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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

EFECTO in vitro Y EN INVERNADERO DE CEPAS MEJORADAS DE Trichoderma spp. EN EL CONTROL DE Rhizoctonia solani (Kühn)

Ochoa Antileo, Fabián Andrés January 2008 (has links)
Memoria para optar al título profesional de: Ingeniero Agrónomo Mención: Sanidad Vegetal / El presente trabajo tuvo como objetivo determinar la capacidad biocontroladora de cepas mejoradas de Trichoderma spp. obtenidas a través de fusión de protoplastos y aplicación de N-metil-N-nitro-N-Nitrosoguanidinio (NG) en cepas silvestres previamente caracterizadas y seleccionadas por su buena capacidad biocontroladora en Rhizoctonia solani. Se evaluó su efecto in vitro a través de antagonismo directo en cultivos duales, metabolitos volátiles y metabolitos difusibles en dos cepas de Rhizoctonia solani (509 (GA 2-1) y 618 (GA 4)). Las pruebas de antagonismo se realizaron a la temperatura y pH óptimo de crecimiento del patógeno. Las cepas ThF 2-1, ThF 2-18, ThF 3-3, ThF 4-15 y la cepa ThF 5-8, presentaron los mejores porcentajes de inhibición. También se evaluó la capacidad biocontroladora de las cepas antes indicadas, bajo condiciones de invernadero en plántulas de tomate de los cultivares 92.95 y Góndola susceptibles. En la prueba de inocuidad se evaluó altura, peso fresco y seco de las plántulas. Todas las cepas resultaron inocuas. Para evaluar la capacidad biocontroladora, las cepas se aplicaron en forma de pellets de alginato de sodio (1,7 g pellet/ L suelo) al suelo en macetas, previamente inoculado con el fitopatógeno en suelo estéril y se compararon con un tratamiento testigo (sólo Rhizoctonia solani) y con un tratamiento a base del fungicida pencycuron. Se evaluó peso fresco y seco de las plantas, cancrosis, desarrollo radical y mortalidad. La cepa mejorada ThF 4-15 fue el mejor agente de biocontrol en el cultivar de tomate Góndola, cuando se evaluó el nivel de cancrosis comparado con sus genotipos silvestres. En cuanto al desarrollo radical de las plantas los tratamientos que incluyeron a las cepas mejoradas, no tuvieron diferencias. También se estudió la viabilidad y sobrevivencia de las cepas bioantagonistas formulados como pellets en dos suelos (Antumapu y La Palma) a tres temperaturas de almacenaje (22ºC, 5ºC y temperatura ambiental de laboratorio (18,6-25°C)) determinándose su capacidad antagónica sobre el fitopatógeno a los 30, 60 y 90 días, observándose que las cepas biocontroladoras se mantuvieron viables en los suelos Antumapu y La Palma, al menos hasta los 90 días a las temperaturas estudiadas. Se determinó también que ellos conservan su capacidad antagónica
72

Efectos in vitro de mutantes de trichoderma spp. en el control de Rhizoctonia solani (Kühn) y Phytophthora nicotianae (Breda de Haan)

Arias Díaz, Mauricio Esteban January 2005 (has links)
No description available.
73

Control biológico de Rhizoctonia solani (Kühn) mediante 2 cepas mejoradas de Trichoderma harzianum (Rifai) en tomate (Lycopersicon esculentum Mill.)

