11 |
Antifungal activity of essential oils associated with edible coatings for the postharvest control of spoilage fungi in strawberry (Fragaria spp.) / Atividade antifúngica de óleos essenciais associados a recobrimentos comestíveis para o controle pós-colheita de fungos deterioradores do morango (Fragaria spp.)Oliveira, Jacqueline de 05 February 2019 (has links)
Strawberry cultivation presents as limiting problem the phytosanitary management, which, associated with the residues of the toxic fungicides, the resistance of pathogens and the fragility of the fruit during transport and storage, make the commercialization of this product a challenge. The identification and development of new products with antifungal action, such as essential oils (EOs), is a promising alternative. Therefore, the present study addresses: the in vitro antifungal activity of three essential oils, Eucalyptus staigeriana, Lippia sidoides and Pimenta pseudocaryophyllus; the chemical composition and the mode of action of the EO with the highest potential and its in vivo activity when associated with carboxymethylcellulose (CMC), as well as its effects on the sensory quality and postharvest of strawberries. In chapters two, three and four, the studies were directed to Colletotrichum acutatum, Rhizopus stolonifer and Botrytis cinerea, respectively. In the last chapter, the antifungal activity of a commercial, alternative formulation with low toxicity was evaluated against the same three pathogens. Among the EOs evaluated, the one from L. sidoides presented the best antifungal activity, with the predominance of thymol in its composition, causing morphological alterations in the pathogens. in vivo, the strawberries treated with CMC associated to the EO presented a reduction in the severity of the diseases and improvements in the physicochemical properties with little alteration in the sensory quality of the fruit. The commercial formulation also presented a potential for the control, in vitro and in vivo, of the main postharvest strawberry-deteriorating fungi. / A cultura do morangueiro tem como problemática limitante o manejo fitossanitário, o que associado aos resíduos dos fungicidas tóxicos, à resistência dos patógenos e à fragilidade dos frutos durante o transporte e armazenamento, tornam a comercialização deste produto um desafio. A identificação e o desenvolvimento de novos produtos com ação antifúngica, como óleos essenciais (OEs), é uma alternativa promissora. Assim, o presente estudo discute: a atividade antifúngica in vitro de três óleos essenciais, Eucalyptus staigeriana, Lippia sidoides e Pimenta pseudocaryophyllus; a composição química e o modo de ação do OE de maior potencial e sua atividade in vivo quando associado com carboximetilcelulose (CMC), assim como seus efeitos na qualidade sensorial e pós-colheita dos morangos. Nos capítulos dois, três e quatro os estudos foram direcionados para Colletotrichum acutatum, Rhizopus stolonifer e Botrytis cinerea, respectivamente. No último capítulo avaliou-se a atividade antifúngica de uma formulação comercial, alternativa e de baixa toxidez contra os mesmos três patógenos. Dentre os OEs avaliados, o de L. sidoides apresentou melhor atividade antifúngica, com a predominância do timol em sua composição, causando alterações morfológicas nos patógenos. in vivo, os morangos tratados com CMC associado ao OE apresentaram redução na severidade das doenças e melhorias nas propriedades físico-químicas com pouca alteração na qualidade sensorial da fruta. A formulação comercial também apresentou potencial de controle, in vitro e in vivo, dos principais fungos deteriorantes pós-coheita do morango.
|
12 |
Controle químico de Colletotrichum acutatum agente causal da queda prematura dos frutos cítricosRinaldo, Davi [UNESP] 01 October 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:31Z (GMT). No. of bitstreams: 0
Previous issue date: 2010-10-01Bitstream added on 2014-06-13T20:37:30Z : No. of bitstreams: 1
rinaldo_d_me_jabo.pdf: 315574 bytes, checksum: 39e42659f57f8c9f9b87dc45b848c015 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A “queda prematura dos frutos cítricos” é causada pelo fungo Colletotrichum acutatum. O controle eficiente da doença baseia-se na pulverização com fungicidas na época da florada. Esta é considerada a principal doença fúngica do sudoeste paulista, para tanto o trabalho foi instalado em pomar comercial na cidade de Santa Cruz do Rio Pardo / SP, e teve por finalidade avaliar a eficiência de algumas misturas formuladas de fungicidas, adicionados ou não com Cloreto de Benzalcônio (CB). Utilizou-se os seguintes tratamentos: T1) tratamento testemunha; T2) CB 10g ia/100L; T3) CB 5g ia/100L; T4) Famoxadona+Mancozebe (FA + MA) 6,25+625 g ia/100L; T5) FA + MA + CB 6,25+62,5+10 g ia/100L; T6) Carbendazim (CA) 50 g ia/100L; T7) CA + CB 50+5 g ia/100L; T8) CA + CB 50+10 g ia/100L; T9) Fenilpiridinilamina (FE) 25 g ia/100L; T10) FE + CB 25+10 g ia/100L; T11) Trifloxistrobina+Tebuconazol (TR + TE) 4+8 g ia/100L; T12) TR + TE + CB 4+8+10 g ia/100L; T13) 1ª aplicação foi usado Difenoconazol 6,25 g ia/100L e nas três subseqüentes foi utilizado Carbendazim 50 g ia/100L, Convencional da fazenda (CF) + CB 10g ia/100L em todas aplicações; T14) CF. Os tratamentos foram compostos de 4 aplicações, nos estádios de “cabeça de alfinete”, “cotonete”, flor aberta e ¾ de queda de pétalas, as avaliações foram feitas medindo a quantidade de flores com sintomas, numero médio efetivo de frutos e produtividade mediante a contagem dos frutos na colheita. Os tratamentos T11 e T12 mostraram-se os mais eficientes no controle da doença, já os tratamentos compostos