes ingredientes ativos no controle "in vitro" dos isolados patogênicos. Para a caracterização morfológica dos esporos, foram avaliados a forma, o tamanho e o número de septos, os tipos de clamidósporos, a formação das fialides e conidiogênese dos microconídios e mesoconídios. A caracterização cult... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The rubber tree cultivation represents a great importance for the São Paulo state, especially, in the São Paulo uplands. It represents one of the most planted forest crops in the country, with the main objective, the latex extraction, which serves as a source of raw material for the manufacture of products for the pneumatic, hospital, footwear industries, etc. However, by the cultivation on a perennial basis, the genus Hevea suffers from pathogens attack, mainly, fungi. The fusariosis, caused by Fusarium spp., is a disease described recently that affects the bark of adult plants, interfering in the latex exploitation by the producers. The symptoms appear as cracks in the stem, followed by necrosis in the bark, which may cause the "tree drying" of the latex of the tree and, consequently, death of the plant. Even knowing about the importance of this disease affecting rubber tree plantations, there are few studies about the biology of the species, its behavior, genetic resistance and other ways of disease control. Therefore, the study aimed to perform studies about pathogenic, morphological and molecular characterization of 51 isolates of Fusarium spp., also performing a clonal resistance test and to study different active ingredients in the "in vitro" control of the pathogenic isolates. For the morphological characterization of the spores, were evaluated the shape, size and septa number, types of chlamydospores, the formation of phialides and conidiogenesis of the microconidia ... (Complete abstract click electronic access below) / Doutor

Submitted by NATÁLIA CAROLINA VIEIRA null (vieira_naty@hotmail.com) on 2016-03-21T18:33:32Z No. of bitstreams: 1 Dissertação de Mestrado - Natália Carolina Vieira.pdf: 4489683 bytes, checksum: bb278e0db97defa0e9b2982e4b2a0703 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-22T18:08:55Z (GMT) No. of bitstreams: 1 vieira_nc_me_araiq.pdf: 4489683 bytes, checksum: bb278e0db97defa0e9b2982e4b2a0703 (MD5) / Made available in DSpace on 2016-03-22T18:08:55Z (GMT). No. of bitstreams: 1 vieira_nc_me_araiq.pdf: 4489683 bytes, checksum: bb278e0db97defa0e9b2982e4b2a0703 (MD5) Previous issue date: 2016-03-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A cada ano vem crescendo a busca por novas fontes de produtos naturais, na qual os micro-organismos recebem uma grande atenção, sendo eles de extrema importância na descoberta de compostos bioativos e promissores a novos fármacos. Esse trabalho teve como foco o estudo de fungos filamentosos da rizosfera de Senna spectabilis. Foram testadas suas viabilidades e após esse processo, dez fungos foram escolhidos para esse trabalho e submetidos aos testes biológicos como citotóxico, anticolinesterásico e antifúngico e também foram obtidos seus perfis cromatográficos e químicos por CLAE-DAD e RMN, além da identificação filogenética. Após esses resultados iniciais, dois fungos foram escolhidos para desenvolver o método de desreplicação, sendo eles Fusarium solani e F. oxysporum. Esses fungos apresentaram atividade antifúngica contra C. cladosporioides e C. sphaerospermun e também apresentaram atividade anticolinesterásica, além disso, F. oxysporum apresentou também atividade antitumoral contra câncer do colorretal. Através das técnicas CG-EM, CLAE-EM, CLAE-EM/EM e RMN foram propostas estruturas moleculares interessantes para substâncias produzidas por esses micro-organismos, sendo que para o extrato de Fusarium solani foram identificados 12 metabólitos: ácido fumárico, ácido málico, tirosol, ácido p-hidroxibenzóico, ácido azelaico, ácido fusárico, (-)-ácido jasmônico/ácido (+)-7-iso-jasmônico, 10-hidroxicaptotecina, C-16-esfinganina, xestoaminol