Sánchez Téllez, Soledad Victoria January 2009 (has links)
Memoria para optar al título profesional de Ingeniera Agrónoma Mención Sanidad Vegetal / El control de Rhizoctonia solani y otros patógenos del suelo en el cultivo del tomate, se realiza fundamentalmente mediante fumigaciones con bromuro de metilo. En la búsqueda de alternativas de control amigables con el medio ambiente, se evaluó la efectividad de dos cepas mejoradas de Trichoderma harzianum sobre el biocontrol de Rhizoctonia solani en un cultivo comercial de tomates bajo invernadero. Las cepas utilizadas fueron: Th 12A 10.1, y Th F2-1, previamente seleccionadas como buenos biocontroladores del fitopatógeno. Ambas fueron aplicadas en forma de pellets de alginato de sodio (1,7 g / planta). Estas fueron comparadas con aplicaciones del biofungicida comercial Trichonativa (aplicado en dosis de 5 cc / L en pre-transplante y 1 L / Ha en post-transplante) y con una aplicación de bromuro de metilo (60 g / m2 , con 5 días de exposición). Los bioantagonistas fueron aplicados en 1 y 3 oportunidades. Se evaluó: rendimiento de frutos, peso fresco de plantas y nivel de daño causado por R. solani. Además se determinó la persistencia de la población y capacidad antagónica de los biantagonistas en estudio. En rendimiento total y de frutos de calibre primera, destacan los resultados de la cepa Th F2-1 aplicada en tres oportunidades en relación al tratamiento con una aplicación de la misma cepa mejorada. Mientras que no existieron diferencias significativas entre los tratamientos en el peso fresco de las plantas. En cuanto al nivel de daño, la cepa Th F2-1 aplicada en tres oportunidades se diferenció del tratamiento testigo, sin embargo, los bajos niveles de la enfermedad no permitieron una buena apreciación de las características antagónicas de las cepas restantes. Trichoderma spp. en los suelos inoculados, persistió durante 3 meses en los tratamientos con aplicaciones de las cepas mejoradas de T. harzianum en tres oportunidades, destacando la cepa Th F2-1. En relación a la mantención de la capacidad antagónica de las cepas, los aislados de los tratamientos con aplicaciones de las cepas Th F2-1 y Th 12A 10.1 mantuvieron su capacidad antagónica durante el ensayo, no así las cepas aisladas desde los tratamientos con el biofungicida comercial. / The diseases caused by soilborne pathogens in tomato, such as R. solani, are usually controlled by soil fumigation. The aim of this research was to study the effectivity of the biological control of R. solani utilizing two Trichoderma harzianum improved strains (Th 12A 10.1 and Th F2-1) compared with Methyl Bromide and a commercial formulation of Trichoderma spp. in cropped under greenhouse in Chile. Fruit yield, fresh weight of plants and the canker level caused by R. solani were evaluated. The viability of improved strains of T. harzianum and their antagonistic activity on Rhizoctonia solani in tomatoes were also evaluated. For fruit yield, there were not differences between the treatments and the control, except the treatment with methyl bromide, which presented lower yield. In the parameter fresh weight of plants were not detected differences between treatments. For canker level the best treatment was the Th F2-1 strain applied in three times. The population viability of T. harzianum was of 3 months in the treatments with 3 applications of the improved strains. The treatments with Th F2-1 and Th 12A 10.1 applications kept theirs antagonistic effects on R. solani during the present research. The strains isolated of the treatments with applications of the commercial product, does not kept their antagonistic effects on R. solani.
74

Developing a New Inoculation Method, and Evaluating the Potential Biological Control of Rhizoctonia solani by Penicillium pinophilum on Sugar Beet

Haque, Md Ehsanul January 2020 (has links)
Rhizoctonia solani causes damping-off, and root and crown rot of sugar beet (Beta vulgaris L.) and overwinters as sclerotia and mycelia. Research was conducted to determine how best to produce large quantities of sclerotia and mycelia in vitro, and compare their pathogenicity with traditionally used colonized barley grains to sugar beet in vitro and in vivo. The greatest number of sclerotia was produced on amended clarified V8 medium and sclerotia caused more disease compared to barley inoculum in the greenhouse. The bio-control potential of Penicillium pinophilum on R. solani AG2-2 on sugar beet was evaluated in vitro and in vivo. Results showed that the presence of P.pinophilum with R.solani reduced damping-off by 75% and thus have the potential to be developed as a bio-control agent for this pathogen.
75

A Histopathological Study of Rhizoctonia Solani Kuhn Infection of Resistant and Susceptible Lines of Lima Bean (Phaseolus Limensis Macf.)

