scholarly journals Efecto in vitro de controladores biológicos sobre Colletotrichum spp. y Botrytis spp.

2017 ◽  
Vol 1 (2) ◽  
pp. 25
Author(s):  
Malluri Goñas Goñas ◽  
Leidy Gheraldinne Bobadilla Rivera ◽  
Jesús Rascón ◽  
Nora Y. Vera Obando

<p>La presente investigación, realizada en el Laboratorio de Investigación de Entomología y Fitopatología de la Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas, tuvo el objetivo de evaluar el efecto in vitro de cuatro controladores biológicos (Trichoderma harzianum, T. viride, T. asperellum y Clonostachys rosea) frente a los hongos patógenos Colletotrichum spp. y Botrytis spp. Se utilizó la metodología de cultivos duales, que consiste en enfrentar el enemigo biológico en un extremo de una placa Petri y el hongo patógeno en el otro. Se establecieron seis tratamientos que incluyeron un testigo absoluto y un testigo químico (propineb 1000 ppm) por patógeno, con cinco repeticiones por tratamiento. Se logró el aislamiento de los fitopatógenos Colletotrichum spp., agente causal de la antracnosis del mango, y Botrytis spp., agente causal de la rancha en azucenas. Al comparar el crecimiento radial cada 24 horas, se encontró que 96 horas después del enfrentamiento, las cepas de Trichoderma inhibieron el crecimiento radial de los patógenos, diferenciándose significativamente del testigo absoluto. Al evaluar el porcentaje de inhibición del crecimiento radial (PICR) en Botrytis spp., las cepas de Trichoderma spp. presentaron mayor PICR, sin embargo, no presentaron diferencias significativas con el testigo químico. En Colletotricum spp., las cepas de Trichoderma spp. presentaron mayor PICR, y además diferencias significativas estadísticas con el testigo químico. Finalmente, cabe destacar que la cepa de C. rosea no inhibió el crecimiento radial de los patógenos, mostrando los PICR más bajos.</p>

2021 ◽  
Author(s):  
◽  
Román Müller

En nuestro país como a nivel mundial, el tomate (Solanum lycopersicum L. = Lycopersicun esculetum Mill.), es una de las hortalizas más consumida y de mayor valor económico. Durante su cultivo, se encuentra expuesto a distintas plagas, entre ellas a Sclerotium rolfsii. Para un control eficiente de las enfermedades es conveniente utilizar un manejo integrado de plagas, utilizando distintas técnicas de cultivo tanto clásicas como nuevas tecnologías como el control biológico, que contemplen paralelamente el cuidado del medio ambiente y la producción del cultivo. Trichoderma spp., es uno de los organismos más utilizados para el control biológico de las enfermedades de origen fúngico. El objetivo de este trabajo fue evaluar la eficacia de la cepa de Trichoderma harzianum del IFSC como controlador biológico de Sclerotium rolfsii, ya sea sola o con fungicidas comerciales y analizar su capacidad como promotora de crecimiento del cultivo de tomate platense variedad Luna. Se evaluó el comportamiento de Th del IFSC para controlar a Sclerotium rolfsii in vitro, en cámara de crecimiento y a campo. Como resultado de los ensayos se comprobó que la cepa de Th del IFSC incrementó la germinación en condiciones in vitro e inhibió el desarrollo de S. rolfsii, poniéndose en evidencia el mecanismo de destrucción de los esclerocios. Indujo la promoción del crecimiento de la plántula obteniéndose plantas con mayor sanidad y porte. La cepa Th del IFSC tuvo mayor afinidad con el fungicida Captan incrementando la germinación y el desarrollo de las plántulas en el cultivo de tomate. Se comprobó la factibilidad del uso de Th del IFSC en un planteo de manejo integrado en el cultivo de tomate platense variedad Luna ya sea sola o con un fungicida como Captan.