C, armilarina/armilaripina e beauvericina e para o extrato do fungo Fusarium oxysporum foram observados 14 metabólitos: ácido succínico, ácido phidroxibenzóico, ácido hexadecanóico, ácido octadecanóico, ácido fusárico e três de seus derivados, integracídeo C, fusagerina C/D, C-16-esfinganina, xextoaminol C, armilarina/armilaripina e beauvericina. Além desses compostos, outros 5 metabólitos comuns às espécies solani e oxysporum foram observados, mas não puderam ser estruturalmente caracterizados por CLAE-EM/EM, no entanto, suas massas moleculares já foram relatadas para espécies de Fusarium. / The search for new sources of natural products has been increasing to the rational exploration of microorganisms as great sources for the discovery of bioactives and promising compounds as well as new drugs. This work focused on the study of filamentous fungi, isolated from Senna spectabilis’s rhizosphere from which were tested its viabilities. Thereon, ten fungi were chosen for this work and were submitted to biological tests, such as cytotoxic, anticholinesterase and antifungal. In addition, their chemical profiles were obtained for HPLC and NMR, besides phylogenetic identification. Finally, two fungi were chosen to develop dereplication method, being them Fusarium solani and F. oxysporum.These fungi howed anticholinesterase activity and antifungal activity against C. cladosporioides and C. sphaerospermun. Additionally, F. oxysporum showed antitumor activity against colorectal cancer. Through the GC-MS, HPLC-MS, HPLC-MS/MS and NMR, we were able to obtained interesting molecular chemotypes for these microorganisms; for F. solani we identified 12 metabolites, fumaric acid, malic acid, tyrosol, p-hydroxybenzoic acid, azelaic acid, fusaric acid, (+)-7-iso-jasmonic acid/(-)-jasmonic acid, 10- hydroxycamptotecin, C16-sphinganine, xestoaminol C, armillarin/armillaripin and beauvericin and for F. oxysporum was observed 14 metabolites, succinic acid, phydroxybenzoic acid, hexadecanoic acid, octadecanoic acid, fusaric acid and its three derivatives, integracide C, fusagerin C/D, C-16-sphinganine, xestoaminol C, armillarin/armillaripin and beauvericin. Besides these compounds, others 5 metabolites common to both species (solani and oxysporum) couldn’t be structurally characterized thorough LC-MS/MS, but they were accounted in several Fusarium species.

Orientador: Carlos Frederico Wilcken / Banca: Antonio Batista Filho / Banca: Leonardo Rodrigues Barbosa / Resumo: A área de plantio de Eucalyptus no mundo tem aumentado nas últimas décadas. Em 2011 a área total de plantio de eucalipto no Brasil foi de 4.873.952 ha. Os insetos nativos são o principal problema nas plantações de eucalipto no Brasil. Entretanto,nos últimos anos novas pragas têm sido introduzidas e disseminadas causando perdas na cultura. O percevejo bronzeado Thaumastocoris peregrinus foi detectado pela primeira vez no Brasil em maio de 2008 em São Francisco de Assis, RS. Esse inseto afeta a produtividade dos plantios de eucalipto. As ninfas e os adultos se alimentam sugando as folhas, provocando pontos cloróticos nas folhas, que evoluem para um aspecto bronzeado. É necessário o estabelecimento e quantificação dos danos nas florestas de eucalipto bem como o desenvolvimento e implantação de um sistema integrado de controle para T. peregrinus. O desenvolvimento do controle microbiano como o uso de fungos entomopatogênicos, é uma opção de manejo da praga. As possibilidades são a utilização bioinseticidas comerciais existentes no mercado ou a obtenção de isolados nativos a partir da ocorrência de epizootias naturais no campo, para posterior desenvolvimento de novos inseticidas biológicos. Diante do problema que essa praga vem causando em plantios de eucalipto e das limitadas alternativas para seu controle o presente trabalho teve os seguintes objetivos: Obter isolados de fungos entomopatogênicos a partir de indivíduos de T. peregrinus mortos coletados em campo; selecionar isolados e realizar sua caracterização biológica (velocidade de crescimento e aspecto geral da colônia... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The area of Eucalyptus plantations in the world has increased in recent decades. In 2011 the total area of eucalyptus plantations in Brazil was 4.873.952 ha. The native insects are a major problem in eucalyptus plantations in Brazil, but in recent years, new pests have been introduced and causing widespread crop losses. In May, 2008,Thaumastocoris peregrinuswas detected first time in Brazil, in São Francisco de Assis, State of Rio Grande do Sul. This pest reduces and affects the productivity of eucalyptus plantations. Nymphs and adults feed by sucking the leaves, causing chlorotic spots, which develop inbronzed look. The development of microbial control using microrganisms, as entomopathogenic fungi, as an option. Testsevaluatingcommercial bioinsecticides and isolating native fungi speciesfrom the natural epizootics in the field,are an important tool for its control. Nowadays there is a few control alternatives for the problem caused by this pest in eucalyptus plantations. The present work aimed to obtain isolates of entomopathogenic fungi from dead individuals of T. peregrinus collected in field; selecting isolatesand evaluated them considering characteristics of biology (growth rate and general appearance of the colony) morphology (size and shape of spores and the presence / absence of specialized structures) and molecular; verify the sensitivity of fungi isolate against potential insecticides used to eucalyptus bronze bug control; evaluate colonization of fungi isolated when inoculated directly into the bronze bug using scanning electron microscopy. Many fungi were isolated, but for practical purposes only two were chosen... (Complete abstract click electronic access below) / Mestre

Orientador: Ian Castro-Gamboa / Banca: Isabele Rodrigues Nascimento / Banca: Flávia Talarico Saia / Resumo: A cada ano vem crescendo a busca por novas fontes de produtos naturais, na qual os micr o - organismos recebem uma grande atenção, sendo eles de extrema importância na descoberta de compostos bioativos e promissores a novos fármacos. Esse trabalho teve como foco o estudo de fungos filamentosos da rizo sfera de Senna spectabilis . F oram testadas suas viabilid ad es e a pós esse processo, dez fungos foram escolhidos para esse trabalho e submetidos a os testes biológicos como citotóxico, anti colinesterásico e antifúngico e t ambém foram obtidos seus perfis cromatográficos e químicos por CLAE - DAD e RMN, além da identificação filogenética. A pós esses resultados iniciais, dois fungos foram escolhidos para desenvolver o método de desreplicação, sendo eles Fusarium solani e F . oxysporum . Esses fungos apresentaram atividade antifúngica contra C. cladosporioides e C. sphaerospermun e também apresentaram atividade anticolinesterásica, além disso, F. oxysporum apresentou também atividade antitumoral contra câncer do colorretal. Através das téc n icas CG - EM, CLAE - EM, CLAE - EM/EM e RMN foram propostas estruturas moleculares interessantes para substâncias produzidas por e sses micro - organismos, sendo que para o extrato de Fusarium solani foram identificados 1 2 metabólitos: ácido fumárico, ácido málico, tirosol, ácido p - hidroxibenzóico, ácido azelaico, ácido fusárico, ( - ) - ácido jasmônico/ácido (+) - 7 - iso - jasmônico, 10 - hidroxicaptotecina, C - 16 - esfinganina, xestoaminol C, armilarina/armilaripina e beauvericina e para o extrato d o fungo Fusarium oxysporum foram observados 14 metabólitos: ácido succínico, ácido p - hidroxibenzóico, ácido hexadecanó i co, ácido octadecanóico, ácido fusárico e três de seus derivados, integracídeo C, fusagerina C/D, C - 16 - esfinganina, xextoaminol C, armila rina/armilaripina e beauver i cina . Além desses... / Abstract: T he search for new sources of natural products has been increasing to the rational exploration of microorganisms as great sources for the discovery