Bunnag, Chulevan 01 May 1969 (has links)
The effects of Rhizoctonia solani on the hypocotyls of resistant and susceptible lines of lima bean were studied . The fungus attacks lima bean at one or more stages during host development and causes pre-and -postemergence damping-off, root rot, and foliage blight. The isolate of the fungus used in this study was obtained from infected radishes grown in Salt Lake County. Utah. The formation of infection cushions and modes of penetration by this fungus was no different on the resistant and susceptible lima bean hypocotyls . The infection process was studied under laboratory conditions . Differential staining showed that the fungal hyphae were closely appressed to the host surface , and at first along the longitudinal axis o f the epidermal cells. Later, hyphal branches grew in oblique and transverse directions . Aggregated hyphal tips formed infection cushions , which gave rise to one or more infection pegs that penetrated the host directly . Following penetration, both intercellular and intracellular hyphae were formed. The build-up of masses of hyphae occurred as club-shaped structures in the cortex of the susceptible lima bean hypocotyls , but were not observed in the resistant hypocotyls . The extents of infection in the resistant and susceptible lima bean hypocotyls were different at 7 days after inoculation. The hyphae in the susceptible hypocotyl had penetrated into vascular bundles and pith , whereas the hyphae had penetrated the cortex and pith of the resistant hypocotyl but were not observed in the vascular tissue. Stomatal penetration from individual hyphal side branches was rare and apparently of minor importance as a means of penetration by this isolate .
76

Development of a specific and reliable molecular marker to detect Stachybrotyrs [i.e. Stachybotrys] elegans, a destructive mycoparasite of Rhizoctonia solani

Wang, Xiben, 1973- January 2000 (has links)
No description available.
77

QUALIDADE FISIOLÓGICA E SANITÁRIA DE SEMENTES DE CEDRO E PATOGENICIDADE DE Rhizoctonia spp. / PHYSIOLOGICAL AND SANITARY QUALITY OF Cedrela fissilis SEEDS AND PATHOGENICITY OF Rhizoctonia spp.

Lazarotto, Marília 24 February 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The native forest specie Cedrela fissilis Vell. had its population reduced because of the extraction of its wood. The worry of its extinction has been favoring researches related with the specie perpetuation, including those which involve seeds quality. However, there is little knowledge about the pathogens which could contribute to the low germination or other problems in adult individuals. This research has the objective to evaluate the physiological and sanitary quality of C. fissilis seeds, from different places of the south of Brazil. The vigor was evaluated with different tests, the sanitary with two methods of detection and transmission of fungi by seeds, pathogenicity of fungi isolated from the seeds and seeds treatment. The vigor tests showed that the seeds from different places had different physiological potentials. Both of detection methods were efficient to identify the most of the fungi found in the seeds. Some of the fungi were identified on high incidences and in both tests: Penicillium sp., Pestalotia sp., Phomopsis sp. and Rhizoctonia sp. This last one and Fusarium sp. were transmitted by seeds. One of the Rhizoctonia sp. isolates was pathogenic, causing roots rotting, and damping-off. The seeds treatment with garlic extract (Allium sativum) and physical treatment (70°C for 48 hours) could be use to reduce the fungi incidence or to eliminate these, respectively. For the treatment of inoculated and noninoculated seeds with Rhizoctonia sp., the combination of biological (Thichoderma spp.) and chemic treatments was efficient to reduce the incidence of most of fungi, including that which was inoculated in the seeds. / O cedro (Cedrela fissilis) é uma espécie florestal nativa, cuja população foi reduzida em função da extração de sua madeira. A preocupação com sua extinção vêm favorecendo pesquisas relacionadas à perpetuação da espécie, dentre estas, aquelas envolvendo a qualidade de suas sementes. Porém, pouco se sabe sobre patógenos que podem estar contribuindo para a baixa germinação de sementes, ou para problemas futuros em indivíduos já estabelecidos. Diante disto, este trabalho tem como objetivo geral avaliar a qualidade fisiológica e sanitária de sementes de cedro, procedentes de diferentes localidades dos estados do sul do Brasil. Avaliou-se o vigor destas sementes, através de diferentes testes; a qualidade sanitária, por dois métodos de detecção e teste de transmissão; a patogenicidade de fungos isolados de sementes; e o efeito de diferentes tratamentos. Os testes de vigor demonstraram que as sementes possuíam diferentes potenciais fisiológicos, dependendo da procedência. Ambos os testes de detecção utilizados, foram eficientes para a maioria dos fungos associados às sementes de cedro. Alguns fungos ocorreram em altas incidências, em ambos os testes: Penicillium sp., Pestalotia sp., Phomopsis sp. e Rhizoctonia sp., sendo este e Fusarium sp., os únicos transmitidos via sementes. A patogenicidade, realizada com isolados de Rhizoctonia sp. identificou um isolado patogênico, provocando apodrecimento de raízes e colo, e posterior tombamento. Os tratamentos de sementes com extrato de alho (Allium sativum) e tratamento físico (estufa a 70°C por 48 horas) são promissores para a redução da incidência de fungos ou mesmo erradicação de alguns deles, respectivamente. Tratamentos com sementes inoculadas e não-inoculadas com Rhizoctonia sp. demonstraram que a combinação de produto biológico, à base de Trichoderma spp. (Agrotrich Plus®), mais um fungicida protetor (Captan) é eficiente para redução de patógenos, incluindo àquele inoculado nas sementes.
78

