FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A qualidade do pescado à um tÃpico de grande interesse dos produtores do setor pesqueiro, tendo em vista o aumento nos mercados internacionais para produtos frescos de pescado. Esse trabalho teve como objetivo comparar a eficiÃncia do Ãcido ascÃrbico e do metabissulfito de sÃdio sobre o tempo de conservaÃÃo e inibiÃÃo de melanose de camarÃes acondicionados em gelo. Foram adquiridos camarÃes vivos da espÃcie Litopenaeus vannamei cultivados em fazendas do Estado do CearÃ. Imediatamente apÃs a despesca, os camarÃes foram imersos em soluÃÃes de quatro diferentes concentraÃÃes de Ãcido ascÃrbico a 200, 300, 400 e 500 ppm e de metabissulfito de sÃdio a 6%. Posteriormente, os crustÃceos submetidos aos diferentes tratamentos foram estocados em gelo por vinte dias. A cada 48 horas foram retiradas amostras para avaliaÃÃo do grau de melanose, dos caracteres sensoriais, anÃlises microbiolÃgicas, determinaÃÃo da trimetilamina (TMA), das bases volÃteis totais (BVT), do valor de K e o acompanhamento do pH. Os tratamentos com Ãcido ascÃrbico mostraram serem Ãteis no controle da melanose. No entanto, o tratamento com metabissulfito de sÃdio foi mais eficiente na prevenÃÃo da melanose. Quanto à avaliaÃÃo do quesito controle de qualidade do camarÃo armazenado em gelo, nÃo houve diferenÃa entre os tratamentos. Foi verificado que a partir do 14 dia os camarÃes estocados em gelo mostraram sinais de putrefaÃÃo. Conclui-se que nÃo à viÃvel economicamente a utilizaÃÃo do Ãcido ascÃrbico no controle da melanose em camarÃes, visto que poderia haver necessidade de concentraÃÃes mais elevadas do produto nos tratamentos de imersÃo para evitar o surgimento de manchas pretas. / Quality of fisheries products is a subject of great interest among producers since the international market for fresh products is expanding. The objective of the present study was to compare the efficiency of ascorbic acid and sodium metabisulfite in conserving product quality for long periods and inhibiting black spot occurrence in shrimp kept in ice. Live shrimp, Litopenaeus vannamei, grown in a shrimp farm at Ceara State, Brazil, were used in the experiment. Immediately after capture, the shrimp were immersed in four different concentrations of ascorbic acid (200, 300, 400 and 500 ppm) and also in 6% sodium metabisulfite. After that, all the shrimp from the five treatments were transferred to ice and kept for 20 days. Every 48 hours samples from the five treatments were taken in order to analyze the level of black spot occurrence, sensorial characteristics, trimethylamine, total volatile basic, K value and pH value. The ascorbic acid showed good results in preventing black spot, although sodium metabissulfite was more efficient in preventing it. When quality control was evaluated from shrimp kept in ice, no significant different was observed among the treatments. After 16 days kept in ice, all shrimp showed some level of decay. Although the ascorbic acid showed good results in preventing black spot occurrence, it is not economically viable to use it for shrimp, since the product is costly and requires high concentration to prevent black spot.

O Brasil é o maior produtor e exportador de suco de laranja, sendo esta uma das mais importantes atividades econômicas para o país. Os frutos são afetados pela mancha preta dos citros, causada por Guignardia citricarpa, que deprecia comercialmente os frutos, provoca queda prematura e eleva o custo de produção. Medidas alternativas ao controle químico clássico vêm sendo estudadas e, neste contexto, insere-se a indução de resistência. O presente trabalho teve como objetivo avaliar os efeitos in vitro da quitosana e radiação UV-C sobre o crescimento micelial, germinação e formação de apressórios por G. citricarpa e a ação destes agentes abióticos no controle da doença em laranjas pós-colheita, sob armazenamento ambiente e refrigerado, estudando-se também mecanismos de resistência ativados no tecido vegetal em resposta ao tratamento de melhor eficiência. Para tanto, foram utilizadas as concentrações de 0; 0,5; 1,0; 1,5; 2,0 e 3,0% de quitosana e as doses de 0,52; 1,04; 3,13; 10,44 e 15,66 kJ.m-2 da radiação UV-C. A quitosana inibiu o crescimento micelial do fungo e estimulou a germinação e formação de apressórios, os quais se mostraram morfologicamente alterados. A UV-C não inibiu o crescimento micelial, porém a maior dose ocasionou o menor crescimento. Para os experimentos in vivo, laranjas foram coletadas, lavadas, sanitizadas com hipoclorito e posteriormente tratadas. As concentrações de 0,5, 1,0 e 2,0% de quitosana e a dose de 7 kJ m-2 da UV-C apresentaram melhor resultado em laranjas ?Valência? na redução dos sintomas. Análise da cor da casca dos frutos irradiados revelou que houve