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Made available in DSpace on 2014-06-11T19:32:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-07Bitstream added on 2014-06-13T18:43:53Z : No. of bitstreams: 1 peres_nar_dr_botfca.pdf: 1562293 bytes, checksum: 80875212025872cc8702cb8d95533821 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A podridão floral, causada por Colletotrichum acutatum, afeta flores de citros e induz à abscisão de frutos jovens, sendo considerada um sério problema na maioria das áreas úmidas onde se produz citros nas Américas. O controle da doença é feito pela pulverização de fungicidas durante a florada porém, uma das dificuldades é determinar o momento ideal para o controle. Um modelo de previsão foi desenvolvido na Flórida para indicar a necessidade de pulverização, considerando a quantidade de inóculo, chuvas e molhamento foliar. Este modelo foi avaliado durante três anos consecutivos na região de Itapetininga-SP. Verificou-se que mediante a aplicação do modelo obteve-se um bom controle da doença, tendo-se evitado duas pulverizações desnecessárias em comparação com o calendário, em 1999, e uma pulverização, comparado ao esquema do produtor, em 2000 e 2001. Um novo sistema de previsão para controle da podridão floral (PFD-FAD) foi desenvolvido incorporando outros fatores que também influenciam a ocorrência da doença, como o histórico do pomar, a suscetibilidade da variedade, o estágio de desenvolvimento da florada, assim como chuva, molhamento foliar e nível de inóculo, além da data da última... . / Postbloom fruit drop (PFD), caused by Colletotrichum acutatum Simmonds, infects petals of citrus flowers and induces the abscission of fruitlets. The disease can cause serious losses in most humid areas where citrus is produced in the Americas. The disease is controlled by fungicide applications during the bloom but it is difficult to properly time applications. A model was developed in Florida to schedule fungicide applications based on the amount of inoculum and the amount of rainfall and leaf wetness for the last 5 days. This model was evaluated during three consecutive years in Itapetininga-SP, Brazil. Results showed that applications following the model provided good control of the disease and saved two sprays compared to the calendar program in 1999, and one spray compared to the grower’s choice in 2000 and 2001. A new advisory system (PFD-FAD) was developed to be more widely applicable by incorporating risk factors that are inherent in any planting which affected by PFD incidence. The history of the disease in the grove, the varietal susceptibility, the stage of the bloom, as well as the rain, leaf wetness, the amount of inoculum and the last spray date were considered. Field tests in 2001 showed that the system provided good control of the disease with only one fungicide application. Benomyl is considered one of the most effective products for PFD control but despite that C. acutatum is not highly sensitive to benomyl in culture. The mycelial growth and conidial germination is inhibited by 80% at concentration of 1.0 μg/mL, but higher concentrations do not completely inhibit the growth of the fungus. Colletotrichum gloeosporioides, a common saprophyte and causal agent of anthracnose of fruits postharvest, is completely inhibit by 1.0 μg/mL... (Complete abstract, click electronic address below).