of bioactives and promising compounds as well as new drugs. This work focused on the study of filamentous fungi, isolated from Senna spectabilis's rhizosphere from which were tested its viabilities. Thereon, ten fungi were chosen for this work and were s ubmitted to biological tests, such as cytotoxic, anticholinesterase and antifungal. In addition, their chemical profiles were obtained for HPLC and NMR, besides phylogenetic identification. Finally, tw o fungi were chosen to develop dereplication method, being them Fusarium solani and F . oxysporum. Th ese fungi howed anticholinesterase activity and antifungal activity aga in st C. cladosporioides and C. sphaerospermun . Additionally, F. oxysporum showed antitumor activity against colorectal cancer. Through the GC - MS, HPLC - MS, HPLC - MS/MS and NMR, we were able to obtained interesting molecular chem o types for these microorganisms; for F. solani we identified 12 metabolites, fumaric acid, malic acid, tyrosol, p - hydroxybenzoic acid, azelaic acid, fusaric acid, (+) - 7 - iso - jasmonic acid/( - ) - jasmonic acid, 10 - hydroxycamptotecin, C16 - sphinganine, xestoaminol C, armillarin/armillaripin and beauvericin and for F. oxysporum was observed 14 metabolites, succinic acid, p - hydroxybenzoic acid, hexadecanoic acid, octadecanoic acid, fusaric acid and its three derivatives, integracide C, fusagerin C/D, C - 16 - sphinganine, xestoaminol C, armillarin/armillaripin and beauvericin . Besides these compounds, others 5 metabolites common to both species ( solani and ox y sporum ) couldn't be structurally characterized thorough LC - MS/MS, but they were accounted in several Fusarium species. / Mestre

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-23T15:24:11Z No. of bitstreams: 1 Susan Satie Tsuji.pdf: 801633 bytes, checksum: f830ce7fba5b8d7999b6897bb595841a (MD5) / Made available in DSpace on 2017-03-23T15:24:11Z (GMT). No. of bitstreams: 1 Susan Satie Tsuji.pdf: 801633 bytes, checksum: f830ce7fba5b8d7999b6897bb595841a (MD5) Previous issue date: 2012-02-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Fusarium guttiforme (sin. Fusarium subglutinans f. sp. ananas) is the causal agent of fusariosis on pineapple (Ananas comosus). This disease, considered the most important to this crop, has the exudation of gum as the most common symptom. Most of the published studies focus on the evaluation of the resistance of pineapple varieties against F. guttiforme. The estimative of genetic diversity in Fusarium populations is fundamental to understand the population structure, the movement of pathogen genetic material between producing regions, as well as understanding the processes that lead to resistance against pesticides and overcoming genetics resistance of pineapple cultivars. This fungus, which can be found in most regions of the country, does not have a known teleomorph and belongs to the Gibberella fujikuroi species complex, a group with heterogeneous characteristics. This study aimed: a) to obtain a collection of Fusarium isolates associated with pineapple fusariosis in the country; b) to reconstruct the phylogeny of Fusarium isolates that causes fusariosis on pineapple from Northeast and Southeast regions; c) to test the pathogenicity of isolates. DNA sequences of translation elongation fator 1-α (tef1) and calmodulin (cmd) were analyzed, and the history of the alleles was inferred by phylogenetic methods. Tef1 gene sequences were used to estimate the number of haplotypes from isolates collected in different regions. It was observed that the F. guttiforme is the causal agent of fusariosis on pineapple in Brazil, and the tef1 gene allowed a better infraspecific group distinction than cmd gene. / A fusariose do abacaxizeiro (Ananas comosus) tem como agente etiológico o fungo Fusarium guttiforme (sin. Fusarium subglutinans f. sp. ananas). Esta doença, considerada a mais importante da cultura, tem como sintoma a exsudação de goma, sendo conhecida também como gomose ou resinose fúngica. A