scholarly journals Efeito do lodo de esgoto na indução de supressividade in vitro a Phytophthora nicotianae

2003 ◽  
Vol 28 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Carolina Leoni ◽  
Raquel Ghini
Keyword(s):  
Triticum Aestivum ◽  
Medicago Sativa ◽  
Phytophthora Nicotianae ◽  
Phytophthora Spp ◽  
Trichoderma Sp ◽  
Aspergillus Sp

Uma alternativa de manejo das doenças causadas por Phytophthora spp. é o uso de matéria orgânica. No presente trabalho foi avaliada a potencialidade do lodo de esgoto na indução de supressividade in vitro a P. nicotianae. O efeito do lodo de esgoto incorporado ao solo na sobrevivência de P. nicotianae foi avaliado mediante um experimento fatorial com dois fatores: doses de lodo de esgoto (0, 10, 20 e 40% p/p) e concentrações de inóculo [0, 10 ou 20 g de grãos de trigo (Triticum aestivum) colonizados kg-1]. Aos 21 dias, quando aumentaram as doses de lodo de esgoto, a sobrevivência de P. nicotianae e os pHs das misturas diminuíram, e as condutividades elétricas (CE) aumentaram. As correlações entre a CE e a sobrevivência do patógeno foram negativas e significativas (P>0,05). Para estudar o efeito dos compostos químicos envolvidos na supressividade, foram obtidos extratos em água, H2SO4 2N e KOH 0,4N de misturas de areia – lodo de esgoto (20% p/p), e foram acrescentados ao meio de cultura e seu efeito avaliado no crescimento das colônias de P. nicotianae. O extrato ácido (H2SO4 2N) do tratamento com 20% de lodo de esgoto inibiu significativamente (P>0,05) o crescimento da colônia do patógeno. O efeito biológico foi estudado mediante isolamento de microrganismos em meio de cultura e seleção por antagonismo. No bioensaio com plântulas de alfafa (Medicago sativa) destacaram-se os isolados F9.1 (Aspergillus sp.) e A12.1 (actinomiceto, não identificado); e no teste de culturas pareadas destacou-se um Trichoderma sp. e dois actinomicetos por antibiose, e um Trichoderma sp. e três Aspergillus sp. por hiperparasitismo.

scholarly journals Actividad antifúngica de propóleos obtenidos en tres provincias de Cuba sobre hongos contaminantes en cultivo de tejidos vegetales

2014 ◽  
Vol 23 (6) ◽  
pp. 3-9
Author(s):  
René Dionisio Cupull-Santana ◽  
Remigio Cortés-Rodríguez ◽  
Ervelio Eliseo Olazábal-Manso ◽  
Carlos Alberto Hernández Medina
Keyword(s):  
Apis Mellifera ◽  
Penicillium Sp ◽  
Trichoderma Sp ◽  
Fusarium Sp ◽  
Aspergillus Sp

La investigación se realizó con el objetivo de evaluar las características fisicoquímicas y la actividad antifúngica de propóleos de Apis mellifera, provenientes de las provincias de Villa Clara, Cienfuegos y Sancti Spíritus, Cuba. Se utilizó el método de recolección por raspado y se estableció el contenido de cera, ceniza, material insoluble y resina de los propóleos crudos. Además, se evaluó la actividad antimicrobiana in vitro frente a los hongos Aspergillus sp., Penicillium sp., Fusarium sp., Trichoderma sp., Colletotrichum sp. y Monilia sp.; los extractos presentaron alta actividad antifúngica en un amplio rango de concentraciones; además, los parámetros fisicoquímicos presentaron valores semejantes y dentro de los establecidos por regulaciones internacionales.

scholarly journals SELEÇÃO IN VITRO DE FUNGOS ENDOFÍTICOS PARA O CONTROLE BIOLÓGICO DE Botrytis cinerea EM Eucalyptus benthamii