Orientador: Nilton Luiz de Souza / Resumo: A podridão floral, causada por Colletotrichum acutatum, afeta flores de citros e induz à abscisão de frutos jovens, sendo considerada um sério problema na maioria das áreas úmidas onde se produz citros nas Américas. O controle da doença é feito pela pulverização de fungicidas durante a florada porém, uma das dificuldades é determinar o momento ideal para o controle. Um modelo de previsão foi desenvolvido na Flórida para indicar a necessidade de pulverização, considerando a quantidade de inóculo, chuvas e molhamento foliar. Este modelo foi avaliado durante três anos consecutivos na região de Itapetininga-SP. Verificou-se que mediante a aplicação do modelo obteve-se um bom controle da doença, tendo-se evitado duas pulverizações desnecessárias em comparação com o calendário, em 1999, e uma pulverização, comparado ao esquema do produtor, em 2000 e 2001. Um novo sistema de previsão para controle da podridão floral (PFD-FAD) foi desenvolvido incorporando outros fatores que também influenciam a ocorrência da doença, como o histórico do pomar, a suscetibilidade da variedade, o estágio de desenvolvimento da florada, assim como chuva, molhamento foliar e nível de inóculo, além da data da última... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: Postbloom fruit drop (PFD), caused by Colletotrichum acutatum Simmonds, infects petals of citrus flowers and induces the abscission of fruitlets. The disease can cause serious losses in most humid areas where citrus is produced in the Americas. The disease is controlled by fungicide applications during the bloom but it is difficult to properly time applications. A model was developed in Florida to schedule fungicide applications based on the amount of inoculum and the amount of rainfall and leaf wetness for the last 5 days. This model was evaluated during three consecutive years in Itapetininga-SP, Brazil. Results showed that applications following the model provided good control of the disease and saved two sprays compared to the calendar program in 1999, and one spray compared to the grower's choice in 2000 and 2001. A new advisory system (PFD-FAD) was developed to be more widely applicable by incorporating risk factors that are inherent in any planting which affected by PFD incidence. The history of the disease in the grove, the varietal susceptibility, the stage of the bloom, as well as the rain, leaf wetness, the amount of inoculum and the last spray date were considered. Field tests in 2001 showed that the system provided good control of the disease with only one fungicide application. Benomyl is considered one of the most effective products for PFD control but despite that C. acutatum is not highly sensitive to benomyl in culture. The mycelial growth and conidial germination is inhibited by 80% at concentration of 1.0 μg/mL, but higher concentrations do not completely inhibit the growth of the fungus. Colletotrichum gloeosporioides, a common saprophyte and causal agent of anthracnose of fruits postharvest, is completely inhibit by 1.0 μg/mL... (Complete abstract, click electronic address below). / Doutor

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Made available in DSpace on 2016-06-02T18:57:41Z (GMT). No. of bitstreams: 1 4635.pdf: 1080000 bytes, checksum: 7f72c6154417cfa404d1b1fbb1d30af2 (MD5) Previous issue date: 2012-07-31 / Universidade Federal de Minas Gerais / Brazil is the world's largest producer of orange, seated in an area of 839.000 hectares, of which 77% are located in the southeast. Despite the importance of this crop, the citrus industry faces serious problems represented by fungal diseases that reduce productivity such as citrus post-bloom fruit drop (PDF), caused by Colletotrichum acutatum. As control is predominant spraying chemicals. Considering the financial costs, environmental damage and public health of these applications, it is necessary to study new control alternatives, and among these, the biological control. Therefore this study aimed to develop a formulation of Bacillus subtilis, based different transport vehicles, with or without additives, aiming to control the PDF. The results showed that the powder as a vehicle for transport, provided a greater viability of bacterial