2012 ◽  
Vol 102 (11) ◽  
pp. 1054-1063 ◽  
Author(s):  
Chi-Hua Cheng ◽  
Chia-Ann Yang ◽  
Kou-Cheng Peng

Previous studies have shown that the extracellular proteins of Trichoderma harzianum ETS 323 grown in the presence of deactivated Botrytis cinerea in culture include a putative l-amino acid oxidase and have suggested the involvement of this enzyme in the antagonistic mechanism. Here, we hypothesized that the mycoparasitic process of Trichoderma spp. against B. cinerea involves two steps; that is, an initial hyphal coiling stage and a subsequent hyphal coiling stage, with different coiling rates. The two-step antagonism of T. harzianum ETS 323 against B. cinerea during the mycoparasitic process in culture was evaluated using a biexponential equation. In addition, an l-amino acid oxidase (Th-l-AAO) was identified from T. harzianum ETS 323. The secretion of Th-l-AAO was increased when T. harzianum ETS 323 was grown with deactivated hyphae of B. cinerea. Moreover, in vitro assays indicated that Th-l-AAO effectively inhibited B. cinerea hyphal growth, caused cytosolic vacuolization in the hyphae, and led to hyphal lysis. Th-l-AAO also showed disease control against the development of B. cinerea on postharvest apple fruit and tobacco leaves. Furthermore, an apoptosis-like response, including the generation of reactive oxygen species, was observed in B. cinerea after treatment with Th-l-AAO, suggesting that Th-l-AAO triggers programmed cell death in B. cinerea. This may be associated with the two-step antagonism of T. harzianum ETS 323 against B. cinerea.


Author(s):  
P Rajeswari ◽  
R Kapoor

Fusarium oxysporum, the soil borne pathogen causes vascular wilt, on majority of crop plants. It has been demonstrated that two different species of Trichoderma and Pseudomonas fluorescens suppress disease by different mechanisms. Therefore, application of a mixture of these biocontrol agents, and thus of several suppressive mechanisms, may represent a viable control strategy. A necessity for biocontrol by combinations of biocontrol agents can be the compatibility of the co-inoculated micro-organisms. Hence, compatibility between Trichoderma spp. and Pseudomonas fluorescens that have the ability to suppress Fusarium oxysporum in vitro on the activity of pectinolytic enzymes of Fusarium oxysporum. The activity of pectinolytic enzymes, i.e. pectin methyl esterase, endo and exo polymethylgalacturonases and exo and endo pectin trans eliminases produced by Fusarium oxysporum (Control) was higher. Maximum inhibition of pectin methylesterase, exo and endo polymethylgalacturonase and exo and endopectin trans eliminase was shown by culture filtrate of Trichoderma viride + Pseudomonas fluorescens (Tv+Pf) (1+2%), followed by Trichoderma harzianum + Pseudomonas fluorescens, (Th +Pf) (1.5+2%) and Trichoderma viride + Trichoderma harzianum (Tv+Th) (1+1.5%). However, pathogenecity suppression of Fusarium oxysporum, a causative of Arachis hypogaea. L by the compatible combination of Trichodema viride + Pseudomonas fluorescens (1+2%) was significantly better as compared to the single bio-agent. This indicates that specific interactions between biocontrol agents influence suppression of pathogenicity factors directly by combinations of these compatible bio-agents.Int. J. Agril. Res. Innov. & Tech. 7 (2): 36-42, December, 2017


Author(s):  
Wilson Ceiro-Catasú ◽  
Yusel Vega-González ◽  
María Taco-Sánchez ◽  
Ramiro Gaibor-Fernández ◽  
Oandis Sosa-Sánchez

Tobacco production is a key line in the Cuban economy and generates the largest income in the agricultural sector. Within phytopathogens affecting this plant, Fusarium spp., constitutes a pest of interest, due to vascular involvements that cause deterioration of the commercial value of the leaf. Therefore, the research was carried out with the aim of determining the antagonistic activity in vitro of native strains of Trichoderma harzianum and T. viride on isolates of Fusarium oxysporum and F. phyllophylum, from Nicotiana tabacum L. in Granma province, Cuba. The work was carried out at the Laboratory of Agricultural Microbiology, University of Granma. Half dextrose potato agar was prepared to establish the dual crops of Trichoderma spp. vs. Fusarium spp. Once the treatments were established and the incubation time had elapsed, the percentage inhibition of mycelial growth, antagonistic capacity and mycoparasitic activity was determined. A fully randomized design with four replicas per treatment was used and a two factorial ANOVA and Tukey test (p≤0.05) were used for statistical processing. It was shown that the strains of Trichoderma spp., recorded intermediate values of phytopathogenic inhibition, the competitiveness of the antagonist was mostly located in class two of the Bell scale and it was found that penetration, winding, vacuolization, deformation and granulation constitute the main forms of mycoparasitism. Which points to this biocontrol method as an alternative to consider for the management of Fusarium spp., in tobacco agroecosystems.