FLORESTA ◽  
2013 ◽  
Vol 43 (1) ◽  
pp. 145 ◽  
Author(s):  
José Antonio Sbravatti Junior ◽  
Celso Garcia Auer ◽  
Ida Chapaval Pimentel ◽  
Álvaro Figueredo dos Santos ◽  
Bruno Schultz
Keyword(s):  
Biological Control ◽  
Botrytis Cinerea ◽  
Fungal Endophytes ◽  
Gray Mold ◽  
Penicillium Sp ◽  
Trichoderma Sp ◽  
Forest Nurseries ◽  
Aspergillus Sp ◽  
Foliar Pathogens

   O Eucalyptus benthamii é uma das principais espécies de eucalipto plantadas na região Sul do Brasil, por sua resistência a geadas e por seu uso na produção florestal de madeira para fins energéticos. Na produção de mudas, uma das principais doenças ocorrentes em viveiros é o mofo-cinzento, causado pelo fungo Botrytis cinerea. Uma das alternativas para o controle dessa doença é o controle biológico com fungos endofíticos, os quais podem competir com os patógenos foliares de mudas de eucalipto. O objetivo deste trabalho foi isolar os fungos endofíticos provenientes de mudas de E. benthamii, identificá-los e selecioná-los para o controle de B. cinerea. Eles foram isolados do interior de tecidos vegetais desinfectados, identificados de acordo com critérios macro e micromorfológicos e classificados a partir de testes de controle biológico in vitro. Os resultados evidenciaram o potencial antagonista dos fungos Aspergillus sp., Penicillium sp. e Trichoderma sp. Nenhum desses fungos causou lesões em mudas de E. benthamii.Palavras-chave: Mofo-cinzento; eucalipto; viveiro.AbstractIn vitro selection of endophytes for biological control of Botrytis cinerea in Eucalyptus benthamii. Eucalyptus benthamii is one of the main eucalypt species planted in Southern Brazil, due to its resistance to frost and its use in the production of forest wood for energy purposes. During the production of seedlings, the main disease occurring in forest nurseries is gray-mold caused by the fungus Botrytis cinerea. One alternative for control this disease is biological control with fungal endophytes, which can compete with the foliar pathogens of eucalypt seedlings. The objective of this study was to isolate endophytic fungi from seedlings of Eucalyptus benthamii, identify and select them for B. cinerea control. These were isolated from the interior of disinfected plant tissues, identified according to macro and micromorphological criteria, and based on tests of biological control in vitro. The results revealed the potential antagonist of Aspergillus sp., Penicillium sp. and Trichoderma sp. No fungi caused lesions in E. benthamii seedlings.Keywords: Gray-mold; eucalypt; nursery.    

scholarly journals Antagonismo in vitro por consorcios de Trichoderma sp. y Aspergillus sp. contra el fitopatógeno Sclerotinia sp

2020 ◽  
Vol 19 (1) ◽  
pp. 16-31
Author(s):  
Lena Carolina Echeverry Prieto ◽  
Diego Arturo Zubieta Coronado ◽  
Carlos Alfonso Zafra Mejía
Keyword(s):  
Trichoderma Sp ◽  
Aspergillus Sp

Los hongos como controladores biológicos son importantes en el desarrollo de bioproductos para una agricultura sostenible en el manejo de fitopatógenos como Sclerotinia sp., causante de la podredumbre blanda en cultivos de lechuga, la viabilidad infecciosa en el suelo dura hasta cinco años. El cultivo de lechuga es esencial en la economía agrícola de Colombia y Sclerotinia sp. causa pérdidas hasta el 50% de los cultivos. Por tanto, el objetivo de este trabajo fue evaluar In vitro la capacidad antagónica de tres cepas de Trichoderma sp. B, D y F y tres de Aspergillus sp. A, C y E contra Sclerotinia sp. individualmente y en consorcios. La recuperación, mantenimiento y evaluación de los hongos se realizó en los medios PDA, Jugo V8 y Miel-Avena. Las cepas B, D, F, A, C y E se enfrentaron entre sí y en consorcios contra el fitopatógeno. Los consorcios A+C+B, A+C+D y A+C+F tuvieron un grado de inhibición sobre el fitopatógeno, siendo el más eficiente la combinación A+C+D con un 85% e individualmente las cepas D y A con un 96%. La exploración de hongos como biocontroladores seguirá contribuyendo al conocimiento para el manejo integrado del fitopatógeno de la podredumbre blanda en lechuga.