leve escurecimento. Os fungicidas tiabendazol e imazalil não controlaram a doença em laranjas ?Pêra Rio?, porém, obteve-se menos lesões nos frutos tratados com os fungicidas em combinação com quitosana, tanto em temperatura ambiente quanto em refrigeração. Análises da cor da casca indicaram amarelecimento e não houve alterações significativas nos teores de sólidos solúveis, acidez titulável, pH, vitamina C e ratio. Nos ensaios com quitosana, tiabendazol e UV-C, a quitosana apresentou melhor controle da doença, aplicada isoladamente ou em conjunto com o fungicida e UV-C, em temperatura ambiente ou refrigeração. A quitosana e a proteína harpina apresentaram controle semelhante e, em comparação com o ácido cítrico, a quitosana ocasionou melhor controle em laranjas ?Valência?. Para análises bioquímicas, amostras de flavedo foram homogeneizadas em de tampão acetato, com posterior centrifugação, coletando-se o sobrenadante. Para as reações enzimáticas, foram utilizados os reagentes CM-chitin-RBV, CMCurdlan- RBB, guaiacol, catecol e L-fenilalanina para quitinase, glucanase, peroxidase, polifenoloxidase e fenilalanina amônia-liase, respectivamente. Para a determinação de fenóis, amostras do flavedo foram homogeneizadas em metanol acidificado e a dosagem feita com o reagente Folin-Ciocalteau. A quitosana induziu o aumento da atividade das enzimas nas primeiras 24 h após o tratamento, sendo neste tempo detectada a maior atividade. Não houve atividade de fenilalanina amônia-liase, bem como acúmulo de fenóis. Finalmente, fica evidenciado que quitosana e a UV-C apresentaram efeito in vitro sobre G. citricarpa, porém somente a quitosana exibiu potencial no controle da mancha preta em laranja pós colheita. / Brazil is the biggest producer and exporter of orange juice, and this is one of the most important economical activities for the country. The fruits can be affected by the citrus black spot, disease caused by the fungus Guignardia citricarpa, which depreciates then commercially, causes premature fall and increases the production cost. Alternative measures to the chemical control are being studied and, in this context, resistance induction can be considered. The present work had as objective evaluate the in vitro effects of chitosan and UV-C radiation on mycelial growth, germination and apressorium formation by G. citricarpa and the action of the abiotic agents on controlling the disease on postharvest oranges, under room temperature and refrigeration storage, also studying the mechanisms of resistance in the plant tissue in response to the better treatment. The chitosan concentrations were 0, 0.5, 1.0, 1.5; 2.0 and 3.0% and the UVC doses were 0.52, 1.04, 3.13, 10.44 and 15.66 kJ.m-2. Chitosan inhibited mycelial growth and stimulated the germination and the apressorium formation that were morphologically abnormal. UV-C did not inhibited mycelial growth, but reduced it at the highest dose used. For the in vivo experiments, oranges were collected, sanitized with hypochlorite and treated. Chitosan concentrations of 0.5, 1.0 and 2.0% and the UV-C dose of 7 kJ m-2 exhibited better results in ?Valência ? oranges. Analyses of peel color of irradiated fruits revealed a light browning. The fungicides thiabendazole and imazalil did not control the disease in ?Pêra Rio ? oranges, but fewer lesions appeared on fruits treated with the fungicides in association with chitosan, under room temperature and refrigeration. Color analysis of peel indicated yellowing and no significant differences among soluble solids, titratable acidity, pH vitamin C and ratio. In the chitosan, thiabendazole and UV-C assays, there was a better control of lesion appearing by treatment with chitosan, applied alone or in association with fungicide and UV-C, at room temperature or refrigeration. Chitosan and the harpin protein were similar on the controlling of the disease and, in comparison to the citric acid, chitosan presented better control on ?Valência? oranges. For biochemical analysis, flavedo samples were homogenized in acetate buffer, centrifuged, and the supernatant collected. The reagents used were CM-chitin-RBV, CM-Curdlan-RBB, guaiacol, cathecol and L-phenylalanine for chitinase, glucanase, peroxidase, polyphenoloxidase and phenylalanine ammonia-lyase, respectively. For phenol determination, flavedo was homogenized in acidified methanol and the evaluation was made with Folin-Ciocalteau. Chitosan increased enzyme activities in the first 24 h after treatment, with the highest activity in that time. Activity of phenylalanine ammonia-lyase was not detected, well as absent of phenolic compounds accumulation. Chitosan and UV-C exhibited in vitro effect on G. citricarpa, however, only chitosan showed potential on the control of black spot in postharvest oranges.

