SENSIBILIDADE IN VITRO E IN VIVO DE ISOLADOS DE ALTERNARIA SOLANI A FUNGICIDAS

2020 ◽  
pp. 144-163
Author(s):  
Jessica Caroline Miri ◽  
Janaina Marek
Keyword(s):  
Alternaria Solani

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.

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 Plant-derived antifungal agent poacic acid targets β-1,3-glucan

2015 ◽  
Vol 112 (12) ◽  
pp. E1490-E1497 ◽  
Author(s):  
Jeff S. Piotrowski ◽  
Hiroki Okada ◽  
Fachuang Lu ◽  
Sheena C. Li ◽  
Li Hinchman ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antifungal Agent ◽  
Alternaria Solani ◽  
Phytophthora Sojae ◽  
Antifungal Compound ◽  
Fermentation Inhibitors ◽  
Lignocellulosic Hydrolysates ◽  
Renewable Biomass

A rise in resistance to current antifungals necessitates strategies to identify alternative sources of effective fungicides. We report the discovery of poacic acid, a potent antifungal compound found in lignocellulosic hydrolysates of grasses. Chemical genomics using Saccharomyces cerevisiae showed that loss of cell wall synthesis and maintenance genes conferred increased sensitivity to poacic acid. Morphological analysis revealed that cells treated with poacic acid behaved similarly to cells treated with other cell wall-targeting drugs and mutants with deletions in genes involved in processes related to cell wall biogenesis. Poacic acid causes rapid cell lysis and is synergistic with caspofungin and fluconazole. The cellular target was identified; poacic acid localized to the cell wall and inhibited β-1,3-glucan synthesis in vivo and in vitro, apparently by directly binding β-1,3-glucan. Through its activity on the glucan layer, poacic acid inhibits growth of the fungi Sclerotinia sclerotiorum and Alternaria solani as well as the oomycete Phytophthora sojae. A single application of poacic acid to leaves infected with the broad-range fungal pathogen S. sclerotiorum substantially reduced lesion development. The discovery of poacic acid as a natural antifungal agent targeting β-1,3-glucan highlights the potential side use of products generated in the processing of renewable biomass toward biofuels as a source of valuable bioactive compounds and further clarifies the nature and mechanism of fermentation inhibitors found in lignocellulosic hydrolysates.

scholarly journals Discovery of Cysteine and Its Derivatives as Novel Antiviral and Antifungal Agents

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 383
Author(s):  
Shan Yang ◽  
Tienan Wang ◽  
Yanan Zhou ◽  
Li Shi ◽  
Aidang Lu ◽  
...  
Keyword(s):  
Virus Assembly ◽  
Alternaria Solani ◽  
Phytopathogenic Fungi ◽  
Cercospora Arachidicola ◽  
Antifungal Activities ◽  
Inhibitory Rate ◽  
Commercial Plant ◽  
Protection Activity

Based on the structure of the natural product cysteine, a series of thiazolidine-4-carboxylic acids were designed and synthesized. All target compounds bearing thiazolidine-4-carboxylic acid were characterized by 1H-NMR, 13C-NMR, and HRMS techniques. The antiviral and antifungal activities of cysteine and its derivatives were evaluated in vitro and in vivo. The results of anti-TMV activity revealed that all compounds exhibited moderate to excellent activities against tobacco mosaic virus (TMV) at the concentration of 500 μg/mL. The compounds cysteine (1), 3–4, 7, 10, 13, 20,23, and 24 displayed higher anti-TMV activities than the commercial plant virucide ribavirin (inhibitory rate: 40, 40, and 38% at 500 μg/mL for inactivation, curative, and protection activity in vivo, respectively), especially compound 3 (inhibitory rate: 51%, 47%, and 49% at 500 μg/mL for inactivation, curative, and protection activity in vivo, respectively) with excellent antiviral activity emerged as a new antiviral candidate. Antiviral mechanism research by TEM exhibited that compound 3 could inhibit virus assembly by aggregated the 20S protein disk. Molecular docking results revealed that compound 3 with higher antiviral activities than that of compound 24 did show stronger interaction with TMV CP. Further fungicidal activity tests against 14 kinds of phytopathogenic fungi revealed that these cysteine derivatives displayed broad-spectrum fungicidal activities. Compound 16 exhibited higher antifungal activities against Cercospora arachidicola Hori and Alternaria solani than commercial fungicides carbendazim and chlorothalonil, which emerged as a new candidate for fungicidal research.