por Cloreto de Benzalcônio não foram eficiente quando aplicados isoladamente e quando misturados para os tratamentos (T5; T12; T13;) embora não haja diferença estatística significativa proporcionou um acréscimo em produtividade fazendo-se necessário a realização de estudos complementares / The postbloom fruit drop (PFC) is caused by Colletotrichum acutatum. Fungicide application during bloom is the main measure of control. PFC is considered the main fungal disease of the southwest of Sao Paulo State, for both the work was installed in a commercial orchard in Santa Cruz do Rio Pardo and aimed at evaluating the efficiency of fungicides formulated mixtures, added or not with benzalkonium chloride (BC). The treatment utilized were:T1) control; T2) - BC 10g ia/100L; T3) BC 5g ia/100L; T4) famaxodone + mancozeb (FA + MA) 6.25 + 625g ia/100L; T5) FA + MA + (BC) 62.5 + 6.25 + 10g ia/100L; T6) carbendazim (CA) 50g ia/100L; T7) CA + BC 50 + 5g ia/100L; T8) CA + BC 50 + 10g ia/100L; T9) phenylpyridinamine (PH) 25g ia/100L; T10) PH + BC 25 + 10g ia/100L, T-11 trifloxystrobin + tebuconazol (TR + TE) 4 + 8g ia/100L; T12) TR + TE + BC 4 + 8 + 10g ia/100L; T13) first application with difenoconazol 6.25g ia/100L, and three application subsequent carbendazim 50g ia/100L. Conventional farm application (CF) added with BC 10g ia/100L in all applications; T14) BC. The treatments consisted of 4 applications, in stages of pin head, ‘hollow ball’, and flowers open and ¾ of petal fall, the assessments were made by measuring the amount of flowers with symptoms, effectives average number of fruits and number of fruit at harvest. The treatments T11 and T12 were the most effective for disease control, the treatments with benzalkonium chloride not provided efficient when applied alone or in mixture in tank with the treatments (T5; T12; T13), although not observed difference significant, provided a increased productivity, necessity studies complements
|
13 |
Isolamento, caracterização e avaliação da atividade fotossensibilizadora de cumarinas e furanocumarinas extraídas de espécies de Citrus / Isolation, characterization and evaluation of photosensitizer activity of coumarins and furocoumarins extracted from Citrus speciesFracarolli, Letícia 23 September 2015 (has links)
O crescente aumento da tolerância aos fungicidas atualmente utilizados é um dos principais problemas tanto na área clínica quanto na agrícola e tem estimulado o desenvolvimento de estratégias alternativas para o controle de fungos patogênicos, tais como o tratamento fotodinâmico antimicrobiano (TFA), que pode utilizar fotossensibilizadores (FS) de origem natural ou sintética. Alguns FS, como as cumarinas e furanocumarinas, são produzidos por espécies de Citrus como limão Tahiti (Citrus latifolia) e toranjas (Citrus paradisi). O presente estudo investigou o TFA in vitro de conídios do fungo fitopatogênico Colletotrichum acutatum com: (1) o corante fenotiazínico azul de metileno (MB), (2) uma furanocumarina comercial, 8-metoxipsoraleno (8-MOP), (3) uma cumarina comercial, (2H-chromen-2-one), (4) a cumarina 5,7-dimetoxicumarina extraída no presente trabalho a partir de óleo da casca do limão Tahiti, (5) a cumarina 7-hidroxicumarina extraída no presente trabalho a partir de óleo essencial de toranja rubi, (6) duas frações extraídas por De Menezes e colaboradores (2014a) a partir de um resíduo da indústria citrícola, uma delas constituída pela furanocumarina isopimpinelina e outra constituída por uma mistura das cumarinas 7-metoxicumarina e 5,7-dimetoxicumarina (3:1), (7) cinco extratos brutos obtidos a partir de óleos da casca e essencial de limão Tahiti e óleos essenciais de toranjas rubi e branca. Com exceção do extrato bruto obtido do óleo essencial de toranja branca, todos os demais extratos apresentaram cumarinas e/ou furanocumarinas em sua composição. As suspensões de conídios foram tratadas com os diferentes compostos (50 ?M para os compostos comerciais e as frações puras e 12,5 mg L-1 para os extratos e a mistura) e expostas à radiação solar por 1 h. O MB foi exposto à radiação solar por 30 min, 1 e 2 h. Determinou-se o efeito do tratamento fotodinâmico em folhas de mudas de laranja Valencia (Citrus sinensis) com (1) 8-MOP, (2) mistura de cumarinas, (3) 5,7-dimetoxicumarina e (4) o extrato bruto de limão Tahiti. Adicionalmente, experimentos para avaliar a estabilidade do 8-MOP exposto à radiação solar por até 12 h foram realizados. Nesses experimentos, soluções de 8-MOP (50 ?M) foram expostas à radiação solar e alíquotas foram retiradas após os diferentes tempos de exposição. Após as exposições, estudos de espectroscopia de absorção no UV e emissão de fluorescência foram realizados, além da realização de experimentos para avaliar a eficácia do TFA com os FS previamente expostos à radiação solar por 6 e 12 h. Os TFA mais eficazes foram com o MB, 8-MOP (ambos 50 ?M), a mistura de cumarinas e um dos extratos brutos obtidos de limão Tahiti (ambos 12,5 mg L-1), que mataram 99,998%, 99,378%, 99,336% e 65,049% dos conídios, respectivamente, após 1 h de exposição à radiação solar. Nenhum dano nas folhas de laranja foi observado após o TFA com os compostos. Os espectros de absorção e emissão de fluorescência das soluções de 8-MOP expostas à radiação solar mostraram fotodegradação do composto após 12 h de exposição. Entretanto, as soluções de 8-MOP expostas por 6 e por 12 h ainda foram capazes de matar 99,978% e 95,591% dos conídios de C. acutatum, respectivamente / Increasing tolerance to currently used fungicides is a major problem both in clinical and agricultural areas and has stimulated the development of alternative strategies