Citrus black spot (CBS), caused by Guignardia citricarpa Kiely, occurs in various citrus producing regions of the world. Due to the potential phytosanitary risk associated with the export of fruit from CBS positive production areas to CBS-free countries, restrictive trade barriers have been introduced. This study aimed to further elucidate some epidemiological aspects of CBS that can be used to address critical questions identified in the pest risk assessment submitted by South Africa to the World Trade Organisation to address phytosanitary trade restrictions. Results indicated that Eureka lemon leaf litter exposed to viable pycnidiospores under controlled conditions or in the field in different production regions of South Africa, were not infected and colonised by G. citricarpa. Symptomatic CBS fruit or peel lying on the ground underneath citrus trees therefore can not lead to infection and colonisation of freshly detached leaves or leaf litter, or represent a source of inoculum in citrus orchards. Symptomatic fruit therefore pose no danger for the establishment of the pathogen in CBS-free orchards and are not considered to be a pathway for the pathogen. The period of leaf susceptibility to G. citricarpa was indicated to be maximum eight and ten months from development, for Valencia orange and Eureka lemon, respectively, in a greenhouse study. The susceptibility period of citrus leaves to infection by the black spot pathogen could be longer than previously perceived. Ascospores were captured, using the newly developed Kotzé Inoculum Monitor (KIM), from natural Valencia orange and Eureka lemon leaf litter during October to March with peak ascospore availability between December to February. The KIM is the first sampler designed to capture fungal spores directly from plant material in the laboratory without environmental influences and was effectively used to confirm that ascospores production is seasonal. The KIM in combination with environmental data can be used to improve control through more targeted fungicide applications. Techniques such as isolations and DNA amplification with species-specific primers to detect the pathogen directly from symptomless green leaves have a low success rate due to the restricted growth of the pathogen in latently infected tissue. Artificial leaf wilting enhanced the detection of G. citricarpa from symptomless leaves. Leaf wilting is a reliable, fast and effective method to detect the CBS pathogen and can be applied to monitor citrus nurseries and orchards throughout the year. It can also be applied to monitor pest-free orchards to maintain its CBS pest-free status. This study confirmed that sanitation practices, such as leaf litter removal and mulching of leaf litter with wheat straw can decrease the primary inoculum, ascospores, of CBS and contribute to better management of the disease in a commercial orchard. Regardless of the prevailing climatic conditions each year, control achieved through leaf litter management resulted in >95% clean fruit and are equal to the control achieved with industry standard fungicides. This approach provided improved integrated disease control and an alternative to chemical control. / Thesis (PhD)--University of Pretoria, 2010. / Microbiology and Plant Pathology / unrestricted

Please read the abstract in the dissertation. Copyright / Dissertation (MSc (Plant Pathology))--University of Pretoria, 2007. / Microbiology and Plant Pathology / unrestricted

Citrus black spot (CBS) caused by Guignardia citricarpa is responsible for economic losses in Southern African countries such as South Africa, Mozambique, Swaziland, Zimbabwe and Namibia. Black spot is considered to be a phytosanitary disease for the European Union and the United States of America markets. Exporters to these countries incur losses throughout the supply chain due to phytosanitary restrictions. For these reasons, the occurrence and management practices of CBS and its impact on growers in Southern Africa were investigated through a survey using a questionnaire. In the study, it was found that when CBS was present it was primarily managed by using chemicals and general orchard sanitation. In addition, growers in some of the surveyed countries or production regions follow spraying programs that are based on disease forecasting models and this practice has proven very effective in managing the disease. Furthermore, furfural, a sugarcane waste product was assessed for its efficacy in controlling G. citricarpa. The efficacy of the product as a contact or a fumigant was demonstrated in vitro and in vivo on fresh leaves, leaf litter and fruit lesions as well as in soil. A molecular study, using a Polymerase Chain Reaction protocol was conducted to assess the survival of the pathogen in the soil after exposure to furfural. The product however only proved efficient under natural conditions. The non-target effect of furfural on the soil micro-flora was also assessed. The product proved suitable for soil applications as it is not phytotoxic and has minimal non-target effects on bacterial populations. Furfural proved to control G. citricarpa, by breaking the life cycle, thus reducing the disease incidence. The application of furfural on a larger scale (irrigation or spraying) will therefore improve the control of CBS in developing countries. / Dissertation (MInstAgrar)--University of Pretoria, 2008. / Microbiology and Plant Pathology / unrestricted