scholarly journals Lanthanum in vitro control of Alternaria solani and induction resistance mechanism against blight tomato plant

2021 ◽  
Vol 16 (2) ◽  
pp. 153-158
Author(s):  
Antônio Jussiê da Silva Solino ◽  
Juliana Santos Batista Oliveira ◽  
Sergio Augusto Cesnik ◽  
Kátia Regina Freitas Schwan-Estrada
Keyword(s):  
Mycelial Growth ◽  
Culture Medium ◽  
Early Blight ◽  
Resistance Mechanism ◽  
Alternaria Solani ◽  
Plant Diseases ◽  
Guaiacol Peroxidase ◽  
Specific Catalytic Activity

Rare earth elements have been tested in control of plant diseases. Lanthanum (La) was tested in the control of Alternaria solani (in vitro) and tomato early blight (in vivo) using the concentration 0; 0.1; 0.2; 0.4 and 0.8 g L-1. In vitro, the concentration were diluted in V8 culture medium and evaluated for mycelial growth rate index (MGRI) and pathogen sporulation. In vivo, 24 hours after the application of concentration was inoculate the pathogen and 24 hours after the inoculation, leaflets were collected for quantification, the specific catalytic activity and guaiacol peroxidase. The severity of tomato early blight were also analyzed. As 0.27 and 0.28 g L-1 reduces 28% and 50% the MGRI and the sporulation, respectively. Peroxidase and catalase activity was increased by 298% and 151% in tomato treated with 0.5 and 0.4 g L-1de La, respectively. In vivo reduces AUDPC 70% when was applied 0.27 g L-1 La. Lanthanum can be used as resistance inducer in controlling tomato early blight.

scholarly journals Potential Impact of Fluopyram on the Frequency of the D123E Mutation in Alternaria solani

Plant Disease ◽  
2018 ◽  
Vol 102 (3) ◽  
pp. 656-665 ◽  
Author(s):  
Mitchell J. Bauske ◽  
S. K. R. Yellareddygari ◽  
Neil C. Gudmestad
Keyword(s):  
Disease Control ◽  
Solanum Tuberosum L ◽  
Management Strategies ◽  
Point Mutations ◽  
Fungal Growth ◽  
Alternaria Solani ◽  
Selective Advantage ◽  
Field Trials

Succinate dehydrogenase-inhibiting (SDHI) fungicides have been widely applied in commercial potato (Solanum tuberosum L.) fields for the control of early blight, caused by Alternaria solani Sorauer. Five-point mutations on three AsSdh genes in A. solani have been identified as conferring resistance to SDHI fungicides. Recent work in our laboratory determined that A. solani isolates possessing the D123E mutation, or the substitution of aspartic acid for glutamic acid at position 123 in the AsSdhD gene, were collected at successively higher frequencies throughout a 3-year survey. In total, 118 A. solani isolates previously characterized as possessing the D123E mutation were evaluated in vitro for boscalid and fluopyram sensitivity. Over 80% of A. solani isolates with the D123E mutation evaluated were determined to be highly resistant to boscalid in vitro. However, effective concentration at which the fungal growth is inhibited by 50% values of isolates with the D123E mutation to fluopyram, ranging from 0.2 to 3 µg/ml, were sensitive and only slightly higher than those of baseline isolates to fluopyram, which ranged from 0.1 to 0.6 µg/ml. Five A. solani isolates with the D123E mutation were further evaluated in vivo for percent disease control obtained from boscalid and fluopyram compared with two wild-type isolates, three isolates possessing the F129L mutation, two isolates possessing the H134R mutation, two isolates possessing the H133R mutation, and one isolate with the H278R mutation. Relative area under the dose response curve values for boscalid and fluopyram were significantly lower for all five D123E-mutant isolates, demonstrating reduced disease control in vivo. In field trials, the frequency of A. solani isolates with the D123E mutation recovered from treatments receiving an in-furrow application of fluopyram ranged from 5 to 37%, which was significantly higher compared with treatments receiving foliar applications of standard protectants, in which the frequency of the D123E mutation in isolates ranged from 0 to 2.5%. Results suggest that A. solani isolates possessing the D123E mutation have a selective advantage under the application of fluopyram compared with SDHI-sensitive isolates, as well as isolates possessing other mutations conferring SDHI resistance. These data illustrate the importance of implementing fungicide resistance management strategies and cautions the use of fluopyram for in-furrow applications that target other pathogens of potato.