cells stored in the two temperatures tested (1 and 22 ° C) for a period of 12 months. In vitro tests showed that the powder plus urea (0.02%) inhibited both the mycelial growth, as the germination of C. acutatum. The additives urea (0.02%) and ammonium molybdate (1mM) optimized the formulation, when tested in the same flower deployed. Control data under field conditions, showed that B. subtilis in powder plus urea (0.02%) yielded 72.7% of flowers without infection by the pathogen and 56.4% of the average number of effective fruits (ANEF) and on the other hand, the control treatment was obtained 8.8% flowers and 0.83% of healthy ANEF, chemical treatment (thiophanate-methyl) showed 69.6% of healthy flowers and 46.7% ANEF. It is concluded that, based formulation B. subtilis, with talc as a transport vehicle, plus an additive (urea 0.02%) kept the viability of bacteria cells and was effective in the controlling of disease. / O Brasil é o maior produtor mundial de laranja, assentado em uma área de 839 mil hectares, dos quais 77% encontram-se localizados na região sudeste do país. Não obstante a importância dessa cultura, o setor citrícola enfrenta sérios problemas representados por doenças fúngicas que diminuem a produtividade, como a podridão floral dos citros (PFC), causada pelo fungo Colletotrichum acutatum. A medida predominante de controle é a pulverização com defensivos químicos. Considerando os custos financeiros, prejuízos ambientais e de saúde pública envolvidos nestas aplicações, faz-se necessário o estudo de novas alternativas de controle e, dentre estas, o controle biológico. Portanto este trabalho teve por objetivo desenvolver uma formulação de Bacillus subtilis, usando diferentes veículos de transportes, com ou sem aditivos, visando o controle da PFC. Os resultados dos testes in vitro mostraram que o talco + uréia (0,02%) inibiram, tanto o crescimento micelial, quanto a germinação de C. acutatum. Os aditivos uréia (0,02%) e molibdato de amônio (1mM) otimizaram a formulação, quando a mesma foi testada em flores destacadas. Resultados de controle, sob condições de campo, revelaram que B. subtilis formulado em talco + uréia (0,02%) proporcionou 72,7% de flores sem infecção pelo fitopatógeno e 56,4% de número médio de frutos efetivos (NMFE); por outro lado, no tratamento testemunha obteve 8,8% de flores sadias e 0,83% de NMFE, o tratamento químico (tiofanato metílico) apresentou 69,6% de flores sadias e 46,7% de NMFE. Conclui-se que, a formulação à base de B. subtilis, tendo o talco como veículo de transporte, acrescido do aditivo uréia (0,02%) é eficiente na manutenção da viabilidade das células bacterianas para o controle da doença.

Made available in DSpace on 2014-06-11T19:28:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-05Bitstream added on 2014-06-13T20:37:50Z : No. of bitstreams: 1 sierrahayer_jf_me_botfca.pdf: 13042883 bytes, checksum: c8c75feb8bc74ce204bc7a174adc9e95 (MD5) / A cultura da seringueira [Hevea brasiliensis (Willd. ex Adr. Jussieu) Muell. Arg.] vem sendo atacada por várias doenças de importância econômica, dentre as quais está a antracnose, causada pelo fungo Colletotrichum sp. (teleomorfo: Glomerella sp.). Este fungo causa vários danos na planta como lesões nos folíolos, nos ponteiros, nos ramos, nos frutos e cancros no painel de sangria. Somente Colletotrichum gloeosporioides foi relatado como agente causal desta doença no Brasil. O presente trabalho teve como objetivo identificar isolados de Colletotrichum spp. de seringueira de diversas regiões de plantio do Estado de São Paulo. O trabalho foi conduzido em cinco fases: a) caracterização cultural, na qual foram observadas a coloração e o aspecto das culturas in vitro. Produção de conídios e taxa de crescimento em seis temperaturas (10, 15, 20, 25, 30 e 35 °C); b) caracterização morfológica, na qual foi medido comprimento, largura e observado o formato dos conídios; c) teste de patogenicidade em folíolos destacados e em discos de folíolos, com quatro isolados de seringueira e dois de citros; d) crescimento em benomyl em quatro concentrações de princípio ativo; e) Identificação molecular para culturas monospóricas e multispóricas com primers específicos para as espécies de Colletotrichum gloeosporioides e