A mancha preta dos citros é uma doença que limita a exportação de laranja brasileira para os países da Europa. Exceto para Citrus aurantium e seus híbridos, todas as outras variedades são susceptíveis ao patógeno. Com isso existe um grande interesse para que esta doença não ocorra, uma vez que é considerada uma doença quarentenária A1. Problemas associados à aquisição de resistência e a percepção do público em geral sobre o impacto potencial das práticas tradicionais de controle sobre a saúde e meio ambiente levaram a uma crescente demanda por produtos livres de resíduos químicos. Em vista disso, este trabalho verificou o efeito dos extratos aquosos do albedo de C. sinensis, L. edodes, A. blazei e da suspensão de S. cerevisiae no controle da mancha preta dos citros quando associados a refrigeração. Os frutos de C. sinensis var. Valência, após serem tratados pelos extratos, permaneceram durante 21 dias a 3 ºC e posteriormente 4 dias a 25 ºC, foram realizadas cinco avaliações ao longo do experimento. Neste trabalho, também verificou-se a eficiência dos compostos orgânicos voláteis produzidos por S. cerevisiae no controle da mancha preta dos citros quando aplicados em pós-colheita. A linhagem CR-1 da levedura S. cerevisiae foi colocada para crescer em placas de poliestireno contendo meio de batata-dextroseágar e colocada em recipientes de vidro de 3 L fechados, junto com frutos de C. sinensis var. Valência apresentando sintomas de mancha preta dos citros. E por fim, verificou-se a eficiência de diferentes compostos orgânicos identificados a partir da S. cerevisiae, obtidos a partir de produtos disponíveis comercialmente, que foram utilizados para verificar o crescimento micelial a germinação e a formação de apressório por G. citricarpa, e o controle da mancha preta dos citros em pós-colheita. Como resultado, os extratos aquosos do albedo de C. sinensis, L. edodes e A. blazei apresentaram potencial como agentes de controle sobre a mancha preta dos citros em frutos de laranja (C. sinensis var. Valência) associados a refrigeração, pois apresentaram inibição no aparecimento de novas lesões. Os compostos voláteis produzidos por S. cerevisiae inibiram a expressão de sintomas em frutos de C. sinensis var. Valência, quando tratados em pós-colheita, sendo que os compostos orgânicos voláteis, 2-metil-1-butanol e 3-metil-1-butanol apresentaram inibição sobre Guignardia citricarpa in vitro e atuaram como agentes de controle, inibindo o aparecimento de novas lesões em frutos de laranja Valência, apresentando sintomas de mancha preta, quando aplicados em pós-colheita. / The citrus black spot is a disease that restricts the export of Brazilian oranges to the countries in Europe. Except for Citrus aurantium and its hybrids, all other varieties are susceptible to the pathogen. Thus, there is great interest that this disease does not occur, since it is considered a quarantine A1 disease. Problems associated with the acquisition of fungal resistance and the perception of the general public about the potential impact of traditional control measures over the health and the environment led to a growing demand for products free of chemical residues. Thus, this study was carried out to investigate the effect of aqueous extracts of the albedo of C. sinensis, L. edodes, A. blazei and the suspension of S. cerevisiae cells in the control of citrus black spot when associated with cooling. The fruits of C. sinensis var. Valencia, after being treated with the extracts, were stored for 21 days at 3 º C and then 4 days at 25 ° C (there were five evaluations during the experiment). This work also verified the efficiency of volatile organic compounds produced by S. cerevisiae in the control of citrus black spot when applied in post-harvest. The CR-1 strain of yeast S. cerevisiae was put to grow inside polystyrene plates containing potato-dextrose-agar medium. The plates were placed in closed glass containers of 3 L, along with fruits of C. sinensis var. Valencia showing symptoms of citrus black spot. Finally, it was verified the effect of different organic compounds, identified from the S. cerevisiae and obtained from commercially available products, on in vitro mycelial growth, germination and appressorium formation by G. citricarpa and on the in vivo control of citrus black spot under post-harvest conditions. The results showed that the aqueous extracts of the albedo of C. sinensis, L. edodes and A. blazei exhibit potential to control the black spot in orange (C. sinensis var. Valencia) associated with cooling, since they inhibited the appearance of new lesions. The volatile compounds produced by S. cerevisiae inhibited the expression of symptoms in fruits of C. sinensis var. Valencia, when treated in postharvest. On the other hand, the microbial volatile organic compounds, 2-methyl-1- butanol and 3-methyl-1-butanol inhibited the growth of Guignardia citricarpa in vitro and acted as control agents by inhibiting the appearance of new lesions of black spot in fruits of Valencia orange when applied in post-harvest.