scholarly journals Antagonismo in vitro por consorcios de Trichoderma sp. y Aspergillus sp. contra el fitopatógeno Sclerotinia sp

2020 ◽  
Vol 19 (1) ◽  
pp. 16-31
Author(s):  
Lena Carolina Echeverry Prieto ◽  
Diego Arturo Zubieta Coronado ◽  
Carlos Alfonso Zafra Mejía
Keyword(s):  
Trichoderma Sp ◽  
Aspergillus Sp

Los hongos como controladores biológicos son importantes en el desarrollo de bioproductos para una agricultura sostenible en el manejo de fitopatógenos como Sclerotinia sp., causante de la podredumbre blanda en cultivos de lechuga, la viabilidad infecciosa en el suelo dura hasta cinco años. El cultivo de lechuga es esencial en la economía agrícola de Colombia y Sclerotinia sp. causa pérdidas hasta el 50% de los cultivos. Por tanto, el objetivo de este trabajo fue evaluar In vitro la capacidad antagónica de tres cepas de Trichoderma sp. B, D y F y tres de Aspergillus sp. A, C y E contra Sclerotinia sp. individualmente y en consorcios. La recuperación, mantenimiento y evaluación de los hongos se realizó en los medios PDA, Jugo V8 y Miel-Avena. Las cepas B, D, F, A, C y E se enfrentaron entre sí y en consorcios contra el fitopatógeno. Los consorcios A+C+B, A+C+D y A+C+F tuvieron un grado de inhibición sobre el fitopatógeno, siendo el más eficiente la combinación A+C+D con un 85% e individualmente las cepas D y A con un 96%. La exploración de hongos como biocontroladores seguirá contribuyendo al conocimiento para el manejo integrado del fitopatógeno de la podredumbre blanda en lechuga.

scholarly journals A Foliar Blight and Tuber Rot of Potato Caused by Phytophthora nicotianae: New Occurrences and Characterization of Isolates

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 492-503 ◽  
Author(s):  
Raymond J. Taylor ◽  
Julie S. Pasche ◽  
Courtney A. Gallup ◽  
H. David Shew ◽  
Neil C. Gudmestad
Keyword(s):  
Late Blight ◽  
Natural Infection ◽  
Phytophthora Nicotianae ◽  
Pink Rot ◽  
Foliar Blight ◽  
Phytophthora Spp ◽  
Commercial Potato ◽  
Potato Foliage ◽  
First Time

Phytophthora spp. are pathogenic to many plant species worldwide, and late blight, caused by Phytophthora infestans, and pink rot, caused by P. erythroseptica, are two important diseases of potato. Another Phytophthora sp., P. nicotianae, was recovered from pink-rot-symptomatic tubers collected from commercial fields in Nebraska, Florida, and Missouri in 2005, 2006, and 2007, respectively. P. nicotianae also was recovered from foliage obtained from commercial potato fields in Nebraska and Texas exhibiting symptoms very similar to those of late blight. Isolates of P. cactorum also were recovered from foliar infections in a commercial potato field in Minnesota in 2005. Natural infection of potato foliage by P. cactorum and infection of wounded potato tuber tissue via inoculation with zoospores of P. capsici are reported here for the first time. Isolates of P. nicotianae, regardless of origin, were primarily of the A1 mating type. All isolates of P. nicotianae and P. cactorum were sensitive to the fungicide mefenoxam. Optimum growth of P. nicotianae, P. erythroseptica, and P. cactorum in vitro occurred at 25°C; however, only P. nicotianae sustained growth at 35°C. Regardless of the tissue of origin, all isolates of P. nicotianae and P. cactorum were capable of infecting potato tubers and leaves. However, isolates of P. nicotianae were less aggressive than P. erythroseptica isolates only when tubers were not wounded prior to inoculation. Pink rot incidence varied significantly among potato cultivars following inoculation of nonwounded tubers with zoospores of P. nicotianae, ranging from 51% in Red Norland to 19% in Atlantic. Phytophthora spp. also differed significantly in their ability to infect potato leaves. Highest infection frequencies were obtained with P. infestans and levels of infection varied significantly among P. nicotianae isolates. The rate of foliar lesion expansion was similar among isolates of P. nicotianae and P. infestans. Whereas P. infestans infections yielded profuse sporulation, no sporulation was observed with foliar infections of P. nicotianae.