Diversidade genética de Rhizoctonia spp. e análise de sequência multilocos

Nakatani, Andréia Kazumi [UNESP] 05 May 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:34:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-05-05Bitstream added on 2014-06-13T20:25:38Z : No. of bitstreams: 1 nakatani_ak_dr_fca.pdf: 853202 bytes, checksum: df12fbbfd3cd127e44acff93e2b14eff (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Rhizoctonia solani Kuhn (teleomorfico: Thanatephorus cucumeris (Frank) Donk) e um fungo basidiomycota, fitopatogeno anamorfico com uma ampla gama de hospedeiros, incluindo mais de 500 generos de plantas. Causam doencas em varias culturas importantes no mundo, infectando sementes, raizes, folhas, hastes e frutos. A diversidade genetica de 274 isolados de Rhizoctonia spp. coletados, em diversas partes do mundo, foram caracterizados utilizando-se a analise de sequencia da regiao ITS1-5.8S rDNA-ITS2, para avaliar o grau de variabilidade genetica dentro e entre grupos de anastomose (AGs), incluindo os isolados padroes dos respectivos AGs. A arvore filogenetica gerada pela analise das sequencias da regiao ITS foi suportada por 66% gbootstrap h para a separacao em nove maiores grupos. De maneira geral, o agrupamento dos isolados de Rhizoctonia spp. ocorreu de acordo com os grupos de anastomose ja previamente determinados. A similaridade de sequencias entre isolados de mesmo hospedeiro, mas de diferente origem geografica foi elevada. Por exemplo, isolados de melao do Brasil e Espanha mostraram 97,2% de similaridade na regiao ITS1 e de 98,6 a 99,3 % na regiao ITS2. Isolados de batata do Brasil e da Espanha mostram similaridade de sequencia de 94%. Para melhorar a qualidade das sequencias da regiao ITS1-5.8S rDNA-ITS2 dos isolados CBS316.84 (Waitea circinata) e CBS569.83 (Ceratobasidium globisporum) foram gerados clones, e a analise das sequencias dos clones apresentaram variacao de 94,9 a 100 % de identidade 2 entre os clones do isolado CBS316.84 e de 91,9 ate 100 % para os clones do isolado CBS569.83. Os 44 isolados selecionados previamente, a partir do cladograma gerado da regiao ITS1-5.8S-ITS2 foram submetidos ao sequenciamento dos genes ATP sintase subunidade 6 mitocondrial (ATP6), fator de elongacao 1-alpha (EF-1 ¿), RNA polimerase 2 (RPB2) e a regiao ITS. As arvores filogeneticas baseadas na analise gneighbor-joining h geradas a partir das... / Rhizoctonia solani Kuhn (teleomorph: Thanatephorus cucumeris (Frank) Donk) is an anamorphic plant pathogenic basidiomycota fungus with a wide host range, including more than 500 genera of higher plants. Species cause disease in several important crops worldwide by infecting the seeds, roots, leaves, stems and fruits. Two hundred seventy four isolates from plant pathogenic fungus Rhizoctonia spp. collected worldwide was characterized using ITS1-5.8S rDNA-ITS2 sequence analysis to assess the degree of genetic variability within and among anastomosis groups (AGs), including tester isolates of the respective AGs. Within the ITS phylogenetic tree, there was support (66% bootstrap value) for the separation into nine major groups. In general the clustering isolates of Rhizoctonia species agreed with previously determined anastomosis groups. Nucleotide sequence similarity between isolates from the same host but from different geographic origin was high e.g. isolates from melon from Brazil and Spain showed from 97.2 % similarity in ITS1 region and 98.6 to 99.3 % in ITS2 region. Potato isolates from Brazil and Spain showed a sequence similarity about 94%. Several isolates from the same geographic origin were found closely related to different anastomosis groups such as isolates from potato, tomato, soybeans, beans, sugar beet and have been reported different symptoms around the world. Were generated cloning of ITS region from CBS 316.84 (Waitea circinata) and CBS 569.83 (Ceratobasidium globisporum) isolates to improve the sequence quality. The clones showed 94.9 to 100% and 91.9 to 100% identity respectively. Fourty four isolates were selected from the ITS1-5.8S rDNA-ITS2 phylogenetic tree for sequencing using the genes of ssembling the Fungal tree of Life (AFTOL) such as ATP 4 synthase subunit 6 mitocondrial (ATP6), elongation factor 1-alpha (EF-1 ¿) and RNA polymerase 2 (RPB2). The phylogenetic tree generated by sequences of EF-1 ¿ and RPB2 in general.
79