Bragantia ◽  
2008 ◽  
Vol 67 (1) ◽  
pp. 169-178 ◽  
Author(s):  
Enrique Torres ◽  
José Iannacone ◽  
Hilda Gomez

El moho foliar Cladosporium fulvum (Cooke 1883) produce una enfermedad que ataca el cultivo de tomate en invernadero en el Perú. Como alternativa al control de este patógeno se probó la eficiencia bajo condiciones in vitro e invernadero de cuatro hongos antagonistas: Hansfordia pulvinata (Berk y Curt 1958), Trichoderma harzianum (Rifai 1969), T. viride (Persoon 1821) y T. virens (Miller, Giddens y Foster 1963). El cultivo y crecimiento de los hongos se realizó en Agar Sabouraud para Trichoderma spp. y en Agar Jugo V8 para H. pulvinata. El bioensayo empleado fue el de placas precolonizadas propuesto por Krauss. En condiciones in vitro se observó que a 24 ºC y 72 h, el crecimiento de T. harzianum fue estadísticamente diferente de las otras tres especies ensayadas, y a 28 ºC fue similar a T. viride. A 24 ºC y a las 120 h, T. virens fue diferente de todas las especies evaluadas. A las 168 h el crecimiento de las tres especies de Trichoderma fue estadísticamente similar, diferenciándose de H. pulvinata. A 28 ºC a las 120 h y 168 h los resultados fueron estadísticamente similares para las tres especies de Trichoderma, pero diferentes de H. pulvinata. El mecanismo de acción más común para los hongos antagonistas fue el micoparasitismo. Finalmente, T. harzianum fue más eficiente debido a que redujo la severidad de la enfermedad en un 19,35 % bajo condiciones de invernadero.


2021 ◽  
Author(s):  
Kamila Lourrane Carvalho Alencar Rocha ◽  
Kárita Cristine Rodrigues Dos Santos ◽  
Maraiza Castro Bezerra ◽  
Vanice Conceição Do Nascimento

Introdução: O fitopatógeno Sclerotinia sclerotiorum, causador da doença conhecida popularmente como mofo-branco, acomete diversas culturas agrícolas em todo o mundo, sendo a soja uma das principais monoculturas mais afetadas. Seu alto grau de patogenicidade está associado à sua capacidade de formar escleródios que atuam como mecanismo de resistência e sobrevivência, podendo permanecer viáveis no solo por mais de dez anos e, em muitos casos, são resistentes aos agroquímicos. Considerando a necessidade de métodos biotecnológicos que contribuam no desenvolvimento agrícola sem promover danos ao ambiente e a população, os agentes de controle biológico (ACBs) são hoje vistos como um excelente artifício. Fungos do gênero Trichoderma podem ser considerados ACBs sagazes por apresentar inúmeros mecanismos com alto potencial antagônico a diversos fitopatógenos, que prejudicam a germinação de esporos, o crescimento das hifas e o desenvolvimento de escleródios. Objetivo: Avaliar o potencial antagônico de isolados de Trichoderma em inibir o crescimento micelial do fitopatógeno S. sclerotiorum através da liberação de metabólitos voláteis. Material e Métodos: Para análise da produção de metabólitos voláteis, os isolados Trichoderma harzianum ALL-42 e o Trichoderma asperellum TR-356 e o fitopatógeno S. sclerotiorum, foram dispostos em fundos de placas de Petri com meio Batata Dextrose Ágar (BDA), em face opostas ao outro, onde, no inferior estava o isolado de Trichoderma e no superior o fitopatógeno. Uma placa controle contendo apenas o fitopatógeno foi feita para comparação dos resultados. Resultados: Ambos isolados de Trichoderma apresentaram resultados positivos na inibição do crescimento micelial de S. sclerotiorum. Conclusão: A produção de metabólitos voláteis é uma ação secundária do gênero Trichoderma, ou seja, sua sobrevivência não depende desse mecanismo, ainda assim, esses metabólitos agem contra os antagonistas presentes no meio. Com isso, podemos verificar o quão eficiente é esse gênero como agente de controle biológico, entretanto, outros isolados precisam ser testados no intuito de encontrarmos agentes mais especialistas na defesa contra o fitopatógeno S. sclerotiorum, e dessa forma instigar os benefícios do emprego de agentes biotecnológicos no campo, visando a redução da aplicação de produtos químicos na agricultura.