scholarly journals Biocontrol in vitro de Uromyces transversalis (Thümen) G. Winter (uredinales: puccinaceae) con hongos antagonistas

2017 ◽  
Vol 7 (7) ◽  
pp. 1639
Author(s):  
Edith Sonia Romero-Orán ◽  
Jesús Gaudencio Aquino-Martínez ◽  
José Francisco Ramírez-Dávila ◽  
Ana Tarín Gutiérrez-Ibáñez
Keyword(s):  
Trichoderma Sp ◽  
Alternaria Sp ◽  
Para Determinar ◽  
Aspergillus Sp

La roya [Uromyces transversalis (Thümen) G. Winter], es una enfermedad que afecta el rendimiento y calidad de la flor del gladiolo en el Estado de México y se combate con fungicidas sintéticos. Por ello, se evaluó la eficiencia del biocontrol in vitro de U. transversalis con hongos antagonistas, además se monitorearon plantaciones de la zona florícola de la entidad, para determinar la severidad de la enfermedad. La actividad antagónica evaluada en condiciones de laboratorio, se realizó en cortes de hojas de gladiolo con pústulas de roya, procedentes de cinco municipios (Villa Guerrero, Zumpahuacán, Malinalco, Jocotitlán e Ixtlahuaca), cortes a los que se les asperjo dos concentraciones de conidios (600 y 300 mL de UFC) de seis cepas de hongos; Cladosporium sp. (ClGl), Alternaria sp. (AltGl), Aspergillus sp. (AspGl) y Trichoderma sp. (TrZA, TrJi y TrPi), con tres repeticiones, bajo un diseño experimental completamente al azar. Los aislamientos TrPi (608.0X106 ml-1 UFC), TrZA (371.2X106 ml-1 UFC) y AltGl (470.4X106 ml-1 UFC), presentaron diferencias significativas con mayor colonización de pústulas. El modo de acción de las cepas antagonistas fue por hiperparasitismo ocasionando hinchamiento, degradación y deformación de uredias y urediosporas. El municipio de mayor porcentaje de infección fue Malinalco con 88.3%, y se reporta oficialmente a Ixtlahuaca y Jocotitlán como municipios infectados por roya transversal. Los mejores aislamientos serán evaluados en campo e invernadero, para poder implementarse en un programa de manejo integrado de roya transversal del gladiolo y fomentar el biocontrol de patógenos.

Insecticidal Active Rotenoids from Plant Parts and Callus Culture of Medicago sativa L. from a Semiarid Region of India (Rajasthan)

2020 ◽  
Vol 16 (6) ◽  
pp. 937-941
Author(s):  
Sharad Vats ◽  
Preeti Mehra
Keyword(s):  
Medicago Sativa ◽  
Callus Culture ◽  
Point Of View ◽  
Semiarid Region ◽  
Disease Vectors ◽  
Vector Borne Diseases ◽  
Plant Parts ◽  
Resistant Varieties ◽  
Medicago Sativa L

Background: Vector-borne diseases are quite prevalent globally and are one of the major causes of deaths due to infectious diseases. There is an availability of synthetic insecticides, however, their excessive and indiscriminate use have resulted in the emergence of resistant varieties of insects. Thus, a search for novel biopesticide has become inevitable. Methods: Rotenoids were isolated and identified from different parts of Medicago sativa L. This group of metabolites was also identified in the callus culture, and the rotenoid content was monitored during subculturing for a period of 10 months. Enhancement of the rotenoid content was evaluated by feeding precursors in a tissue culture medium. Results: Four rotenoids (elliptone, deguelin, rotenone and Dehydrorotenone) were identified, which were confirmed using spectral and chromatographic techniques. The maximum rotenoid content was found in the seeds (0.33±0.01%), followed by roots (0.31±0.01%) and minimum in the aerial parts (0.20±0.05%). A gradual decrease in the rotenoid content was observed with the ageing of subcultured tissue maintained for 10 months. The production of rotenoids was enhanced up to 2 folds in the callus culture using amino acids, Phenylalanine and Methionine as precursors as compared to the control. The LC50 value of the rotenoids was found to be 91 ppm and 162 ppm against disease vectors of malaria and Dracunculiasis, respectively. Conclusion: The study projects M. sativa as a novel source of biopesticide against the disease vectors of malaria and Dracunculiasis. The use of precursors to enhance the rotenoid content in vitro can be an effective venture from a commercial point of view.