maior parte dos estudos publicados avaliou a resistência de variedades de abacaxizeiro a F. guttiforme. A estimativa da diversidade genética em populações de Fusarium é fundamental para o entendimento da estrutura populacional, do movimento de material genético do patógeno entre regiões produtoras através da disseminação do mesmo, bem como do entendimento dos processos que levam a resistência a defensivos e superação da resistência genética de cultivares de abacaxi. Esse fungo, que se encontra disseminado por todas as regiões produtoras do país, ainda não possui o teleomorfo conhecido e pertence ao complexo Gibberella fujikuroi, um grupo com características heterogêneas. O presente trabalho teve como objetivos: a) obter uma coleção de isolados de Fusarium associados à fusariose do abacaxizeiro no país; b) avaliar a filogenia de isolados de Fusarium das regiões Nordeste e Sudeste; c) testar a patogenicidade dos isolados obtidos. Foram analisadas sequências parciais de DNA dos genes fator de elongação 1-α (tef1) e calmodulina (cmd), inferindo-se a história dos alelos através de métodos filogenéticos. Sequências parciais do gene tef1 foram utilizadas para estimar o número de haplótipos dos isolados coletados em diferentes regiões produtoras. Observou-se que a espécie F. guttiforme é o agente causal da gomose do abacaxizeiro no Brasil e que o gene tef1 possibilitou uma melhor distinção de grupos infraespecíficos que o gene cmd.

Fusarium verticillioides (= Fusarium moniliforme) a common fungal contaminant of maize throughout the world has been associated with diseases in both man and animals. The structure of the fumonisins, a family of structurally related mycotoxins isolated from cultures associated with the high incidence of human oesophageal cancer in the Transkei region in South Africa and with equine leucoencephalomalacia, a neurological disorder in horses and donkeys, has been established. The main mycotoxin, fumonisin B1 consists of the diester formed by the C(14) and C(15) hydroxyl groups of (2S,3S,5R,10R,12S,14S,15R,16R)-2- amino-12,16-dimethyleicosane-3,10,14,15-pentaol with the Si carboxy group of propane- 1,2,3-tricarboxylic acid. A comparison of the structures of the 28 known fumonisins reveals that they share a common structural motif for the C(11)-C(20) unit, and probably also the same stereochemistry for the 4 stereogenic centres present in this unit. Disconnection of the C(9)–C(10) bond in a retrosynthetic analysis of the fumonisins C20 backbone (C19 in the fumonisin C series)identifies (3S,5S,6R,7R)-3,7-dimethylundecane-1,5,6-triol as a common building block for the synthesis of any of the fumonisins. In the dissertation the retrosynthetic analysis of this 3,7-dimethylundecane-1,5,6-triol building block identifies (3S,4R,5R)-5-methylnonane-1,3,4-triol as a viable target which in turn could be derived from a simple starting material trans-4-hexen-3-one. Key reactions identified to realise the required transformations leading to the identified target included kinetic enzymatic resolution of the racemic alcohol obtained from trans-4-hexen-3-one, and a pivotal role for both the [2,3]-Wittig rearrangement and the use of Sharpless asymmetric epoxidation methodology as these reactions generated the requisite stereogenic centres present in (3S,4R,5R)-5-methylnonane-3,4-diol. In this manner a synthetic route from trans-4-hexen-3- one to (2R,3R,4R,5R,6E)-4-(benzyloxy)-2,3-epoxy-5-methylnon-6-en-1-ol using appropriate functional group transformations and protective group strategies, with complete stereochemical control, were developed in this work. Alternative strategies to overcome problems encountered during the synthesis are presented for future work. The conversion of the 4-(benzyloxy)-2,3-epoxy-5-methylnon-6-en-1-ol intermediate to the protected 5- methylnonane-1,3,4-triol target could not be carried out due to time constraints and material shortages. / Dissertation (MSc)--University of Pretoria, 2011. / Chemistry / unrestricted