2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Maria Lucia Garcia Simoes ◽  
Samia Maria Tauk-Tornisielo ◽  
Givaldo Rocha Niella ◽  
Daniel Mario Tapia Tapia

Trichoderma species , isolated from different producer regions of cocoa (Bahia, Brazil), were evaluated as for their capacity of usage in the biocontrol of the basidiomycete Moniliophthora perniciosa subgroup 1441, which causes the witches’ broom in cocoa. The isolates of Trichoderma were evaluated through individual indices so called %AP (Antagonistic Potential to Moniliophthora perniciosa subgroup 1441), %PG (Potential Growth in vitro) and %PSPr (Potential of Spore Production on rice) These indices were evaluated together, also they were used for the determination of Biological Control Potential (%BCP) of each antagonistic specie to the evaluated pathogen. Afterwards, the ability of the antagonistic to colonize and to produce spores on sterilized dry brooms was also evaluated. Some of the isolates Trichoderma spp showed a high %AP to the pathogen and high %PG, but did not present a significant %PSPr, turning impossible the spore production for biocontrol at commercial level. Significant differences were found within the individual indices among the species and isolates of the same species of Trichoderma spp, pointing out a great genetic variability among them. Trichoderma harzianum 911 showed to have the best biocontrol potential to the pathogen when compared to the other isolates, presenting a %BCP de 91.86% (mainly by the high %AP of 97,76%) a %PSPr of 99.53%, also producing 22.67 spores x 109. mL-1 by dry broom segment. Trichoderma harzianum 911 showed to be as promising isolate for future researches on biocontrol of cocoa witches’ broom.


2010 ◽  
Vol 36 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Marinês Pereira Bomfim ◽  
Abel Rebouças São José ◽  
Tiyoko Nair Hojo Rebouças ◽  
Saulo Sousa de Almeida ◽  
Ivan Vilas Boas Souza ◽  
...  

Para estudar a potencialidade antagônica de espécies de Trichoderma spp. in vitro e in vivo a Rhizopus stolonifer, patógeno causador da podridão floral do maracujazeiro, foram estudadas as espécies de Trichoderma viride, T. virens, T. harzianum e T. stromaticum. O crescimento micelial do fitopatógeno foi realizado pelo teste do pareamento de culturas, para crescimento individual foram utilizadas cinco temperaturas. Avaliou-se também o crescimento micelial em 24h e 48h, avaliando a taxa de crescimento dos isolados. Na produção de metabolitos voláteis e não voláteis foram utilizados papel celofane e sobreposição de placas. Em condição de campo os frutos/planta foram tratados com a suspensão na concentração de 2 x 10(8) Conídios/mL sendo avaliado o número médio de frutos aos 15 e 30. No pareamento de cultura todos os isolados de Trichoderma spp. apresentaram crescimento micelial, impedindo o desenvolvimento do fitopatógeno, para todos os isolados as temperaturas ideais de crescimento foram de 25ºC e 30ºC. Nos períodos de incubação de 24 e 48h, foram constatadas diferenças significativas no crescimento micelial entre os isolados os antagonistas apresentaram velocidade de crescimento maior que o fitopatógeno. Houve uma produção de metabólitos voláteis e não voláteis de ação antifúngica ao R. stolonifer. No ensaio em campo houve diferença significativa entre os tratamentos, verificando-se que o melhor resultado entre os antagonistas em estudo cujos percentuais de pegamento foram 74% para os tratamentos Trichoderma harzianum e T. virens, e os tratamentos T. viride e T. stromaticum obtiveram um porcentual de 75% enquanto a testemunha obteve um percentual de 42%.