A citricultura brasileira concentra-se principalmente no Estado de São Paulo que contribui com 80,4 % da produção nacional, sendo o Brasil um dos maiores produtores mundiais de citros. Um dos problemas enfrentados pela citricultura é a sua vulnerabilidade a pragas e doenças, devido principalmente a baixa diversidade genética nas variedades comerciais utilizadas, associada ao sistema de plantio em áreas extensas. Uma das doenças que vem causando crescentes prejuízos para a citricultura brasileira é a pinta preta ou mancha preta dos citros causada pelo fungo Guignardia citricarpa Kiely. O uso de conhecimentos de biologia molecular e métodos biotecnológicos devem ser considerados como importante alternativa para a produção de plantas geneticamente modificadas expressando genes de resistência. Para se obter plantas de citros resistentes a doenças, se faz necessário identificar genes que estejam relacionados com os mecanismos de defesa da planta. Na tentativa de identificar estes genes, o objetivo geral deste trabalho foi a identificação de genes in silico no banco de dados do Projeto Millenium CitEST e a análise de expressão diferencial de genes envolvidos na defesa. Mais de 7600 sequencias foram identificadas nas buscas no CitEST com similaridade aos genes R e genes envolvidos na HR e defesa, MAPKs e SNF1. Destes, foram selecionados 273 sequencias para experimentos de macroarranjo para análise da interação Citrus sinensis-Guignardia citricarpa. A análise estatística revelou que 171 genes (62,63%) apresentaram expressão diferencial significativa ao nível de 5% de probabilidade. Destes, 80 apresentaram expressão diferencial significativa maior do que duas vezes, dos quais 38 genes foram induzidos e 42 foram reprimidos no tecido infectado. Entre os genes induzidos estão MAPKs, genes de resistência (R), genes envolvidos na resposta de hipersensibilidade (HR) e na defesa da planta. Entre os transcritos reprimidos, há quatro similares a peroxidases e cinco similares a catalases, o que era esperado já que catalases e algumas peroxidases são capazes de remover H2O2, e assim a planta produz espécies reativa de oxigênio capaz de desencadear a ativação de genes de defesa. Os dados do macroarranjo foram validados via transcrição reversa seguida de PCR quantitativo em tempo real (RT-PCRq) de 9 genes. As análises confirmaram a expressão diferencial de 8 deles sendo que somente um apresentou resultado contrastante ao macroarranjo, o que demonstra a eficiência da metodologia de macroarranjos para estudo de muitos genes simultaneamente. Os genes diferencialmente expressos identificados na interação C. sinensis-G. citricarpa são de grande importância, pois são fortes candidatos para serem utilizados na transformação genética de plantas com o objetivo de obter novas variedades de plantas com resistência a patógenos. / The Brazilian citrus industry is concentrated mainly in the State of Sao Paulo which contributes with 80.4% of national production, with Brazil being a leading world producer of citrus. One of the problems facing the citrus industry is its vulnerability to pests and diseases, mainly due to low genetic diversity of the commercial varieties used, linked to the system of planting in extensive areas. A disease that is causing increasing damage to the brazilian citrus industry is the black spot of citrus caused by the fungus Guignardia citricarpa Kiely. The use of knowledge of molecular biology and biotechnological methods should be considered as an important alternative for the production of genetically modified plants expressing genes for resistance. In order to obtain citrus plants resistant to diseases it is necessary to identify genes that are related to the defense mechanisms of the plant. In an attempt to identify these genes, the general aim of this study was to identify genes in silico in the database of the Millennium CitEST Project and to perform differential expression analysis of genes involved in the defense mechanisms. More than 7600 reads were identified in the CitEST search with similarity to R genes, genes involved in HR and defense, MAPKs and SNF1. It was selected 273 reads for macroarray experiments to analysis of Citrus sinensis-Guignardia citricarpa interaction. Statistical analysis revealed that 171 genes (62.63%) showed significant differential expression at the level of 5% probability. From these, 80 showed significant differential expression higher than two fold, in which 38 genes were induced and 42 were repressed in infected tissue. Among the induced genes are MAPKs, resistance (R) genes, genes involved in hypersensitivity response (HR) and plant defense. Among the suppressed transcripts, there are four similar to peroxidases and five similar to catalases, which is expected because catalases and some peroxidases are able to remove H2O2, and so the plant produces reactive oxygen species capable of triggering the activation of defense genes. The macroarray data were validated by reverse transcription followed by quantitative real-time PCR (RT-PCRq) of 9 genes. The analysis confirmed the differential expression of 8 of them, and only one presented different result of macroarray which demonstrate the efficiency of the macroarray methodology to analyze several genes simultaneously. The genes differentially expressed in the interaction of C. sinensis x Guignardia citricarpa identified are of great importance because they are strong candidates for use in genetic transformation of plants with the objective of obtaining new varieties of plants resistant to pathogens.