Extratos de resíduos agroindustriais para o controle de fungos fitopatogênicos / Agroindustrial by-products extracts to control phytopathogenic fungi

Heloisa Malaguetta 26 February 2016 (has links)
O Brasil tem uma posição de destaque mundial na produção de frutas e alguns grãos, os quais são comercializados in natura ou na forma de produtos processados. O processamento têm várias vantagens, porém gera grandes quantidades de resíduos, os quais têm sido aproveitados para a alimentação animal e geração de energia. Entretanto, muito tem sido relatado sobre o potencial bioativo desses materiais, dentre eles a ação fungitóxica de alguns de seus compostos sobre fungos fitopatogênicos. Assim, o objetivo desse trabalho foi avaliar o potencial de extratos de resíduos agroindustriais de abacate, uva, café, manga, abacaxi, maracujá e caju na inibição do crescimento micelial in vitro dos fungos Fusarium pallidoroseum, Colletotrichum dematium, Rhizoctonia solani e Phomopsis sp., bem como a composição química do resíduo mais promissor. Os resíduos foram liofilizados, moídos e submetidos a extração com etanol 80% (etanol:água; 8:2, v/v) em banho de ultrassom (extrato denominado bruto ou EB). O EB também foi tratado com a resina Amberlite XAD-2, visando à eliminação de açúcares e interferentes, dando assim origem ao extrato semi-purificado (EP). Os extratos que apresentaram alto rendimento foram avaliados quanto à atividade antifúngica in vitro e teor de compostos fenólicos totais. A amostra que apresentou os melhores índices de inibição foi selecionada para dar continuidade ao estudo, sendo a mesma fracionada em coluna de gel Sephadex LH-20. Os extratos e as frações ativas, detectadas pelo ensaio de bioautografia, foram analisadas quanto a composição química pelas técnicas de HPLC e GC/MS. Na análise de fenólicos totais os maiores teores encontrados foram para a casca de abacate, enquanto que para o ensaio de inibição de crescimento micelial in vitro o melhor resultado foi para a semente de abacate, tanto para o EB quanto para o EP. Desta maneira, a semente de abacate foi selecionada para as etapas posteriores. Para o fracionamento em gel Sephadex LH-20 foi eleito o EP para F. pallidoroseum enquanto que para os demais fungos foi eleito o EB. No fracionamento do EP obtiveram-se 13 frações, sendo que as frações 3 e 4 foram ativas, enquanto que no do EB obtiveram-se nove, sendo as frações 3, 4 e 5 ativas. Pela técnica de HPLC foram detectados em comum nas frações 3, 4 e 5 do EB dois compostos majoritários, e nas frações 3 e 4 do EP, sete compostos, os quais não puderam ser identificados pelos padrões comerciais disponíveis. Já pela técnica de GC/MS foi possível a identificação de quatro compostos em comum nas frações ativas do EB e de 11 nas frações do EP. Dentre os compostos presentes nas frações ativas, foram identificados ácidos graxos, os quais têm sido reconhecidos por apresentarem ação