to control pathogenic fungi such as the antimicrobial photodynamic treatment (APDT), that can use natural or synthetic photosensitizers (PS). Some PS, such as coumarins and furocoumarins are produced by Citrus species such Tahiti acid lime (Citrus latifolia) and grapefruit (Citrus paradisi). This study investigated the in vitro APDT of conidia of the plant-pathogenic fungi C. acutatum with: (1) the phenothiazinium dye methylene blue (MB), (2) commercial furocoumarin, 8-methoxypsoralen (8-MOP), (3) commercial coumarin (2H-chromen-2-one), (4) coumarin 5,7-dimethoxycoumarin, extracted in this study from Tahiti lime peel oil, (5) coumarin 7-hidroxycoumarina, extracted in this study from ruby grapefruit essential oil, (6) two fractions extracted by De Menezes et al (2014a) from a Citrus industry residue, one of them constituted by the furocoumarin isopimpinellin, and the other constituted by the mixture of coumarins 7-methoxycoumarin and 5,7-dimethoxycoumarin (3:1), (7) five crude extracts obtained from Tahiti lime peel or essential oil and ruby and white grapefruit essential oil. Except the extract from the white grapefruit, all the others presented coumarins and/or furocoumarins in their composition. Conidial suspentions were treated with the different PS (50 ?M for commercial and pure compounds and 12.5 mg L-1 for the extracts and the mixture) and exposed to solar radiation for 1 h. The MB was exposed to solar radiation for 30 min, 1 and 2 h. The APDT effect on the leaves of Valencia orange trees (Citrus sinensis) with (1) 8-MOP, (2) the mixture of coumarins, (3) 5,7-dimethoxycoumarin, and (4) the most efective extract from Tahiti lime were determined. Additionally, experiments to assess the 8-MOP stability after exposure to solar radiation for 12 h were realized. 8-MOP solutions (50 ?M) were exposed under solar radiation and rates were removed after different times of exposition. After the expositions, absorption spectroscopic studies in UV and fluorescence emission were realized, as well as holding the realization of experiments of APDT efficacy evaluation after 6 and 12 h to exposure under solar radiation. The more effective treatments were with MB, 8-MOP (both 50 ?M), the coumarins mixture and one of the extracts from Tahiti lime (both 12.5 mg L-1), killing at least 99,998%, 99,378%, 99,336% and 65,049% of the conidia, respectively after 1 h under solar radiation. No damage to orange tree leaves was observed after APDT with any of the compounds. The absorption and fluorescence intensity spectra showed the 8-MOP photodegradation after 12 h of exposition, although the 8-MOP solutions exposed under solar radiation for 6 and 12 h still killed at least 99,978% and 95,591% of the C. acutatum conidia, respectively
|
14 |
Inativação fotodinâmica de conídios dos fungos Aspergillus nidulans, Colletotrichum acutatum e Colletotrichum gloeosporioides com fotossensibilizadores fenotiazínicos e cumarínicos / Photodynamic inactivation of conidia of the fungi Aspergillus nidulans, Colletotrichum acutatum and Colletotrichum gloeosporioides with phenothiazinium and coumarinium photosensitizersMenezes, Henrique Dantas de 29 August 2012 (has links)
O tratamento fotodinâmico antifúngico (APDT) é um método promissor que combina um fotossensibilizador não tóxico (FS), oxigênio e luz visível para provocar a morte seletiva das células microbianas. O desenvolvimento do APDT depende da identificação de FS que sejam eficazes para as diferentes espécies de patógenos. No presente estudo, as suscetibilidades, in vitro, de conídios de Colletotrichum acutatum, C. gloeosporioides (ambas são espécies fitopatogênicas) e Aspergillus nidulans ao APDT com quatro FS fenotiazínicos [azul de metileno (MB), novo azul de metileno N (NMBN), azul de toluidina O (TBO) e o novo fenotiazínico pentacíclico S137 (S137)] em combinação com a luz vermelha, foram investigadas. Nós também avaliamos a suscetibilidade dos conídios de C. acutatum e A. nidulans ao APDT com o psoraleno 8-metóxipsoraleno (8-MOP), com duas cumarinas (7- metoxicumarina e 5,7-dimetóxicumarina) e com uma furanocumarina (isopimpinelina) em combinação com a radiação solar. Ambas as cumarinas e a furanocumarinas foram extraídas, no presente trabalho, do limão Tahiti (Citrus latifolia). Os efeitos dos tratamentos com os diferentes FS nas folhas de laranja-pera (Citrus sinensis) também foram avaliados. O NMBN e o S137 foram os fenotiazínicos mais eficazes. Os APDT com o NMBN (50 ?M) e S137 (10 ?M) e dose de luz de 25 J cm-2 resultaram na redução de aproximadamente 5 logs na sobrevivência dos conídios das três espécies. O APDT com o 8-MOP e com as cumarinas resultaram em uma redução de aproximadamente 4 logs na sobrevivência dos conídios de C. acutatum e A. nidulans. O APDT com a furanocumarina foi menos efetivo e resultou em uma redução na sobrevivência dos conídios de aproximadamente dois logs para C. acutatum e de três logs para A. nidulans. Nenhum dano nas folhas foi observado quando os FS foram colocados na superfície adaxial das folhas. Os estudos histológicos mostraram que nenhum dos FS fenotiazínicos atravessou a cutícula das folhas. / Antifungal photodynamic treatment (APDT) is a promising method that combines a nontoxic photosensitizer (PS), oxygen and visible light to cause selective killing of microbial cells. The development of APDT depends on identifying effective PS for the different pathogenic species. In the present study, the in vitro susceptibilities of Colletotrichum acutatum, C. gloeosporioides (both are phytophatogenic species) and Aspergillus nidulans conidia to APDT with four phenothiazinium PS [methylene blue (MB), new methylene