A mancha preta dos citros (MPC), causada por Phyllosticta citricarpa, é uma doença de importância econômica devido à redução na produtividade ocasionada pela queda prematura dos frutos e ao aumento dos custos da produção devido ao uso intensivo de fungicidas. As lesões restringem-se praticamente ao flavedo dos frutos, depreciando-os para a comercialização e restringindo a exportação de frutas in natura. A MPC causa danos em todas as espécies cítricas de valor comercial, com exceção da Citrus aurantium (laranja azeda) e do Citrus latifólia (lima ácida Tahiti). Phyllosticta citricarpa causa infecções latentes e diferentes tipos de sintomas nos frutos. Essas características podem estar relacionadas com o estádio fenológico do fruto no momento da infecção. Os objetivos desse trabalho foram avaliar a influência da idade dos frutos de laranja doce na germinação dos conídios e no período de incubação de P. citricarpa e identificar compostos fenólicos pré ou pós-formados no flavedo de frutos de laranja doce inoculados com P. citricarpa. Frutos de laranjeira das variedades Hamlin, Valência e Pêra com 1,5, 3,0, 5,0 e 7,0 cm de diâmetros foram inoculados com suspensão de conídios de P. citricarpa na concentração de 103 e 105 conídios.mL-1 e avaliados mensalmente. O primeiro sintoma observado foi o da falsa melanose e não foram observadas diferenças no período de incubação entre as variedades. O período de incubação da falsa melanose foi afetado pela concentração de inóculo e pelo diâmetro dos frutos. Frutos de 1,5 e 3,0 cm de diâmetro inoculados com suspensão de conídios de P. citricarpa, na concentração de 103 conídios.mL-1, apresentaram sintomas entre 70 e 116 dias respectivamente, enquanto que os frutos de 1,5, 3,0 e 5,0 cm de diâmetro, inoculados com suspensão de 105 conídios.mL-1, expressaram sintomas entre 40, 65 e 156 dias respectivamente. A expressão dos sintomas de mancha dura não diferiu entre as concentrações de inóculo, mas diferiu entre os diâmetros e entre as variedades avaliadas. A variedade Valência apresentou os menores tempos para o aparecimento dos sintomas quando comparado com as variedades Hamlin e Pêra. Os tempos médios para a expressão da mancha dura nos frutos (todas as variedades) inoculados com 1,5, 3,0, 5,0 e 7,0 cm de diâmetro foram 240, 217, 176 e 197 dias respectivamente. Sintomas de falsa melanose e mancha dura se expressaram independente um do outro. Não foi observado diferenças nas quantidades dos compostos fenólicos entre os frutos inoculados e não inoculados após 48 h de câmara úmida. As maiores quantidades de compostos fenólicos foram encontradas nos frutos menores e à medida que estes aumentaram de tamanho, observou-se a diminuição nas quantidades destes compostos. Não foram observadas diferenças no padrão de germinação do fungo em relação aos diferentes diâmetros inoculados, porém foram observadas placas de cera na superfície dos frutos de 7,0 cm de diâmetro. Os sintomas de falsa melanose parecem estar relacionados com a defesa da planta, e os sintomas de mancha dura estão relacionados com o estádio fenológico dos frutos. / Citrus black spot (CBS), caused by Phyllosticta citricarpa, is a disease of economic importance due to the reduction in yield, caused by premature fruit drop, and high production costs, due to the intensive fungicide spraying. The lesions are restricted to the fruit flavedo, decreasing market prices and restricting exports of fresh fruits. CBS causes damage in all commercial citrus species with exception of Citrus aurantium (sour orange) and Citrus latifolia (Tahiti acid lime). Phyllosticta citricarpa causes latent infections and different types of symptoms on fruit. These characteristics may be related to the phenological stage of the fruit at the time of infection. The objectives of this study were to evaluate the influence of fruit age of sweet orange on conidia germination and on the incubation period of P. citricarpa and identify phenolics pre or post-formed in the flavedo of sweet orange inoculated with P. citricarpa. Orange fruits of varieties Hamlin, Valencia and Pera with 1.5, 3.0, 5.0 and 7.0 cm of diameters were inoculated with a conidia suspension of P. citricarpa at the concentration of 103 and 105 conidia.mL-1 and were evaluated monthly. The first symptom observed was false melanose and no differences were found in the incubation period among the varieties. The incubation period of false melanose was affected by the inoculum concentration and fruit diameters. Fruits with 1.5 and 3.0 cm of diameter inoculated with a conidia suspension of P. citricarpa, at a concentration of 103 conidia.mL-1, showed symptoms between 70 and 116 days, respectively. On the other hand, fruits with 1.5, 3.0 and 5.0 cm in diameter, inoculated with suspension of 105 