Colletotrichum acutatum e os primers ITS1 e ITS4 os quais amplificaram uma pequena região (18S) e uma grande região (28S), e estes também permitiram a amplificação da região 5.8S do rDNA e os espaçadores internos transcritos (ITS1 e ITS2), e f) testes de crescimento em meio de cultivo acrescido com fungicidas: flutriafol, tebuconazol, epoxiconazol + piradostrobina, clorotalonil + tiofonato-metílico, captana, mancozebe, carbendazim, azoxistrobina + ciproconazol e propiconazol. Neste teste foram utilizados quatro isolados de diferentes órgãos da planta... / The rubber cultivation [Hevea brasiliensis (Willd. ex Adr. Jussieu) Muell. Arg.] is being attacked by several diseases of economic importance, among which is the anthracnose; this is caused by the fungus Colletotrichum spp. (teleomorph: Glomerella spp). This fungus causes several damages in the plant such as injuries in the leaves, branches, fruits and cankers in the taping panel. Only Colletotrichum gloeosporioides was reported as the causal agent of this disease in Brazil. The aim of this study was to identify isolates of the fungus Colletotrichum spp. from rubber trees, localized in different regions of Sao Paulo state. The study was carried out by six phases: a) culture characterization, in which the color and the culture appearance were observed in vitro, conidial production and growth rate at six temperatures (10, 15, 20, 25, 30, 35 °C); b) morphological characterization, which consist of measuring the length and width, and observed the shape of the conidia; c) pathogenicity test on selected leaves and disks of leaves, with four isolates from rubber and two isolates from citrus; d) growth in fungicide benomyl at four concentrations of active ingredient; e) molecular identification for monosporic and multisporic cultures with specific primers to the species of Colletotrichum gloeosporioides and Colletotrichum acutatum and ITS1 and ITS4 primers which amplified a small region (18S) and a large region (28S), and these also allowed the amplification of 5.8S rDNA and internal transcribed spacers (ITS1 and ITS2); f) Growth tests in culture medium supplemented with fungicides: flutriafol, tebuconazole, epoxiconazole + piradostrobina, chlorothalonil + tiofonato-methyl, captan, mancozeb, carbendazim, azoxystrobin + cyproconazole and propiconazole. In this test, four isolates were used from... (Complete abstract click electronic access below)

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-05-03T16:29:44Z No. of bitstreams: 1 texto completo.pdf: 8727950 bytes, checksum: 9b6175ee5adac06db497bf3862a7306a (MD5) / Made available in DSpace on 2016-05-03T16:29:44Z (GMT). No. of bitstreams: 1 texto completo.pdf: 8727950 bytes, checksum: 9b6175ee5adac06db497bf3862a7306a (MD5) Previous issue date: 2015-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho descreve a síntese, caracterização e avaliação da atividade antifúngica de dezoito alilsulfonamidas, seis sulfonamidas primárias e dois intermediários sintéticos. A primeira etapa de síntese ocorreu via reação de Morita-Baylis-Hillman mediante o acoplamento entre benzaldeído e acrilato de metila sob catálise com trimetilamina, utilizando metanol como solvente. O aduto resultante, 2-[hidroxi(fenil)metil]acrilato de metila (2) foi desidratado e convertido no (Z)-2-(bromometil)-3-(fenil)acrilato de metila (3) através de reação com brometo de lítio e ácido sulfúrico em acetonitrila. Nove alilsulfonamidas com dupla ligação C=C interna foram sintetizadas a partir do brometo 3 em reação com nove diferentes sulfonamidas primárias e carbonato de potássio, utilizando acetona como solvente, sob aquecimento. Uma alilsulfonamida com dupla ligação C=C interna (6e) foi sintetizada pela reação entre o aduto 2 e a 4-nitrobenzenossulfonamida em 1,2-dicloroetano, catalisada por ácido sulfúrico, sob aquecimento. Oito alilsulfonamidas com dupla ligação C=C externa à cadeia foram sintetizadas reagindo-se primeiramente o brometo 3 com DABCO em acetonitrila e, em seguida, pela adição de carbonato de potássio e da sulfonamida primária apropriada. As dezoito alilsulfonamidas obtidas são inéditas. Quatro sulfonamidas primárias utilizadas na rota sintética estão disponíveis comercialmente. As demais foram preparadas a partir