blue N (NMBN), toluidine blue O (TBO) and the novel pentacicyclic phenothiazinium S137 (S137)] in combination with red light were investigated. We also evaluated the susceptibilities of C. acutatum and A. nidulans conidia to APDT with the psoralen 8-methoxypsoralen (8-MOP), with two coumarins (7-methoxicoumarin and 5,7-dimethoxycoumarin) and one furanocoumarin (isopimpinelin) in combination with solar radiation. Both the coumarins and the furanocoumarin were extracted, in the present work, from Tahiti lemon (Citrus latifolia). The effects of the treatments with all the PS on Citrus sinensis leaves were also evaluated. NMBN and S137 were the more effective phenothiazinium PS. APDT with NMBN (50 ?M) and S137 (10 ?M) and light dose of 25 J cm-2 resulted in a reduction of approximately 5 logs in the survival of the conidia of the three species. APDT with 8-MOP and with the coumarins resulted in a reduction of approximately 4 logs in the survival of C. acutatum and A. nidulans conidia. APDT with the furanocumarin was less effective and resulted in the reduction of approximately 2 logs for C. acutatum and 3 logs for A. nidulans. No damages to the leaves were observed when the PS were spotted on the adaxial surface of the leaves and the plants were exposed to solar radiation. Histological studies showed that the phenothiazinium PS did not cross the leave cuticle.
|
15 |
Inativação fotodinâmica de conídios dos fungos Aspergillus nidulans, Colletotrichum acutatum e Colletotrichum gloeosporioides com fotossensibilizadores fenotiazínicos e cumarínicos / Photodynamic inactivation of conidia of the fungi Aspergillus nidulans, Colletotrichum acutatum and Colletotrichum gloeosporioides with phenothiazinium and coumarinium photosensitizersHenrique Dantas de Menezes 29 August 2012 (has links)
O tratamento fotodinâmico antifúngico (APDT) é um método promissor que combina um fotossensibilizador não tóxico (FS), oxigênio e luz visível para provocar a morte seletiva das células microbianas. O desenvolvimento do APDT depende da identificação de FS que sejam eficazes para as diferentes espécies de patógenos. No presente estudo, as suscetibilidades, in vitro, de conídios de Colletotrichum acutatum, C. gloeosporioides (ambas são espécies fitopatogênicas) e Aspergillus nidulans ao APDT com quatro FS fenotiazínicos [azul de metileno (MB), novo azul de metileno N (NMBN), azul de toluidina O (TBO) e o novo fenotiazínico pentacíclico S137 (S137)] em combinação com a luz vermelha, foram investigadas. Nós também avaliamos a suscetibilidade dos conídios de C. acutatum e A. nidulans ao APDT com o psoraleno 8-metóxipsoraleno (8-MOP), com duas cumarinas (7- metoxicumarina e 5,7-dimetóxicumarina) e com uma furanocumarina (isopimpinelina) em combinação com a radiação solar. Ambas as cumarinas e a furanocumarinas foram extraídas, no presente trabalho, do limão Tahiti (Citrus latifolia). Os efeitos dos tratamentos com os diferentes FS nas folhas de laranja-pera (Citrus sinensis) também foram avaliados. O NMBN e o S137 foram os fenotiazínicos mais eficazes. Os APDT com o NMBN (50 ?M) e S137 (10 ?M) e dose de luz de 25 J cm-2 resultaram na redução de aproximadamente 5 logs na sobrevivência dos conídios das três espécies. O APDT com o 8-MOP e com as cumarinas resultaram em uma redução de aproximadamente 4 logs na sobrevivência dos conídios de C. acutatum e A. nidulans. O APDT com a furanocumarina foi menos efetivo e resultou em uma redução na sobrevivência dos conídios de aproximadamente dois logs para C. acutatum e de três logs para A. nidulans. Nenhum dano nas folhas foi observado quando os FS foram colocados na superfície adaxial das folhas. Os estudos histológicos mostraram que nenhum dos FS fenotiazínicos atravessou a cutícula das folhas. / Antifungal photodynamic treatment (APDT) is a promising method that combines a nontoxic photosensitizer (PS), oxygen and visible light to cause selective killing of microbial cells. The development of APDT depends on identifying effective PS for the different pathogenic species. In the present study, the in vitro susceptibilities of Colletotrichum acutatum, C. gloeosporioides (both are phytophatogenic species) and Aspergillus nidulans conidia to APDT with four phenothiazinium PS [methylene blue (MB), new methylene blue N (NMBN), toluidine blue O (TBO) and the novel pentacicyclic phenothiazinium S137 (S137)] in combination with red light were investigated. We also evaluated the susceptibilities of C. acutatum and A. nidulans conidia to APDT with the psoralen 8-methoxypsoralen (8-MOP), with two coumarins (7-methoxicoumarin and 5,7-dimethoxycoumarin) and one furanocoumarin (isopimpinelin) in combination with solar radiation. Both the coumarins and the furanocoumarin were extracted, in the present work, from Tahiti lemon (Citrus latifolia). The effects of the treatments with all the PS on Citrus sinensis leaves were also evaluated. NMBN and S137 were the more effective phenothiazinium PS. APDT with NMBN (50 ?M) and S137 (10 ?M) and light dose of 25 J cm-2 resulted in a reduction of approximately 5 logs in the survival of the conidia of the three species. APDT with 8-MOP and with the coumarins resulted in a reduction of approximately 4 logs in the survival of C. acutatum and A. nidulans conidia. APDT with the furanocumarin was less effective and resulted in the reduction of approximately 2 logs for C. acutatum and 3 logs for A. nidulans. No damages to the leaves were observed when the PS were spotted on the adaxial surface of the leaves and the plants were exposed to solar radiation. Histological studies showed that the phenothiazinium PS did not cross the leave cuticle.