conidia.mL-1, expressed symptoms between 40, 65 and 156 days, respectively. The period for symptom expression of hard spot did not differ between inoculum concentrations. The incubation period differed between the diameters and varieties evaluated. The Valencia variety presented symptoms in a shorter time than Hamlin and Pera. The average times for hard spot expression in fruits (all varieties together) inoculated with 1.5, 3.0, 5.0 and 7.0 cm of diameter were 240, 217, 176 and 197 days, respectively. Symptoms of false melanose and hard spot were expressed independently from each other. No differences were observed in the amounts of phenolic compounds between inoculated and non-inoculated fruits after 48 h of incubation in a humid chamber. The highest amounts of phenolic compounds were found in smaller fruits and, as fruits increased size, there was a decrease in the amounts of these compounds. No differences were found in the germination pattern of fungus on the inoculated fruits, but wax plates were observed on the surface of fruits with 7.0 cm in diameter. Symptoms of false melanose seem to be related to the plant defense mechanism, and symptoms of hard spot appeared to be related with phenological stages of the fruits.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-17T14:46:49Z No. of bitstreams: 1 Cicero Nicolini.pdf: 204101 bytes, checksum: 7157eb0dfbcf608b64b0ae9bbbaf5c05 (MD5) / Made available in DSpace on 2017-02-17T14:46:49Z (GMT). No. of bitstreams: 1 Cicero Nicolini.pdf: 204101 bytes, checksum: 7157eb0dfbcf608b64b0ae9bbbaf5c05 (MD5) Previous issue date: 2008-03-03 / The Alternaria black spot is one of the most common and destructive diseases of brassica species. This disease can be caused by several species of Alternaria, although A. brassicicola is predominant species in both conventional and organic crops in Brazil. Since commercial cultivars of brassica with acceptable levels of disease resistance are not available, the disease control in conventional production system is based on the fungicide applications, while in the organic production system the disease control on relays on cultural methods. The objective of this study is to assess the sensitivity of 112 isolates of A. brassicicola to fungicide groups: benzimidazoles (carbendazim), dicarboximides (iprodione), triazoles (tebuconazole) and strobilurines (azoxystrobin). The isolates were evaluated in vitro to obtain the concentration capable of inhibiting 50% of the mycelial growth (CL50) and separated in four classes depending on the sensibility to the tested fungicides. All the isolated of A. brassicicola were sensitive the iprodione, with CL50 values below to 0.1 mg i.a./L. Most of the isolates originating from conventional (92.9%) and organic (96.4%) were middling resistant the azoxystrobin, while an isolated (CFM-576) was highly resistant. In relation to tebuconazole, only isolated sensitive (42.9%) and lightly resistant (57.1%) were observed. There was nosignificant difference between the isolates of A. brassicicola originated either from conventional or organic systems and brassica types regarding the levels of sensitivity to the fungicides. / A alternariose é uma das doenças foliares mais comuns e destrutivas das brássicas, podendo ser causada por várias espécies de Alternaria, embora A. brassicicola seja a espécie predominante em plantios convencionais e orgânicos no Brasil. Como inexistem cultivares comerciais de brássicas com níveis aceitáveis de resistência à doença, no sistema de produção convencional o controle da doença se baseia na aplicação de fungicidas, enquanto no sistema orgânico em métodos culturais. O presente trabalho teve como objetivo avaliar a sensibilidade de 112 isolados de A. brassicicola oriundos de cultivos convencionais e orgânicos de brássicas a fungicidas dos grupos dicarboximidas (iprodione), triazóis (tebuconazole) e estrobilurinas (azoxystrobin). Os isolados foram avaliados in vitro visando obter a concentração capaz de inibir 50% do crescimento micelial (CL50) e separados em quatro classes dependendo da sua sensibilidade aos fungicidas testados. Todos os isolados de A. brassicicola foram sensíveis a iprodione, com valores de CL50 inferiores a 0,1 mg i.a./L. A maioria dos isolados oriundos de cultivos convencionais (92,9%) e orgânicos (96,4%) se comportou como medianamente resistente a azoxystrobin, enquanto um isolado (CFM-576) foi altamente resistente. Em relação a tebuconazole, foram constatados somente isolados sensíveis (42,9%) e ligeiramente resistentes (57,1%). Não foi encontrada diferença significativa quanto à sensibilidade aos fungicidas testados entre os isolados de A. brassicicola oriundos de cultivos convencionais e orgânicos, bem como, coletados de diferentes tipos de brássicas.