de seus cloretos de sulfonila, em reação com amônia, sob aquecimento. O aduto 2, o brometo 3, e as sulfonamidas primárias sintetizadas foram caracterizados por temperaturas de fusão e espectroscopia vibracional no infravermelho, em comparação com dados da literatura. As alilsulfonamidas inéditas com fórmulas gerais PhCH=C(COOMe)G (onde G = -NHSO2Me, -NHSO2Et, -NHSO2Bu, - NHSO2Oct, -NHSO2Ph, -NHSO2PhF, -NHSO2PhCl, -NHSO2PhBr, -NHSO2PhI, -NHSO2PhNO2) e PhCH(G)C(COOMe)=CH2 (onde G =-NHSO2Et, -NHSO2Bu,- NHSO2Oct, -NHSO2PhF, -NHSO2PhCl, NHSO2PhBr,-NHSO2PhI,- NHSO2PhNO2) foram caracterizadas pelas técnicas já mencionadas, além de espectrometria de massas de alta resolução (HR-ESI-MS) e ressonância magnética nuclear (RMN) de 1H e 13 C. Os espectros vibracionais permitiram a identificação de algumas ligações químicas e grupos funcionais dos compostos inéditos. Os espectros de RMN de 1H e 13 C apresentaram o número de sinais, multiplicidades e deslocamentos químicos compatíveis com as estruturas propostas. As fórmulas moleculares sugeridas para cada composto foram confirmadas pelos espectros de HR-ESI-MS. Todos os compostos sintetizados tiveram sua atividade antifúngica avaliada frente a Colletotrichum acutatum. As alilsulfonamidas mais ativas, (E)-2-(butilsulfonamidometil)-3-fenilacrilato de metila e 2-[(4-clorofenil-sulfonamido)(fenil)metil]acrilato de metila, inibiram o crescimento de C. acutatum em 54 e 51%, respectivamente, na concentração de 1,5 mmol.L-1. As alilsulfonamidas foram, na maioria dos casos, mais ativas que as respectivas sulfonamidas primárias precursoras, sendo algumas destas inativas. Tais resultados sugerem que o caráter lipofílico associado ao valor de logP para cada composto é importante para a atividade antifúngica, visto que para todas as alilsulfonamidas os valores de logP foram superiores aos das sulfonamidas precursoras. Foi possível determinar o parâmetro IC 50 para o aduto 2 e para o brometo 3, correspondendo a 2,24 e 0,34 mmol.L -1, respectivamente. O composto 3 apresentou a atividade antifúngica mais promissora de todos os compostos testados, inibindo 100% do crescimento micelial de C. acutatum na concentração de 0,45 mmol.L -1, com uma atividade comparável à do fungicida comercial Mancozeb (valores de IC50 próximos), em ensaios biológicos in vitro. / This work describes the synthesis, characterization, and evaluation of the antifungal activity of eighteen allyl-sulfonamides, six primary sulfonamides, and two synthetic intermediates. The first step of the synthesis occurred via Morita- Baylis-Hillman reaction with the coupling between benzaldehyde and methyl acrylate, under trimethylamine catalysis, using methanol as solvent. The resulting adduct, methyl 2-[hydroxy(phenyl)methyl]acrylate (2), was dehydrated and converted into methyl (Z)-2-(bromomethyl)-3-(phenyl)acrylate (3) by the reaction with lithium bromide and sulfuric acid in acetonitrile. Nine allyl- sulfonamides with internal C=C double bond were synthesized from the bromide 3 in reaction with nine different primary sulfonamides and potassium carbonate using acetone as a solvent, under heating. One allyl-sulfonamide with internal C=C double bond C = C (6e) was synthesized by the reaction between the adduct 2 and 4-nitrobenzenesulfonamide in 1,2-dichloroethane, catalysed by sulfuric acid, under heating. Eight allyl-sulfonamides with internal C=C double bond were synthesized by the reaction of the compound 3 with DABCO in acetonitrile, followed by the addition of potassium carbonate and the appropriate sulfonamide to the reaction mixture. Four primary sulfonamides employed in the synthesis are commercially available. The remaining six sulfonamides were prepared from their respective sulfonyl chlorides in reaction with concentrated ammonia solution, under reflux. The adduct 2, the bromide 3 and the primary sulfonamides synthesized were characterized by their melting points and by infrared spectroscopy, in comparison with published data. The new allyl-sulfonamides with general formulae PhCH=C(COOMe)G (where G = - NHSO2Me, -NHSO2Et, -NHSO2Bu, NHSO2PhCl, -NHSO2PhBr, -NHSO2Oct, -NHSO2Ph, -NHSO2PhF, - -NHSO2PhI, -NHSO2PhNO2) and PhCH(G)C(COOMe)=CH2 (where G = -NHSO2Et, -NHSO2Bu, -NHSO2Oct, - NHSO2PhF, -NHSO2PhCl, -NHSO2PhBr, -NHSO2PhI, -NHSO2PhNO2) were