|
16 |
Isolamento, caracterização e avaliação da atividade fotossensibilizadora de cumarinas e furanocumarinas extraídas de espécies de Citrus / Isolation, characterization and evaluation of photosensitizer activity of coumarins and furocoumarins extracted from Citrus speciesLetícia Fracarolli 23 September 2015 (has links)
O crescente aumento da tolerância aos fungicidas atualmente utilizados é um dos principais problemas tanto na área clínica quanto na agrícola e tem estimulado o desenvolvimento de estratégias alternativas para o controle de fungos patogênicos, tais como o tratamento fotodinâmico antimicrobiano (TFA), que pode utilizar fotossensibilizadores (FS) de origem natural ou sintética. Alguns FS, como as cumarinas e furanocumarinas, são produzidos por espécies de Citrus como limão Tahiti (Citrus latifolia) e toranjas (Citrus paradisi). O presente estudo investigou o TFA in vitro de conídios do fungo fitopatogênico Colletotrichum acutatum com: (1) o corante fenotiazínico azul de metileno (MB), (2) uma furanocumarina comercial, 8-metoxipsoraleno (8-MOP), (3) uma cumarina comercial, (2H-chromen-2-one), (4) a cumarina 5,7-dimetoxicumarina extraída no presente trabalho a partir de óleo da casca do limão Tahiti, (5) a cumarina 7-hidroxicumarina extraída no presente trabalho a partir de óleo essencial de toranja rubi, (6) duas frações extraídas por De Menezes e colaboradores (2014a) a partir de um resíduo da indústria citrícola, uma delas constituída pela furanocumarina isopimpinelina e outra constituída por uma mistura das cumarinas 7-metoxicumarina e 5,7-dimetoxicumarina (3:1), (7) cinco extratos brutos obtidos a partir de óleos da casca e essencial de limão Tahiti e óleos essenciais de toranjas rubi e branca. Com exceção do extrato bruto obtido do óleo essencial de toranja branca, todos os demais extratos apresentaram cumarinas e/ou furanocumarinas em sua composição. As suspensões de conídios foram tratadas com os diferentes compostos (50 ?M para os compostos comerciais e as frações puras e 12,5 mg L-1 para os extratos e a mistura) e expostas à radiação solar por 1 h. O MB foi exposto à radiação solar por 30 min, 1 e 2 h. Determinou-se o efeito do tratamento fotodinâmico em folhas de mudas de laranja Valencia (Citrus sinensis) com (1) 8-MOP, (2) mistura de cumarinas, (3) 5,7-dimetoxicumarina e (4) o extrato bruto de limão Tahiti. Adicionalmente, experimentos para avaliar a estabilidade do 8-MOP exposto à radiação solar por até 12 h foram realizados. Nesses experimentos, soluções de 8-MOP (50 ?M) foram expostas à radiação solar e alíquotas foram retiradas após os diferentes tempos de exposição. Após as exposições, estudos de espectroscopia de absorção no UV e emissão de fluorescência foram realizados, além da realização de experimentos para avaliar a eficácia do TFA com os FS previamente expostos à radiação solar por 6 e 12 h. Os TFA mais eficazes foram com o MB, 8-MOP (ambos 50 ?M), a mistura de cumarinas e um dos extratos brutos obtidos de limão Tahiti (ambos 12,5 mg L-1), que mataram 99,998%, 99,378%, 99,336% e 65,049% dos conídios, respectivamente, após 1 h de exposição à radiação solar. Nenhum dano nas folhas de laranja foi observado após o TFA com os compostos. Os espectros de absorção e emissão de fluorescência das soluções de 8-MOP expostas à radiação solar mostraram fotodegradação do composto após 12 h de exposição. Entretanto, as soluções de 8-MOP expostas por 6 e por 12 h ainda foram capazes de matar 99,978% e 95,591% dos conídios de C. acutatum, respectivamente / Increasing tolerance to currently used fungicides is a major problem both in clinical and agricultural areas and has stimulated the development of alternative strategies to control pathogenic fungi such as the antimicrobial photodynamic treatment (APDT), that can use natural or synthetic photosensitizers (PS). Some PS, such as coumarins and furocoumarins are produced by Citrus species such Tahiti acid lime (Citrus latifolia) and grapefruit (Citrus paradisi). This study investigated the in vitro APDT of conidia of the plant-pathogenic fungi C. acutatum with: (1) the phenothiazinium dye methylene blue (MB), (2) commercial furocoumarin, 8-methoxypsoralen (8-MOP), (3) commercial coumarin (2H-chromen-2-one), (4) coumarin 5,7-dimethoxycoumarin, extracted in this study from Tahiti lime peel oil, (5) coumarin 7-hidroxycoumarina, extracted in this study from ruby grapefruit essential oil, (6) two fractions extracted by De Menezes et al (2014a) from a Citrus industry residue, one of them constituted by the furocoumarin isopimpinellin, and the other constituted by the mixture of coumarins 7-methoxycoumarin and 5,7-dimethoxycoumarin (3:1), (7) five crude extracts obtained from Tahiti lime peel or essential oil and ruby and white grapefruit essential oil. Except the extract from the white grapefruit, all the others presented coumarins and/or furocoumarins in their composition. Conidial suspentions were treated with the different PS (50 ?M for commercial and pure compounds and 12.5 mg L-1 for the extracts and the mixture) and exposed to solar radiation for 1 h. The MB was exposed to solar radiation for 30 min, 1 and 2 h. The APDT effect on the leaves of Valencia orange trees (Citrus sinensis) with (1) 8-MOP, (2) the mixture of coumarins, (3) 5,7-dimethoxycoumarin, and (4) the most efective extract from Tahiti lime were determined. Additionally, experiments to assess the 8-MOP stability after exposure to solar radiation for 12 h were realized. 8-MOP solutions (50 ?M) were exposed under solar radiation and rates were removed after different times of exposition. After the expositions, absorption spectroscopic studies in UV and fluorescence emission were realized, as well as holding the realization of experiments of APDT efficacy evaluation after 6 and 12 h to exposure under solar radiation. The more effective treatments were with MB, 8-MOP (both 50 ?M), the coumarins mixture and one of the extracts from Tahiti lime (both 12.5 mg L-1), killing at least 99,998%, 99,378%, 99,336% and 65,049% of the conidia, respectively after 1 h under solar radiation. No damage to orange tree leaves was observed after APDT with any of the compounds. The absorption and fluorescence intensity spectra showed the 8-MOP photodegradation after 12 h of exposition, although the 8-MOP solutions exposed under solar radiation for 6 and 12 h still killed at least 99,978% and 95,591% of the C. acutatum conidia, respectively
|
17 |