Orientador: Wagner Bettiol / Banca: Antonio Carlos Maringoni / Banca: Lilia Aparecida Salgado de Morais / Banca: Eliane Aparecida Benato R. da Silva / Banca: Edson Luiz Furtado / Resumo: Penicillium digitatum, agente causador do bolor verde, e Guignardia citricarpa, agente causador da mancha preta, depreciam os frutos citricos. O controle desses patógenos em frutos é realizado com fungicidas sintéticos. Devido a preocupação da sociedade com os riscos de contaminação ambiental, intoxicação humana principalmente infantil e animal e ao surgimento de isolados fúngicos resistentes aos fungicidas sintéticos, estão em desenvolvimento técnicas alternativas aos fungicidas para uma agricultura mais sustentável. O objetivo do trabalho foi avaliar os efeitos de óleos essenciais e fixos e dos agentes de biocontrole no controle de P. digitatum e G. citricarpa em frutos laranja Pêra em pós- colheita. Assim, foram testados os óleos fixos de Allium sativum, Copaifera langsdorffii, Azadirachta indica; e os óleos essenciais de Pogostemon cablin, Mentha arvensis, Eucalyptus spp., Cymbopogon citratus, Ocimum basilicum var. Maria bonita, Romarinus officinalis, Lippia sidoides, Zingiber officinale, Citrus aurantifolia, Piper aduncum e Ocimum basilicum. Além dos óleos, também foram estudados os seguintes agentes de biocontrole: Bacillus subtilis (Serenade®), Bacillus subtilis e Bacillus lichiniformes (Nemix®), Pichia guilliermondii (L29), Sporobolomyces roseus (L41), Rhodotorula mucilagenosa (L17), Sporodiobolus pararoseus, Pichia sp. (L4-1), Debaryomyces hansenii (L62), Pichia membranifaciens (L21) e uma bactéria isolada da laranja. Tanto os agentes de biocontrole, quanto os óleos foram testados in vivo e in vitro contra os dois patógenos. Para a avaliação da atividade dos óleos essenciais e dos antagonistas in vivo, no controle de P. digitatum, foram utilizadas laranjas Pêra. Cada fruto foi ferido em dois pontos opostos, na região equatorial, atingindo a região do albedo. Após o ferimento, os frutos foram inoculados com 20 μL da suspensão de conídios... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Penicillium digitatum, causal agent of green mold, and Guignardia citricarpa causal agent of black spot. Detracts the citrus fruit, the control of these pathogens is made with synthetic fungicides. Due to concern about the risks of environmental contamination, human, mainly children and animal toxicity and the emergence of fungal isolates resistant to fungicides, various researches has been development to obtain alternative techniques for a fungicides. The objectives of this work was to evaluate the effetives fix and essencial oils and biocontrol agents for the control of P. digitatum and G. citricarpa on Pera orange fruits in postharvest. Thus, were tested the fixed oils from Allium sativum, Copaifera langsdorffii, Eucalyptus spp. Azadirachta indica,and the essential oils of Pogostemon cablin, Mentha arvensis, Cymbopogon citratus, Ocimum basilicum var. Maria bonita, Romarinus officinalis, Lippia sidoides, Zingiber officinale, Citrus aurantifolia, Piper aduncum and Ocimum basilicum. In addition were also studied the following biocontrol agents: Bacillus subtilis (Serenade ®), Bacillus subtilis and Bacillus lichiniformes (Nemix ®), Pichia guilliermondii (L29), Sporobolomyces roseus (L41), Rhodotorula mucilagenosa (L17), Sporodiobolus pararoseus, Pichia spp. (L4-1), Derbaryomyces hansenii (L62), Pichia membranifaciens (L21) and a bacterium isolate of the orange. Both biocontrol agents as the oils, were tested in vivo and in vitro against both pathogens. For the assessment of activity of essential oils and antagonists in vivo in controlling P. digitatum were used Pera orange. Each fruit was wounded in two opposite points in the equatorial region, reaching the albedo. After the injury, the fruits were inoculated with 20 mL of conidial suspension of P. digitatum (105 conidia / mL), followed by immersion in a suspension of cells of each biocontrol agent in the concentration: ...(Complete abstract click electronic access below) / Doutor