scholarly journals Potencialidade de um actinomiceto de rizosfera de tomateiro como agente de biocontrole de doenças

2009 ◽  
Vol 27 (3) ◽  
pp. 340-344 ◽  
Author(s):  
Renato Carrer Filho ◽  
Reginaldo S Romeiro ◽  
Livio S Amaral ◽  
Flávio AO Garcia
Keyword(s):  
Phytophthora Infestans ◽  
Pseudomonas Syringae ◽  
Ralstonia Solanacearum ◽  
Xanthomonas Campestris ◽  
Alternaria Solani ◽  
Pectobacterium Carotovorum ◽  
Corynespora Cassiicola ◽  
Carotovorum Subsp

Um actinomiceto (Streptomyces setonii, isolado 'UFV-RD1'), obtido de rizosfera de planta sadia de tomateiro, foi selecionado dentre outros 117, como promissor agente de biocontrole de enfermidades da cultura. Em testes de antagonismo in vitro contra patógenos do tomateiro, o isolado 'UFV-RD1' foi incapaz de inibir o crescimento de bactérias (Pseudomonas syringae pv. tomato, Ralstonia solanacearum, Pectobacterium carotovorum subsp. carotovorum, Xanthomonas campestris pv. vesicatoria) mas inibiu a germinação de conídios de alguns fungos (Alternaria solani, Phytophthora infestans, Corynespora cassiicola, Stemphylium solani). Em ensaios de biocontrole experimental in vivo, em casa de vegetação, o actinomiceto foi efetivo em reduzir a severidade de sintomas no caso de patógenos fúngicos e bacterianos testados como desafiantes. A campo, quando A. solani e P. infestans ocorreram naturalmente, as plantas originárias de sementes microbiolizadas com propágulos da estirpe 'UFV-RD1' exibiram sintomas menos severos que as plantas controle para o caso da pinta preta. O agente de biocontrole é promissor para futuros protocolos de manejo integrado, como forma de reduzir a quantidade de defensivos utilizados.

scholarly journals Métodos de isolamento de bactérias do filoplano de tomateiro visando populações específicas e implicações como agentes de biocontrole

2004 ◽  
Vol 29 (6) ◽  
pp. 638-643 ◽  
Author(s):  
Bernardo A. Halfeld-Vieira ◽  
Reginaldo S. Romeiro ◽  
Eduardo S.G. Mizubuti
Keyword(s):  
Lycopersicon Esculentum ◽  
Phytophthora Infestans ◽  
Pseudomonas Syringae ◽  
Alternaria Solani ◽  
Xanthomonas Vesicatoria

Em um processo de seleção de bactérias do filoplano de tomateiro (Lycopersicon esculentum) com potencial para o controle de doenças da parte aérea da cultura, diferentes métodos de isolamento foram utilizados visando obter isolados da população total, da população da superfície foliar e isolados que habitam locais protegidos do filoplano e/ou que toleram fatores de estresse. Foi testada a capacidade de 300 isolados em controlar in vivo, as doenças causadas por Alternaria solani, Pseudomonas syringae pv. tomato e Phytophthora infestans. Os testes foram repetidos para cada um dos antagonistas selecionados, estudando-se, também, a capacidade de controlar a mancha-bacteriana, causada por Xanthomonas vesicatoria. Os resultados demonstraram haver predomínio de antagonistas provenientes de folíolos do terço superior da planta de população total ou da superfície. Entretanto, o único antagonista selecionado, isolado de folíolos do terço inferior, foi obtido de locais protegidos do filoplano e/ou capaz de tolerar fatores de estresse.

scholarly journals Bioassay-Guided Isolation of Broad-Spectrum Fungicidal Active Compound from Artemisia ordosica

Metabolites ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 629
Author(s):  
Gaijuan Tang ◽  
Shuyu Yang ◽  
Wenqiong Hu ◽  
Jingyi Jiang ◽  
He Yan ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Broad Spectrum ◽  
Xanthomonas Campestris ◽  
Tomato Fruit ◽  
Pathogenic Fungi ◽  
Erwinia Carotovora ◽  
Artemisia Ordosica ◽  
Active Compounds