antifúngica. Assim, pode-se concluir que os resíduos agroindustriais estudados são fontes de compostos com atividade antifúngica, podendo assim ser uma alternativa para o controle de fungos fitopatogênicos à cultura da soja / Brazil holds an important position in the world production of fruit and some grains, which are commercialized in natura or in processed products. The processing has several advantages, but generates large amounts of by-products which have been used for animal feed and power generation. However, bioactive potential of these materials have been reported, including the fungitoxic effect. The goal of this study was to evaluate the potential of agro-industrial by-products extracts of avocado, grape, coffee, mango, pineapple, passion fruit and cashew to inhibit in vitro mycelial growth of fungi Fusarium pallidoroseum, Colletotrichum dematium, Rhizoctonia solani and Phomopsis sp. as well as the chemical composition of the most promising by-products. The by-products were freeze-dried, milled and the extraction was done with ethanol 80% (ethanol:water, 8:2, v/v) in an ultrasound bath (called crude extract or CE). The CE was also treated with Amberlite XAD-2 to eliminate sugars and interfering compounds so that the semi-purified extract (PE) could be obtained. Extracts with high yield were evaluated to in vitro antifungal activity and phenolic compounds content. Samples with the best inhibition rates were selected to continue this study, and it was fractioned on gel Sephadex LH-20. The extracts and the active fractions, detected by bioautography, were analyzed by HPLC and GC/MS. The highest phenolic content was found in the avocado peel, meanwhile for the mycelial growth inhibition in vitro, the best result was found in the avocado seeds for both extracts (CE and PE). Thus, avocado seed was selected for subsequent steps. For fractionation on Sephadex LH-20 gel, PE was chosen for F. pallidoroseum and CE for the other fungi. For PE, 13 fractions were obtained in which fractions 3 and 4 were active. For CE, 9 fractions were obtained and the actives were 3, 4 and 5. In CE, HPLC technique detected two major compounds in common in fractions 3, 4 and 5. In PE, seven major compounds were detected in fractions 3 and 4, which could not be identified by commercial available standards. By the GC/MS technique was possible to identify four compounds in common in the active CE fractions and 11 in PE. Among the compounds presented in the active fractions, fatty acids were identified. It has been reported that antifungal action has been found in these compounds. Therefore, the studied agroindustrial by-products are sources of compounds with antifungal activity and they can be used as an alternative to control phytopathogenic fungi on soybean
80

Extratos de resíduos agroindustriais para o controle de fungos fitopatogênicos / Agroindustrial by-products extracts to control phytopathogenic fungi