Caracterização e identificação de espécies de Colletotrichum associadas à antracnose do pimentão (Capsicum annuum) no Brasil / Characterization and identification of Colletotrichum species associated to anthracnose in pepper (Capsicum annuum) in BrazilTozze Junior, Hugo Jose 01 February 2008 (has links)
A antracnose é uma das doenças mais importantes do pimentão em vários países. Por muitos anos, somente C. gloeosporioides foi relatado como agente causal da antracnose desta cultura no Brasil. Entretanto, recentemente C. acutatum e C. capsici também tem sido associados a esta doença em algumas regiões do país. Neste trabalho, 56 isolados de Colletotrichum obtidos de pimentão e procedentes de diferentes regiões produtoras do país foram caracterizados e identificados por meio de algumas características morfológicas e culturais, e pela análise por PCR utilizando oligonucleotídeos espécie-específicos. Isolados representativos de cada espécie identificada na população amostrada também foram caracterizados quanto à patogenicidade em frutos de pimentão verdes e maduros, feridos e não feridos e quanto a sensibilidade aos fungicidas azoxistrobina, carbendazim, tiabendazol, tebuconazol, captana, clorotalonil e cloreto de benzalcônio. Os resultados demonstram que C. acutatum é a espécie predominante nas principais regiões produtoras de pimentão do país, representando cerca de 72% da população amostrada. C. capsici foi encontrada com freqüência aproximada de 14%, nos estados de São Paulo e Minas Gerais. C. gloeosporioides representou apenas 5% da população amostrada e teve distribuição restrita ao estado de São Paulo e ao Distrito Federal. Um único isolado de C. coccodes foi encontrado no Rio Grande do Sul. Além dessas espécies, isolados identificados como C. boninense foram encontrados em São Paulo e no Rio Grande do Sul, com freqüência de 7% na população amostrada. Este parece ser o primeiro relato de C. boninense infectando pimentão no Brasil e em outras partes do mundo. A caracterização patogênica mostrou que isolados representativos de todas as espécies foram patogênicos aos frutos maduros feridos e não feridos. Nos frutos verdes feridos, apenas os isolados de C. acutatum e de C. capsici promoveram sintomas. Não foram observados sintomas nos frutos verdes sem ferimentos durante o período de avaliação do experimento (12 dias) para nenhum dos isolados. C. acutatum demonstrou ser a espécie mais agressiva, apresentando os menores períodos de latência e a maior esporulação tanto em frutos verdes (feridos) como nos maduros (feridos e não feridos). Os isolados pertencentes a diferentes espécies de Colletotrichum apresentaram sensibilidade diferenciada para todos os fungicidas sistêmicos avaliados. Os isolados de C. acutatum foram mais sensíveis a azoxistrobina, enquanto os isolados de C. gloeosporioides demonstraram a menor sensibilidade para este fungicida. Os isolados de C. gloeosporioides e C. boninense foram os mais sensíveis aos benzimidazóis (carbendazim e tiabendazol), enquanto o isolado de C. coccodes teve a menor sensibilidade para estes fungicidas. O fungicida tebuconazol promoveu o maior controle sobre o crescimento micelial dos isolados. Para este fungicida, C. capsici demonstrou ser a espécie menos sensível. Os resultados deste trabalho demonstram a presença de pelo menos cinco espécies de Colletotrichum responsáveis pela antracnose do pimentão no país e evidenciam a presença de importantes diferenças entre essas, que devem ser consideradas durante o manejo da doença. / In several countries, anthracnose is one of the most serious diseases in pepper. C. gloeosporioides has, for many years, been reported as the causal agent of anthracnose in Brazil. C. acutatum and C. capsici have only recently been reported as agents of anthracnose in some regions of the country. In this study, 56 isolates of Colletotrichum obtained from pepper from different areas of the country were characterized and identified based on the morphological characteristics of the conidia, as well as culture characteristics and PCR analysis with species-specific pairs of primers. Isolates representative of each identified species in the sampled population were also characterized according to their pathogenicity in pepper fruits (unripe, ripe, wounded and nonwounded) and also according to their sensitivity to fungicide (azoxystrobin, carbendazim, thiabendazole, tebuconazole, captan, chlorothalonil and benzalkonium chloride). The results have showed that C. acutatum is the most prevalent species found in the main production areas of pepper, present in about 72% of the sampled population. C. capsici was equivalent to 14% of the sampled population and found in the states of São Paulo and Minas Gerais. C. gloeosporioides was present in only 5% of the samples and it was restricted to the state of São Paulo and Distrito Federal. Only one isolate of C. coccodes was found in Rio Grande do Sul. Besides theses species, isolates of C. boninense were found in São Paulo and Rio Grande do Sul, with an occurrence of 7% in the sampled population. This seems to be the first report of C. boninense infecting pepper in Brazil and other parts of the world. The pathogenic characterization showed that representative isolates of all species were pathogenic in ripe, wounded, or nonwounded fruits. In wounded green fruit, only isolates of C. acutatum and C. capsici caused infection resulting in disease symptoms. No disease symptoms were observed in green nonwounded fruits inoculated with all Colletotrichum isolates, after 12 days of inoculation. C. acutatum was the most aggressive species with the shortest periods of latency and the highest rate of sporulation in either green wounded fruits or ripe fruits (wounded and nonwounded). Isolates of different species of Colletotrichum showed different sensitivity to the systemic fungicides evaluated. The isolates of C. acutatum were more sensitive to azoxystrobin, whereas C. gloeosporioides showed the lowest sensitivity to this fungicide. C. gloeosporioides and C. boninense isolates were the most sensitive to benzimidazoles fungicides (carbendazim and thiabendazole), whereas C. coccodes isolates showed the lowest sensitivity to these fungicides. The tebuconazol fungicide exerted the highest effect on mycelial growth for all Colletotrichum species. C. capsici showed to be less sensitive to this fungicide. The results of this work have shown the presence of at least five species of Colletotrichum responsible for anthracnose in pepper in Brazil and have made evident the importance of the differences between these species, which must be taken into account for the control of the disease.