To avoid the widespread resistance of commercial fungicides, new broad-spectrum botanical fungicides need to be developed. In previous bioactive screening assays, extracts of Artemisia ordosica Krasch. (A. ordosica) had highly antifungal activities, but the responsible phytochemicals were unidentified. In this study, active compounds of A. ordosica extracts were identified using a bioassay-guided method, and antifungal assays were performed in vitro and in vivo. The bioactive compounds were dissolved in petroleum ether, and the best antifungal fraction contained four compounds: trans-dehydromatricaria ester (TDDE), 7, 4-demetylnringenin, capillarin, and stearic acid. Among them, TDDE exhibited the highest antifungal activity against six pathogenic fungi and five bacteria. It exhibited significant fungicidal activity against Thanatephorus cucumeris and Botrytis cinerea with EC50 values of 0.464 μg/mL and 1.4 μg/mL, respectively. The living tissue bioassay results showed that the relative protection effects (RPE) of TDDE on tomato leaves, tomato fruit, and strawberry leaves infected with B. cinerea reached 76.78%, 86.2%, and 80.89%, respectively. In pot experiments, the RPE on tomato and strawberry plants infected with B. cinerea reached 84.11% and 96.37%, respectively. Morphological and physiological examination showed that TDDE had significant inhibitory effects on mycelial growth, including increased top offshoot, contorted hyphal tips, and extravasated cytochylema. Meanwhile, bactericidal activities of TDDE were significantly higher than kanamycin and streptomycin in five bacteria, and the plant tissue experiments further demonstrated that it had an 88.31% RPE on walnut leaves infected with Xanthomonas campestris pv. jugiandis, 72.18% RPE on potato infected with Erwinia carotovora subsp. carotovora, and 82.50% RPE on kiwifruit branches infected with Pseudomonas syringae pv. actinidiae. The active compounds isolated from A. ordosica in this study show great potential value for developing broad-spectrum fungicides, and also provide an important way to identify and isolate new bioactive products from medicinal plants.

scholarly journals Punica granatum L. extract contributes to phytopathogens control and enhances Eruca vesicaria (L.) Cav. germination in vitro and in vivo

2021 ◽  
Vol 35 (3) ◽  
pp. 217-231
Author(s):  
Suzanna de Sousa Silva ◽  
Patrícia Costa dos Santos Alves ◽  
Denise Fernandes Coutinho ◽  
Tássio Rômulo Silva Araújo Luz ◽  
Guilherme Martins Gomes Fontoura ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Xanthomonas Campestris ◽  
Punica Granatum ◽  
Fruit Peel ◽  
Plant Disease Control ◽  
Carotovorum Subsp ◽  
Agar Well Diffusion Assay ◽  
Dose Dependent

The study aimed to investigate antimicrobial activity of the hydroalcoholic crude extract from the fruit peel of Punica granatum (Pp) and punicalagin compound (Pg) on phytopathogenic bacterial isolates and its potential use as a sustainable alternative in treatment of vegetable seeds. The antimicrobial activity in vitro was tested by agar well diffusion assay and through viability tests in liquid medium. In vivo treatment with Pp was tested on Eruca vesicaria seeds infected with Xanthomonas campestris pv. campestris. Pp induced the formation of large inhibition zones to the growth of the tested pathogens (35.33 mm – 6.66 mm), with dose-dependent effect. Viability tests confirmed the antimicrobial activity of the Pp on X. campestris pv. campestris and P. carotovorum subsp. carotovorum with minimum inhibitory concentration (MIC) of 125 μg/mL. Punicalagin compound presented MIC of the 31.25 μg/mL. The seed treatment with Pp indicated control of pathogen-induced symptoms in seedlings of the E. vesicaria and positive effect in seed germination, emergence and in stomatal functionality. The results indicate strong potential of the extract from the fruit peel of P. granatum and Punicalagin for formulating botanical pesticides for plant disease control.

scholarly journals In VitroActivity of Glucosinolates and Their Degradation Products against Brassica-Pathogenic Bacteria and Fungi

2014 ◽  
Vol 81 (1) ◽  
pp. 432-440 ◽  
Author(s):  
T. Sotelo ◽  
M. Lema ◽  
P. Soengas ◽  
M. E. Cartea ◽  
P. Velasco
Keyword(s):  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Degradation Products ◽  
Allyl Isothiocyanate ◽  
Leaf Extracts ◽  
Soil Pathogens ◽  
Content Type ◽  
Positive Effects