scholarly journals Protection of Citrus Rootstocks Against Phytophthora spp. with a Hypovirulent Isolate of Phytophthora nicotianae

2007 ◽  
Vol 97 (8) ◽  
pp. 958-963 ◽  
Author(s):  
G. C. Colburn ◽  
J. H. Graham
Keyword(s):  
Poncirus Trifoliata ◽  
Phytophthora Nicotianae ◽  
Root Weight ◽  
Post Inoculation ◽  
Phytophthora Root Rot ◽  
Phytophthora Spp ◽  
Naturally Occurring ◽  
Fibrous Roots ◽  
Cleopatra Mandarin ◽  
Swingle Citrumelo

Phytophthora root rot of citrus in Florida is caused by Phytophthora nicotianae and P. palmivora. A naturally occurring isolate of P. nicotianae (Pn117) was characterized as hypovirulent on citrus roots. Pn117 infected and colonized fibrous roots, but caused significantly less disease than the virulent isolates P. nicotianae Pn198 and P. palmivora Pp99. Coincident inoculation of rootstock seedlings of Cleopatra mandarin (Citrus reticulata) or Swingle citrumelo (C. paradisi × Poncirus trifoliata) with the hypovirulent Pn117 and the virulent isolates Pn198 and Pp99 did not reduce the severity of disease caused by the virulent Phytophthora spp. When either rootstock was inoculated with the hypovirulent Pn117 for 3 days prior to inoculation with virulent isolates, preinoculated seedlings had significantly less disease and greater root weight compared with seedlings inoculated with the virulent isolates alone. Recovery of the different colony types of Phytophthora spp. from roots of sweet orange (C. sinensis) or Swingle citrumelo was evaluated on semiselective medium after sequential inoculations with the hypovirulent Pn117 and virulent Pp99. Pn117 was isolated from roots at the same level as the Pp99 at 3 days post inoculation. Preinoculation of Pn117 for 3 days followed by inoculation with Pp99 resulted in greater recovery of the hypovirulent isolate and lower recovery of the virulent compared with coincident inoculation.

Effects of Weed Control in Established Alfalfa (Medicago sativa) on Forage Yield and Quality

Weed Science ◽  
1987 ◽  
Vol 35 (4) ◽  
pp. 564-567 ◽  
Author(s):  
Dennis R. Cosgrove ◽  
Michael Barrett
Keyword(s):  
Medicago Sativa ◽  
Weed Control ◽  
Stand Density ◽  
Forage Yield ◽  
Control Measures ◽  
Acid Detergent Fiber ◽  
Yield And Quality ◽  
Herbicide Treatments ◽  
Forage Yields

The effects of weed control measures in established alfalfa (Medicago sativaL.) on forage yield and quality were investigated at three sites with varying alfalfa densities and weed populations. Herbicide treatments were 0.56 and 1.12 kg/ha metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] applied in fall or spring, respectively, 1.68 kg/ha pronamide [3,5-dichloro (N-1,1-dimethyl-2-propynyl)benzamide] applied in fall, and combinations of these treatments. First-harvest forage yields (weeds plus alfalfa) were either reduced or unchanged by herbicide treatments. Total forage yield was not altered by the herbicide treatments, but first-harvest and total alfalfa yield as well as first-harvest forage protein content were increased by several treatments, depending on stand density and weed pressure. Little effect was observed on in vitro digestible dry matter or acid detergent fiber content.

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