Malaguetta, Heloisa 26 February 2016 (has links)
O Brasil tem uma posição de destaque mundial na produção de frutas e alguns grãos, os quais são comercializados in natura ou na forma de produtos processados. O processamento têm várias vantagens, porém gera grandes quantidades de resíduos, os quais têm sido aproveitados para a alimentação animal e geração de energia. Entretanto, muito tem sido relatado sobre o potencial bioativo desses materiais, dentre eles a ação fungitóxica de alguns de seus compostos sobre fungos fitopatogênicos. Assim, o objetivo desse trabalho foi avaliar o potencial de extratos de resíduos agroindustriais de abacate, uva, café, manga, abacaxi, maracujá e caju na inibição do crescimento micelial in vitro dos fungos Fusarium pallidoroseum, Colletotrichum dematium, Rhizoctonia solani e Phomopsis sp., bem como a composição química do resíduo mais promissor. Os resíduos foram liofilizados, moídos e submetidos a extração com etanol 80% (etanol:água; 8:2, v/v) em banho de ultrassom (extrato denominado bruto ou EB). O EB também foi tratado com a resina Amberlite XAD-2, visando à eliminação de açúcares e interferentes, dando assim origem ao extrato semi-purificado (EP). Os extratos que apresentaram alto rendimento foram avaliados quanto à atividade antifúngica in vitro e teor de compostos fenólicos totais. A amostra que apresentou os melhores índices de inibição foi selecionada para dar continuidade ao estudo, sendo a mesma fracionada em coluna de gel Sephadex LH-20. Os extratos e as frações ativas, detectadas pelo ensaio de bioautografia, foram analisadas quanto a composição química pelas técnicas de HPLC e GC/MS. Na análise de fenólicos totais os maiores teores encontrados foram para a casca de abacate, enquanto que para o ensaio de inibição de crescimento micelial in vitro o melhor resultado foi para a semente de abacate, tanto para o EB quanto para o EP. Desta maneira, a semente de abacate foi selecionada para as etapas posteriores. Para o fracionamento em gel Sephadex LH-20 foi eleito o EP para F. pallidoroseum enquanto que para os demais fungos foi eleito o EB. No fracionamento do EP obtiveram-se 13 frações, sendo que as frações 3 e 4 foram ativas, enquanto que no do EB obtiveram-se nove, sendo as frações 3, 4 e 5 ativas. Pela técnica de HPLC foram detectados em comum nas frações 3, 4 e 5 do EB dois compostos majoritários, e nas frações 3 e 4 do EP, sete compostos, os quais não puderam ser identificados pelos padrões comerciais disponíveis. Já pela técnica de GC/MS foi possível a identificação de quatro compostos em comum nas frações ativas do EB e de 11 nas frações do EP. Dentre os compostos presentes nas frações ativas, foram identificados ácidos graxos, os quais têm sido reconhecidos por apresentarem ação antifúngica. Assim, pode-se concluir que os resíduos agroindustriais estudados são fontes de compostos com atividade antifúngica, podendo assim ser uma alternativa para o controle de fungos fitopatogênicos à cultura da soja / Brazil holds an important position in the world production of fruit and some grains, which are commercialized in natura or in processed products. The processing has several advantages, but generates large amounts of by-products which have been used for animal feed and power generation. However, bioactive potential of these materials have been reported, including the fungitoxic effect. The goal of this study was to evaluate the potential of agro-industrial by-products extracts of avocado, grape, coffee, mango, pineapple, passion fruit and cashew to inhibit in vitro mycelial growth of fungi Fusarium pallidoroseum, Colletotrichum dematium, Rhizoctonia solani and Phomopsis sp. as well as the chemical composition of the most promising by-products. The by-products were freeze-dried, milled and the extraction was done with ethanol 80% (ethanol:water, 8:2, v/v) in an ultrasound bath (called crude extract or CE). The CE was also treated with Amberlite XAD-2 to eliminate sugars and interfering compounds so that the semi-purified extract (PE) could be obtained. Extracts with high yield were evaluated to in vitro antifungal activity and phenolic compounds content. Samples with the best inhibition rates were selected to continue this study, and it was fractioned on gel Sephadex LH-20. The extracts and the active fractions, detected by bioautography, were analyzed by HPLC and GC/MS. The highest phenolic content was found in the avocado peel, meanwhile for the mycelial growth inhibition in vitro, the best result was found in the avocado seeds for both extracts (CE and PE). Thus, avocado seed was selected for subsequent steps. For fractionation on Sephadex LH-20 gel, PE was chosen for F. pallidoroseum and CE for the other fungi. For PE, 13 fractions were obtained in which fractions 3 and 4 were active. For CE, 9 fractions were obtained and the actives were 3, 4 and 5. In CE, HPLC technique detected two major compounds in common in fractions 3, 4 and 5. In PE, seven major compounds were detected in fractions 3 and 4, which could not be identified by commercial available standards. By the GC/MS technique was possible to identify four compounds in common in the active CE fractions and 11 in PE. Among the compounds presented in the active fractions, fatty acids were identified. It has been reported that antifungal action has been found in these compounds. Therefore, the studied agroindustrial by-products are sources of compounds with antifungal activity and they can be used as an alternative to control phytopathogenic fungi on soybean

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