ABSTRACTGlucosinolates (GSLs) are secondary metabolites found inBrassicavegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about theirin vitrobiocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enrichedBrassicacrops on suppressingin vitrogrowth of two bacterial (Xanthomonas campestrispv. campestris andPseudomonas syringaepv. maculicola) and two fungal (AlternariabrassicaeandSclerotiniascletoriorum)Brassicapathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of differentBrassicaspecies, have potential to inhibit pathogen growth and offer new opportunities to study the use ofBrassicacrops in biofumigation for the control of multiple diseases.

scholarly journals Efeito de extratos vegetais de plantas do Cerrado para controle de pinta-preta em tomateiro

2018 ◽  
Vol 44 (2) ◽  
pp. 189-192
Author(s):  
Bruna Fukumoto Kobayashi ◽  
Daniel Rufino Amaral
Keyword(s):  
Alternaria Solani

RESUMO A “Mancha de Alternaria” causada pelo fungo Alternaria solani é uma das principais e mais frequentes doenças que incidem na cultura do tomate. Manifesta-se nas hastes, caule e principalmente nas folhas, e em alta severidade. Causa desfolha e também pode provocar infecções nos frutos, tornando-os impróprios para comercialização. Para controle da doença, os defensivos sintéticos ainda são os mais utilizados. Visando a diminuição da toxicidade ao meio ambiente e à saúde humana, surge a busca pela utilização de produtos alternativos para o controle de doenças. O objetivo do trabalho foi avaliar o efeito de extratos vegetais para o controle de Alternaria solani na cultura do tomateiro: in vivo e in vitro. O experimento foi conduzido em duas etapas: 1- in vivo (em casa de vegetação em sistema hidropônico) e 2- in vitro (em laboratório). Os tratamentos utilizados na primeira etapa foram: 1- Testemunha (sem aplicação); 2- Extrato de Assa peixe; 3- Extrato de Aroeirinha; 4- Extrato de Pata de Vaca do Cerrado; 5- Extrato de Murici, sendo estes na concentração de 10% do extrato diluído em água e outra testemunha no qual foi aplicado um fungicida (Piraclostrobina). O delineamento experimental foi em blocos ao acaso com quatro repetições. Na segunda etapa, o experimento foi conduzido em delineamento inteiramente casualizado, sendo os mesmos tratamentos da primeira, exceto o tratamento comercial. Observou-se que os extratos a base de Aroeirinha e Assa Peixe, proporcionaram controle de mancha de alternaria em plantas de tomate no experimento in vivo. Já para o experimento in vitro, pode-se observar que o extrato de Murici e Aroeirinha diminuíram o crescimento micelial do fungo.

Bactericidal and Fungicidal Activities of Calia secundiflora (Ort.) Yakovlev

2008 ◽  
Vol 63 (9-10) ◽  
pp. 653-657 ◽  
Author(s):  
Dolores Pérez-Laínez ◽  
Rosario García-Mateos ◽  
Ruben San Miguel-Chávez ◽  
Marcos Soto-Hernández ◽  
Enrique Rodríguez-Pérez ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Alternaria Solani ◽  
Erwinia Carotovora ◽  
Phytopathogenic Fungi ◽  
Quinolizidine Alkaloids ◽  
Liquid Chromatography Mass Spectrometry ◽  
In Vitro Bioassay ◽  
Organic Extract ◽  
Phytopathogenic Fungi And Bacteria

Calia secundiflora (Ortega) Yakovlev (Fabaceae) is considered a medicinal plant in Mexico but has scarcely been used because of the toxicity of its quinolizidine alkaloids. Several quinolizidine alkaloids have shown bactericidal, nematicidal, and fungicidal activities. The purpose of this study was to identify the alkaloids in the seeds and evaluate the activity of the organic extract on several phytopathogenic fungi and bacteria. An in vitro bioassay was conducted with species of the following phytopathogenic fungi: Alternaria solani, Fusarium oxysporum and Monilia fructicola; and of the following bacteria Pseudomonas sp., Xanthomonas campestris and Erwinia carotovora. Cytisine, lupinine, anagyrine, sparteine, N-methylcytisine, 5,6-dehydrolupanine, and lupanine were identified by liquid chromatography-mass spectrometry in the extract of seeds; the most abundant compound of the extract was cytisine. It was observed that the crude extract of Calia secundiflora was moderately active on bacteria and more potent on phytopathogenic fungi. In contrast cytisine showed the opposite effects.