|
18 |
Approaches to Species Delineation in Anamorphic (mitosporic) Fungi: A Study on Two Extreme CasesVinnere, Olga January 2004 (has links)
<p>Since the beginning of mycology, studies of species concept in fungi have been mainly based on morphology, partially due to the history of mycology as part of botany. Current advances in biochemical and molecular research have provided mycologists with powerful tools that can be used for delineation of fungal taxa. Recently, an integrated approach to fungal taxonomy involving both morphological and molecular traits has found a wide application for identification of species, especially in anamorphic (mitosporic) fungi.</p><p>In this thesis, I have tried to use this approach for identification of species units in two rather unrelated groups of organisms. One of the case studies concerned <i>Colletotrichum acutatum</i> – a worldwide economically important plant pathogenic anamorphic fungus, which is exhibiting a high level of variation in both morphological and molecular features. This fungus has been intensively studied during the past decades, and several attempts have been made to find reliable markers to separate it from other closely related species of <i>Colletotrichum</i>. The second case studied in this thesis was <i>Mycelia Sterilia</i> – an artificial group of fungi, which are deficient in production of spores of any kind, therefore lacking the main morphological feature used for assigning them to any certain fungal taxon below class level. Due to this peculiarity, <i>Mycelia Sterilia</i> have usually been neglected, and currently there is no working species concept applicable to these fungi. </p><p>In this work, I have tried to clarify the relationships among <i>C. acutatum</i> and several other anamorphic (<i>C. gloeosporioides</i> and <i>C. fructigenum</i>) and teleomorphic (<i>Glomerella acutata</i>, <i>G. cingulata</i> and <i>G. miyabeana</i>) taxa that are closely related to each other. For this purpose, examination of morphological traits was employed in combination with comparison of DNA sequencing data from three loci and subsequent phylogenetic analysis. As a result, re-description of <i>C. acutatum</i> and separation of (at least) two new species was proposed.</p><p>For studies of <i>Mycelia Sterilia</i>, a large collection of sterile strains was screened in search for biologically interesting organisms. One novel pathogen has been found, and two plant growth promoting strains with antifungal properties were selected. Attempt for tentative identification of those fungi was made based on their morphological, physiological and molecular features. Sequencing of several genes and spacers of the ribosomal DNA array revealed that the plant pathogenic strain is closely related to the teleomorphic basidiomycete genus <i>Campanella</i>, and plant growth-promoting isolates were identified as belonging to the anamorphic ascomycete genus <i>Phoma</i>. However, assigning the sterile strains to any existing species was not possible.</p><p>The main conclusion of the thesis is that species in anamorphic fungi should be defined based on a combination of morphological and molecular methods, both equally important, involving as many aspects of fungal biology as is possible at our current state of knowledge. </p>
|
19 |
Approaches to Species Delineation in Anamorphic (mitosporic) Fungi : A Study on Two Extreme CasesVinnere, Olga January 2004 (has links)
Since the beginning of mycology, studies of species concept in fungi have been mainly based on morphology, partially due to the history of mycology as part of botany. Current advances in biochemical and molecular research have provided mycologists with powerful tools that can be used for delineation of fungal taxa. Recently, an integrated approach to fungal taxonomy involving both morphological and molecular traits has found a wide application for identification of species, especially in anamorphic (mitosporic) fungi. In this thesis, I have tried to use this approach for identification of species units in two rather unrelated groups of organisms. One of the case studies concerned Colletotrichum acutatum – a worldwide economically important plant pathogenic anamorphic fungus, which is exhibiting a high level of variation in both morphological and molecular features. This fungus has been intensively studied during the past decades, and several attempts have been made to find reliable markers to separate it from other closely related species of Colletotrichum. The second case studied in this thesis was Mycelia Sterilia – an artificial group of fungi, which are deficient in production of spores of any kind, therefore lacking the main morphological feature used for assigning them to any certain fungal taxon below class level. Due to this peculiarity, Mycelia Sterilia have usually been neglected, and currently there is no working species concept applicable to these fungi. In this work, I have tried to clarify the relationships among C. acutatum and several other anamorphic (C. gloeosporioides and C. fructigenum) and teleomorphic (Glomerella acutata, G. cingulata and G. miyabeana) taxa that are closely related to each other. For this purpose, examination of morphological traits was employed in combination with comparison of DNA sequencing data from three loci and subsequent phylogenetic analysis. As a result, re-description of C. acutatum and separation of (at least) two new species was proposed. For studies of Mycelia Sterilia, a large collection of sterile strains was screened in search for biologically interesting organisms. One novel pathogen has been found, and two plant growth promoting strains with antifungal properties were selected. Attempt for tentative identification of those fungi was made based on their morphological, physiological and molecular features. Sequencing of several genes and spacers of the ribosomal DNA array revealed that the plant pathogenic strain is closely related to the teleomorphic basidiomycete genus Campanella, and plant growth-promoting isolates were identified as belonging to the anamorphic ascomycete genus Phoma. However, assigning the sterile strains to any existing species was not possible. The main conclusion of the thesis is that species in anamorphic fungi should be defined based on a combination of morphological and molecular methods, both equally important, involving as many aspects of fungal biology as is possible at our current state of knowledge.
