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.

La maladie de la tache noire affecte les fruits d’ananas mature, les rendant impropre à la consommation. Actuellement, aucune méthode de contrôle n'est disponible pour cette maladie. Une meilleure connaissance du pathosystème est nécessaire pour trouver des moyens de lutte efficaces.Des entretiens et échantillonnages menés auprès de producteurs durant l’hiver austral révèlent une prévalence de la maladie de 74%. Les champignons pathogènes appartiennent à plusieurs espèces : Fusarium ananatum (72% des isolats), Talaromyces stollii (21%), F. oxysporum (6%) et F. proliferatum (1%). Leur potentiel toxinogène a été déterminer, Les champignons du genre Fusarium ont produit des mycotoxines identifiées comme les fumonisines FB1, FB2 et la beauvericine. Sur un milieu de culture ananas, une concentration en beauvericine de 34959 µg kg-1 a été mesurée pour l’espèce F. proliferatum.Une méthode d’inoculation de Fusarium ananatum directement dans le parenchyme a permis de décrire la réponse du biochimique du fruit. La voie des phénylpropanoïdes est sollicitée, particulièrement avec l’élicitation du caffeoylisocitrate et du coumaroylisocitrate dans la zone infectée. Une comparaison des profils métaboliques montre que la réponse du fruit à une inoculation est plus importante chez le cultivar résistant ‘MD-2’ que chez le cultivar sensible ‘Queen’. La majorité des métabolites élicités par l’attaque sont déjà présents dans les fruits sains mature de la variété résistante. Le potentiel antifongique des composés phénoliques à était évalué. Les acides coumarique, caféoylquinique et férulique inhibent la croissance du mycélium à des concentrations similaires à celle trouvées dans les fruits infectés.Une approche par imagerie a permis de décrire l’anatomie des fruits des deux cultivars et notamment la fusion imparfaite des sépales et bractée chez ‘Queen’. Les nectaires et les parois carpellaires jouent un rôle clef dans le processus d'infection et de colonisation de Fusarium ananatum. / Fruiltet core rot (FCR) disease affects the fruits of mature pineapples. Current disease controls are not available. A deeper knowledge of the pathosystem is needed to find an effective means of control FCR.A diagnostic survey conducted with producers during the southern winter revealed a prevalence of the disease of 74%. Pathogenic fungi belong to several species: Fusarium ananatum (72% isolates), Talaromyces stollii (21%), F. oxysporum (6%) and F. proliferatum (1%). Their toxinogenic potential was determined. Fusarium fungi produced mycotoxins identified as fumonisins FB1, FB2 and beauvericin. On a pineapple culture medium, a concentration of beauvericine of 34959 μg kg-1 was measured for the species F. proliferatum.A method of inoculating Fusarium ananatum directly into the parenchyma allowed to describe the biochemical response of the fruit. The phenylpropanoids pathway is involved, particularly with the elicitation of caffeoylisocitrate and coumaroylisocitrate in the infected zone. A comparison of the metabolic profiles shows that the response to inoculation of resistant cultivar 'MD-2' is higher than in the sensitive cultivar 'Queen'. Most of the metabolites elicited by the attack are already present in healthy mature fruits of the resistant variety. The antifungal potential of the phenolic compounds was evaluated. Coumaric, caffeoylquinic and ferulic acids inhibit mycelial growth at concentrations similar to those found in infected fruits.An imaging approach allowed to describe the anatomy of the fruits of the two cultivars, to identify the key roles played by nectaries and carpel margins in the infection and colonization process of Fusarium ananatum.