scholarly journals Keefektifan Bakteri dan Khamir Asal Air Rendaman Kompos dalam Menekan Perkembangan Penyakit Bercak Coklat (Alternaria solani Sorr.) pada Tomat

Agrikultura ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 52
Author(s):  
Noor Istifadah ◽  
Putu Ghita Novilaressa ◽  
Fitri Widiantini ◽  
Sri Hartati
Keyword(s):  
Alternaria Solani

Penyakit bercak coklat yang disebabkan oleh jamur Alternaria solani Sorr. merupakan salah satu penyakit penting pada tanaman tomat. Cara pengendalian penyakit bercak coklat yang biasa dilakukan adalah dengan penyemprotan fungisida sintetik. Mengingat berbagai dampak negatif dari penggunaan pestisida yang terus-menerus, maka perlu dikembangakan cara pengendalian ramah lingkungan seperti pengendalian secara biologi. Bakteri dan jamur merupakan mikrob yang berpotensi sebagai agens biokontrol penyakit tanaman. Salah satu sumber dari agens antagonis patogen tanaman adalah air rendaman kompos. Paper ini mendiskusikan hasil penelitian yang mengevaluasi kemampuan bakteri mikrob yang diisolasi dari air rendaman kompos berbahan dasar kotoran sapi dan domba untuk menghambat pertumbuhan A. solani in vitro dan menekan penyakit yang disebabkan patogen tersebut pada buah dan tanaman tomat. Percobaan secara in vitro menggunakan Rancangan Acak Lengkap, sementara pengujian pada buah dan tanaman tomat menggunakan Rancangan Acak Kelompok. Isolasi mikrob dari air rendaman kompos berbahan dasar kotoran sapi dan domba menghasilkan 35 isolat, yang mana 11 isolat (enam isolat bakteri dan lima isolat khamir) dapat menghambat pertumbuhan A. solani secara in vitro sebesar 79,3%-84,2% dengan zona hambat sebesar 0,0-28,3 mm. Pada pengujian secara in vivo, lima isolat non-patogenik (dua isolat bakteri dan tiga isolat khamir) dapat menekan penyakit bercak coklat pada buah tomat sebesar 100% dan pada daun tomat sebesar 77,5%-98,1%. Isolat-isolat ini berpotensi untuk dikembangkan lebih lanjut sebagai agens biokontrol penyakit bercak coklat pada tanaman tomat.

scholarly journals Uso de antibióticos e leveduras para controle da podridão-mole em couve-chinesa

2011 ◽  
Vol 29 (1) ◽  
pp. 78-83 ◽  
Author(s):  
MRF Mello ◽  
EB Silveira ◽  
IO Viana ◽  
ML Guerra ◽  
RLR Mariano
Keyword(s):  
Pectobacterium Carotovorum ◽  
Carotovorum Subsp ◽  
Brassica Pekinensis

A podridão-mole causada por Pectobacterium carotovorum subsp. carotovorum (Pcc) pode ocorrer em plantios de couve-chinesa (Brassica pekinensis) com até 67% de incidência. O trabalho visou avaliar a sensibilidade in vitro de Pcc a bactericidas, o efeito de Mycoshield® nas dosagens de 3,0 e 1,5 g L-1, e de leveduras a 10(8) cel/mL no controle da doença em casa de vegetação e em campo. As plantas foram pulverizadas com Mycoshield® (oxitetraciclina 20%) e leveduras (Rh1 e Rh2 (Rhodotorula spp.) e Sc1 (Saccharomyces cerevisae)) sete dias após o transplante, e inoculadas por picada com o isolado Pcc120, sete dias e 12 h após o tratamento, respectivamente. Em todos os experimentos foram avaliados os componentes epidemiológicos da doença. In vitro, 40 isolados de Pcc testados apresentaram resistência ao sulfato de cobre e sensibilidade a oxitetraciclina, estreptomicina, oxitetraciclina+estreptomicina e oxitetraciclina+sulfato de cobre, todos na concentração de 0,2 g L-1. Seis isolados de Pcc foram mais inibidos por Mycoshield® do que por Agri-Micina® (oxitetraciclina 1,5% + estreptomicina 15%) ambos a 3,0 g L-1, não sendo inibidos por Kasumin® (casugamicina 2%) (2,0 mL L-1). Em casa de vegetação, Mycoshield® (3,0 g L-1) reduziu a severidade e o índice de doença em até 47,4 e 19%; já a levedura Sc1 reduziu a severidade da doença e a área abaixo da curva de progresso da doença (AACPD) em até 27,6 e 39,3%, respectivamente, enquanto Rh1 reduziu a AACPD em até 33,5%. Em campo, Mycoshield® reduziu o índice de doença (14,4%) a severidade (15,5%) e a AACPD (28,9%); enquanto que Rh1 reduziu o índice de doença (8,8%) e Sc1 reduziu a AACPD (15,7%). Conclui-se que o Mycoshield® e as leveduras apresentaram baixa eficiência para controle da podridão-mole da couve-chinesa em campo.