|
20 |
Controle químico de Colletotrichum acutatum agente causal da queda prematura dos frutos cítricos /Rinaldo, Davi. January 2010 (has links)
Resumo: A "queda prematura dos frutos cítricos" é causada pelo fungo Colletotrichum acutatum. O controle eficiente da doença baseia-se na pulverização com fungicidas na época da florada. Esta é considerada a principal doença fúngica do sudoeste paulista, para tanto o trabalho foi instalado em pomar comercial na cidade de Santa Cruz do Rio Pardo / SP, e teve por finalidade avaliar a eficiência de algumas misturas formuladas de fungicidas, adicionados ou não com Cloreto de Benzalcônio (CB). Utilizou-se os seguintes tratamentos: T1) tratamento testemunha; T2) CB 10g ia/100L; T3) CB 5g ia/100L; T4) Famoxadona+Mancozebe (FA + MA) 6,25+625 g ia/100L; T5) FA + MA + CB 6,25+62,5+10 g ia/100L; T6) Carbendazim (CA) 50 g ia/100L; T7) CA + CB 50+5 g ia/100L; T8) CA + CB 50+10 g ia/100L; T9) Fenilpiridinilamina (FE) 25 g ia/100L; T10) FE + CB 25+10 g ia/100L; T11) Trifloxistrobina+Tebuconazol (TR + TE) 4+8 g ia/100L; T12) TR + TE + CB 4+8+10 g ia/100L; T13) 1ª aplicação foi usado Difenoconazol 6,25 g ia/100L e nas três subseqüentes foi utilizado Carbendazim 50 g ia/100L, Convencional da fazenda (CF) + CB 10g ia/100L em todas aplicações; T14) CF. Os tratamentos foram compostos de 4 aplicações, nos estádios de "cabeça de alfinete", "cotonete", flor aberta e ¾ de queda de pétalas, as avaliações foram feitas medindo a quantidade de flores com sintomas, numero médio efetivo de frutos e produtividade mediante a contagem dos frutos na colheita. Os tratamentos T11 e T12 mostraram-se os mais eficientes no controle da doença, já os tratamentos compostos por Cloreto de Benzalcônio não foram eficiente quando aplicados isoladamente e quando misturados para os tratamentos (T5; T12; T13;) embora não haja diferença estatística significativa proporcionou um acréscimo em produtividade fazendo-se necessário a realização de estudos complementares / Abstract: The postbloom fruit drop (PFC) is caused by Colletotrichum acutatum. Fungicide application during bloom is the main measure of control. PFC is considered the main fungal disease of the southwest of Sao Paulo State, for both the work was installed in a commercial orchard in Santa Cruz do Rio Pardo and aimed at evaluating the efficiency of fungicides formulated mixtures, added or not with benzalkonium chloride (BC). The treatment utilized were:T1) control; T2) - BC 10g ia/100L; T3) BC 5g ia/100L; T4) famaxodone + mancozeb (FA + MA) 6.25 + 625g ia/100L; T5) FA + MA + (BC) 62.5 + 6.25 + 10g ia/100L; T6) carbendazim (CA) 50g ia/100L; T7) CA + BC 50 + 5g ia/100L; T8) CA + BC 50 + 10g ia/100L; T9) phenylpyridinamine (PH) 25g ia/100L; T10) PH + BC 25 + 10g ia/100L, T-11 trifloxystrobin + tebuconazol (TR + TE) 4 + 8g ia/100L; T12) TR + TE + BC 4 + 8 + 10g ia/100L; T13) first application with difenoconazol 6.25g ia/100L, and three application subsequent carbendazim 50g ia/100L. Conventional farm application (CF) added with BC 10g ia/100L in all applications; T14) BC. The treatments consisted of 4 applications, in stages of pin head, 'hollow ball', and flowers open and ¾ of petal fall, the assessments were made by measuring the amount of flowers with symptoms, effectives average number of fruits and number of fruit at harvest. The treatments T11 and T12 were the most effective for disease control, the treatments with benzalkonium chloride not provided efficient when applied alone or in mixture in tank with the treatments (T5; T12; T13), although not observed difference significant, provided a increased productivity, necessity studies complements / Orientador: Antonio de Goes / Coorientador: Ricardo Braga Baldassari / Banca: Renato Ferrari dos Reis / Banca: Rita de Cássia Panizzi / Mestre
|
Page generated in 0.063 seconds