2010 ◽  
Vol 46 (No. 2) ◽  
pp. 66-71 ◽  
Author(s):  
M. Ondřej ◽  
B. Cagaš ◽  
E. Ondráčková

Twenty fungal species were isolated from sclerotia of ergot (Claviceps purpurea) originating from rye. In in vitro tests with the anamorphic stage of ergot (known as Sphacelia segetum) high mycoparasitic activity was exhibited only by two of them &ndash; Clonostachys rosea and Trichoderma harzianum, moderate mycoparasitic activity was detected in Ulocladium sp., Clonostachys catenulata, Trichoderma hamatum, and Trichothecium roseum. In in vitro tests of mycoparasitic activity with sclerotia of the fungus Sclerotinia sclerotiorum their rapid and total destruction was brought about only by the fungi Clonostachys rosea and Trichoderma harzianum. The viability of overwintering ergot sclerotia in the soil was influenced by their placement, age, depth of placement and treatment with a conidial suspension of the fungus Clonostachys rosea. The highest viability values were reported in fresh one-year-old sclerotia. In two-year-old sclerotia their viability was reduced and their sensitivity to microbial activity was higher. The sclerotia aged 3 years or more did not germinate and were all microbiologically degraded in the soil. More than 80% of degradation of sclerotia which were 1 to 2 years old was caused by the fungus Clonostachys rosea. The degradation of sclerotia aged 3 to 4 years was brought about by bacteria, soil edafauna (mites, nematodes) and fungi of the genera Trichoderma, Fusarium, Clonostachys, etc.


2013 ◽  
Vol 32 (2) ◽  
pp. 83
Author(s):  
Budi Setyawan ◽  
Soekirman Pawirosoemardjo ◽  
Hananto Hadi

Penyakit jamur akar putih yang disebabkan oleh jamur Rigidoporus microporus merupakan salah satu penyakit penting pada tanaman karet di Indonesia, baik di perkebunan besar maupun rakyat. Kerugian secara finansial akibat penyakit ini sangat tinggi terutama di perkebunan karet rakyat. Pengendalian yang disarankan untuk penyakit ini adalah dengan pengendalian terpadu yaitu integrasi beberapa teknik pengendalian seperti pembongkaran tunggul, tanaman penutup tanah kacangan, seleksi bahan tanam, tanaman antagonis, biofungisida serta fungisida kimia yang diaplikasikan secara bijak. Hasil pengendalian pada umumnya masih belum memuaskan karena beberapa kendala teknis maupun non-teknis. Salah satu kendala yang cukup mengganggu yaitu mahalnya biaya, terutama bagi pekebun karet rakyat. Sebagai salah satu unsur dalam pengendalian terpadu, pengendalian secara biologi merupakan metode yang berpotensi besar. Pengendalian biologi menggunakan Trichoderma sp. sudah digunakan secara luas dan terbukti efektivitasnya. Cara tersebut tidak hanya efektif sebagai upaya preventif, tetapi juga murah, mudah diaplikasikan, dan ramah terhadap lingkungan. Triko Combi merupakan biofungisida semi-komersial yang diformulasi Balai Penelitian Getas dan memiliki empat jenis bahan aktif, yaitu Trichoderma viride, Trichoderma koningii, Trichoderma harzianum dan satu strain lokal Trichoderma sp. Pada percobaan dengan infeksi buatan Rigidoporus microporus di pembibitan polibeg menunjukkan adanya penekanan intensitas penyakit oleh perlakuan kombinasi empat jenis Trichoderma spp. tersebut dibandingkan bibit tanpa perlakuan, maupun bibit dengan aplikasi fungisida kimia. Hasil yang signifikan juga diperoleh melalui pengujian penghambatan langsung miselium Rigidoporus microporus secara in-vitro di laboratorium.


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