scholarly journals Respuesta de biosurfactantes producidos por Pseudomonas fluorescens para el control de la gota de la papa Phytophthora infestans (Mont) de Bary, bajo condiciones controlada.

2010 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Hugo F. Rivera ◽  
Erika P. Martínez ◽  
Jairo A. Osorio ◽  
Edgar Martínez
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Pseudomonas Fluorescens ◽  
Negative Impact ◽  
Potato Late Blight ◽  
Pathogen Resistance ◽  
Production Costs ◽  
In Vitro Assays

<p>Phytophthora infestans (Mont.) de Bary, agente causal de la gota de la papa, es considerado la principal limitante de la producción de este cultivo en Colombia. El control habitual del patógeno se realiza con fungicidas de tipo sistémico, que incrementan los costos de producción, pueden inducir la resistencia del patógeno y tiene un impacto negativo en el ambiente. Por tanto, se llevó a cabo este estudio con el propósito de buscar alternativas amigables con el ambiente, que hagan parte de un paquete tecnológico eficaz de control. Dos cepas nativas de Psedomonas fluorescens (039T y 021V), provenientes de cultivos de papa, fueron evaluadas contra P. infestans. Las suspensiones bacterianas y los biosurfactantes parcialmente purificados (BPP), producidos por éstas (obtenidos en medio mínimo de sales con querosén), fueron aplicados sobre foliolos desprendidos en ensayos in vitro y experimentos in vivo en plantas de papa, en condiciones controladas en casa de malla. Los resultados demostraron la capacidad que tienen los biosurfactantes y las suspensiones bacterianas para controlar al patógeno, ya que el BPP 039T logró reducir el nivel de severidad de la enfermedad en 79,9% in vitro y 38,5% in vivo, mientras que el BPP 021V redujo en 78,7% in vitro y 30,2% in vivo. Las suspensiones bacterianas redujeron el nivel de severidad en 72,4% (039T) y 66,1% (021V) en las evaluaciones in vitro y 35% en los experimentos in vivo. Los resultados de esta investigación muestran el potencial que tienen los biosurfactantes para el control de la gota en Colombia.</p><p> </p><p><strong>Evaluation of Biosurfactants Produced by Pseudomonas fluorescens for Potato Late Blight Control (Phytophthora infestans (Mont) de Bary) Under Controlled Conditions</strong></p><p>Phytophthora infestans (Mont.) de Bary, causal agent of potato late blight is considered the main limiting pathogen for the production of this crop in Colombia. The usual control of the disease has been performed with systemic fungicides which increase production costs, can induce pathogen resistance and have a negative impact on the environment. Therefore, this study was carried out in order to find effective and environmentally friendly control alternatives for potato late blight. Two Pseudomonas fluorescens native strains (039T and 021V) isolated from potato crops were evaluated against P. infestans. Bacterial suspensions (obtained from minimal salts medium added with kerosene) and partially purified biosurfactants (BPP) were applied on detached leaflets for in vitro assays and on potato plants in greenhouse, for in vivo assays and the measure of inhibitory effect of the disease was assessed. The results showed the ability of P. fluorescens biosurfactants and bacterial suspensions to control the pathogen. BPP 039T was able to reduce the level of severity disease by 79.9% in vitro and 38.5% in vivo, whereas BPP 021V decreased 78.7% in vitro and 30.2% in vivo. Bacterial suspensions reduced the severity level in 72.4% (039T) and 66.1% (021V) in vitro assessments and 35% in the in vivo experiment. These results show the potential of P. fluorescens biosurfactants to control the potato late blight in Colombia.</p>

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