characterized by the previously mentioned techniques, and by high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR) of 1H and 13 C. The infrared spectra allowed the identification of some chemical bonds and functional groups of the unpublished compounds. The NMR spectra of 1H and 13 C showed the number of signals, multiplicities and chemical shifts compatible with the proposed structures. The molecular formulae suggested for each compound were confirmed by the HR-ESI-MS spectra. All the synthesized compounds had their antifungal activity evaluated against Colletotrichum acutatum. The most active allyl-sulfonamides, methyl(E)- 2-(butylsulfonamidomethyl)-3-phenylacrilateand methyl 2-[(4- chlorophenylsulfonamido)(phenyl)methyl]acrilate, inhibited the growth of C. acutatum in 54 and 51%, respectively, at the concentration of 1,5 mmol.L -1. Almost allallyl-sulfonamides were more active than the parent primary sulfonamides, some of which were inactive. As the allyl-sulfonamides presented higher logP values than their respective precursors, these results suggested that the greater lipophilic character of the allyl-sulfonamides is important for their antifungal activity. It was possible to determine the IC 50 values for the adduct 2 and the bromide 3, which corresponded to 2,24 and 0,34 mmol.L-1, respectively. The compound 3 exhibited the most promising antifungal activity of all tested compounds, showing 100% of inhibition of the mycelial growth of C. acutatum at 0,45 mmol.L-1, with an in vitro IC50 value close to the value for the commercial fungicide Mancozeb.

This diploma thesis concentrates on testing the efficiency of antifungal and biological agents against fungal pathogens Colletotrichum acutatum and Fusarium culmorum. Five single-component antifungal agents were used for the testing and the sizes of the inhibition zones were evaluated. It was found out that the sensitivity of the pathogens to the agents varies. Most effective against Colletotrichum acutatum was the azoxystrobin compound in the Ortiva agent, whereas against Fusarium culmorum it was the Horizon agent with the active compound tebuconazole. With the biological agents, the zone of mycoparasitism was evaluated and the effect of the agents on the growth of the phytopathogenic fungi mycelia was analysed. Trichoderma harzianum exhibited better ability to colonize and suppress the growth of the pathogens‘ mycelia than Pythium oligandrum.

Ripe rot of grape is caused by two fungal species complexes: <i>Colletotrichum gloeosporioides</i> and <i>C. acutatum</i>, both of which cause disease on a variety of crops, such as strawberry and apple. To investigate effect of cultivar and cluster developmental stage on the development of ripe rot, controlled environment and field studies were conducted during 2013-2014. We have identified that a certain level of infection could can take place on most cultivars tested from bloom to the near harvest. In most of the cases, significant cultivar and cluster developmental stage interaction effects were observed (<i>P</i> < 0.05) for the development of disease symptoms in both studies. In general, susceptible cultivar (Cabernet Franc, Cabernet sauvignon, and Chardonnay) demonstrated fluctuations of disease susceptibility among cluster development stages, while resistant cultivars (Merlot) showed consistently low level of the disease throughout the season. To investigate the effect of eleven ten modes of action for control of <i>C. gloeosporioides</i> and <i>C. acutatum</i>, two methods, alamarBlue® assay and inoculation on fungicide-treated detached fruits, were used. Protective fungicides (mancozeb, captan, and copper) as well as some of newer formulations such as azoxystrobin and tetraconazole were identified as excellent products against ripe rot of grape. Four additional materials were identified as good potential candidates to investigate further. The information gained from these studies will help growers to determine the critical period for ripe rot management and chemicals to be applied for management. With better control of cluster rot pathogens, Virginia growers can experience an increase in yield and wine quality. / Master of Science in Life Sciences