scholarly journals Occurrence of sdh Mutations in German Alternaria solani Isolates and Potential Impact on Boscalid Sensitivity In Vitro, in the Greenhouse, and in the Field

Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3065-3071 ◽  
Author(s):  
Nicole Metz ◽  
Birgit Adolf ◽  
Nicole Chaluppa ◽  
Ralph Hückelhoven ◽  
Hans Hausladen
Keyword(s):  
Succinate Dehydrogenase ◽  
Early Blight ◽  
Solanum Tuberosum L ◽  
Point Mutations ◽  
Alternaria Solani ◽  
Field Trials ◽  
Sensitivity Testing ◽  
Development Of Resistance

The fungus Alternaria solani is the main pathogen causing early blight on potatoes (Solanum tuberosum L.). An increase in the development of resistance to the succinate dehydrogenase inhibitor (SDHI) boscalid, one of the main active ingredients for the control of early blight, has been reported. For this study, monitoring data from Germany were collected between 2013 and 2016 and an increase in the occurrence of A. solani succinate dehydrogenase (SDH) mutant isolates was observed. In addition to the known point mutations in sdh complex II, a new mutation in subunit C was found in German isolates (SdhC-H134Q). SDHI fungicide sensitivity testing was performed in the laboratory, greenhouse, and field. Reduced boscalid sensitivity was shown for mutant isolates (SdhB-H278Y and SdhC-H134R) both in vitro and in vivo. In addition, field trials with artificial inoculation were performed in 2016 and 2017. In both years, fungicide efficacy was significantly reduced after mutant inoculation compared with wild-type inoculation.

scholarly journals Potenciais alternativas com extratos vegetais no controle da pinta preta do tomateiro

2017 ◽  
Vol 12 (4) ◽  
pp. 687
Author(s):  
Edvan Nilson de Almeida ◽  
Gabriela Silva Moura ◽  
Gilmar Franzener
Keyword(s):  
Allium Sativum ◽  
Alternaria Solani ◽  
Zingiber Officinale ◽  
Santa Cruz

Objetivou-se com o presente estudo avaliar o potencial antifúngico de três espécies de plantas medicinais: Zingiber officinale (gengibre), Allium sativum L. (alho) e Caryophyllus aromaticus L. (cravo-da-índia) in vitro e in vivo, para o controle do patógeno Alternaria solani, agente causal da pinta preta. Avaliou-se in vitro o crescimento micelial, germinação de esporos e o tamanho de tubos germinativos de A. solani nas concentrações de 1,0, 5,0, 10, 15 e 20%. Para a avaliação in vivo sementes de tomateiro cv. Santa Cruz Kada foram semeadas em bandejas de isopor de 200 células contendo substrato comercial. Após 30 dias as mudas foram transplantadas para vasos de 5 L contendo solo e mantidas em casa de vegetação. Os tratamentos para o ensaio em in vivo foram extrato aquoso de gengibre, alho e cravo-da-índia na concentração de 20%. As aplicações foram iniciadas após 47 dias do transplante das mudas para casa de vegetação, sendo realizada uma vez por semana até o momento da colheita. Foram realizadas avaliações da área abaixo da curva de progresso da doença (AACPD), número médio e peso de frutos. Os experimentos foram conduzidos em delineamento inteiramente casualizado, com cinco repetições. Os extratos de cravo-da-índia, alho e gengibre apresentaram efeito inibidor direto sobre o fungo e reduziram a AACPD em 55,8, 29,5 e 22,5% em relação à testemunha água, respectivamente. Esses resultados indicam potencial dos extratos vegetais avaliados no controle da pinta preta do tomateiro, com destaque para o extrato de cravo-da-índia.

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