scholarly journals Bioprospección modulada por la fenología, el sexo y el gradiente altitudinal: el caso de Baccharis conferta sobre Myrothecium roridum y Alternaria solani

2020 ◽  
Vol 98 (3) ◽  
pp. 473-486
Author(s):  
Lázaro Rafael Sánchez-Velásquez ◽  
María Guadalupe Ruiz-Gómez ◽  
Francisco Abelardo Cen-Pacheco ◽  
María del Rosario Pineda-López ◽  
Omar Bravo-Ruiz ◽  
...  
Keyword(s):  
Alternaria Solani ◽  
Myrothecium Roridum

Antecedentes: La bioprospección incluye la búsqueda de metabolitos secundarios para ser usados como fármacos, fungicidas o insecticidas. Los metabolitos secundarios en plantas pueden variar de acuerdo con su estado fenológico, sexo y por el ambiente, por lo tanto, estos elementos deben ser considerados en la bioprospección. Preguntas: 1) ¿Son diferentes las fenofases de Baccharis conferta entre organismos de diferente sexo y a lo largo de un gradiente altitudinal? y 2) ¿Tienen actividad biológica las diferentes concentraciones de extractos etanólicos de diferente sexo, fenofases y altitudes de B. conferta sobre el crecimiento in vitro de Myrothecium roridum y Alternaria solani? Especies estudiadas: Baccharis conferta Kunth, Myrothecium roridum Tode ex Fr. y Alternaria solani Sor. Sitio de estudio y fechas: Parque Nacional Cofre de Perote, septiembre 2017 a octubre 2018. Métodos: Registro mensual de fenofases en plantas de ambos sexos de B. conferta en tres altitudes del Cofre de Perote. Actividad antifúngica in vitro de extractos de B. conferta sobre Myrothecium roridum y Alternaria solani. Resultados: Observamos diferencias (p < 0.05) en la presencia y duración de las fenofases de B. conferta entre sexos y altitudes. También hubo diferencias significativas de los extractos provenientes de organismos de diferentes altitudes y fenofases sobre el crecimiento de M. roridum y A. solani. Conclusiones: Las fenofases de Baccharis conferta son diferentes entre sexos y a través de la altitud, además sus extractos (entre sexos y altitud) tienen efectos diferenciales sobre el crecimiento in vitro de Myrothecium roridum y Alternaria solani.

scholarly journals Efficacy of coupling gamma irradiation with calcium chloride and lemongrass oil in maintaining guava fruit quality and inhibiting fungal growth during cold storage

2018 ◽  
Vol 30 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Ramadan A. Hassanein ◽  
Ehab A. Salem ◽  
Ahmed A. Zahran
Keyword(s):  
Vitamin C ◽  
Fruit Quality ◽  
Cold Storage ◽  
Fungal Growth ◽  
Alternaria Solani ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Γ Irradiation ◽  
Lemongrass Oil

AbstractThis study was performed to explore the efficacy of combining more than one postharvest treatment in maintaining some quality attributes and reducing fungal pathogenicity in cold-stored guava fruits. The investigated postharvest treatments included the control, CaCl2(4%), lemongrass oil (2 dm3kg−1), gamma (γ) irradiation (0.2, 0.4 and 0.6 kGy), 0.4 kGy γ irradiation + CaCl2(4%), and 0.4 kGy γ irradiation + lemongrass oil (2 dm3kg−1). The studied physiochemical attributes included weight loss, decay percentage, fruit firmness, total soluble solids (TSS), titratable acidity (TA), and vitamin C content. Different fungal species were also isolated from decayed fruits and were identified asAlternaria alternata,Alternaria solani,Aspergillus niger,Botrytis cinerea,Fusarium solaniandRhizopus stolonifer. The severity of infection for the different fungi was determined, and anin vitroantifungal assay was conducted for lemongrass oil. All the investigated treatments generally reduced decay and water loss percentages, and controlled TSS, TA and vitamin C decrements that occurred during cold storage. On the other hand, higher irradiation doses generally increased fruit softness, and the 0.4 kGy γ dose did not contribute to the overall fruit quality when coupled with CaCl2and lemongrass oil, compared to CaCl2and lemongrass oil treatments alone.

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 ATIVIDADE DE QUITOSANAS COM DIFERENTES PESOS MOLECULARES SOBRE ALTERNARIA SOLANI

2011 ◽  
Vol 78 (3) ◽  
pp. 459-463 ◽  
Author(s):  
D.S.O. Coqueiro ◽  
R.M. Di Piero
Keyword(s):  
Alternaria Solani

RESUMO A quitosana tem demonstrado potencial antifúngico e de proteção das plantas contra fitopatógenos. O objetivo deste trabalho foi avaliar o efeito antifúngico de quitosanas sobre Alternaria solani, agente causal da pinta preta em tomateiros. Foram utilizadas três quitosanas: uma comercial (Qcom), encontrada em lojas de suplementos alimentares; uma de baixo peso molecular (Qbpm; 50-190 KDa) e outra de médio peso molecular (Qmpm; 190-310 KDa), ambas obtidas da Sigma Aldrich. As quitosanas foram depositadas sobre lâminas escavadas, para avaliar a germinação de conídios e alongamento do tubo germinativo, ou incorporadas ao meio BDA, para avaliar o crescimento micelial de A. solani. Evidenciou-se atividade antifúngica desses polissacarídeos sobre A. solani, com inibição da germinação de conídios e do crescimento micelial de 85% e 50%, respectivamente, quando utilizados em concentrações de 0,125 mg/mL e 0,5 mg/mL. O peso molecular da quitosana não influenciou a atividade antibiótica in vitro.

scholarly journals Antifungal Effects of Zataria multiflora Essential Oil on the Inhibitory Growth of some Postharvest Pathogenic Fungi

2015 ◽  
Vol 7 (4) ◽  
pp. 412-416
Author(s):  
Mahboobeh NASSERI ◽  
Hossein AROUIEE ◽  
Shiva GOLMOHAMMADZADEH ◽  
Mahmoud Reza JAAFARI ◽  
Hossein NEAMATI
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Essential Oil ◽  
Inhibitory Concentration ◽  
Alternaria Solani ◽  
Pathogenic Fungi ◽  
Aspergillus Ochraceus ◽  
Malt Extract ◽  
Zataria Multiflora ◽  
Minimum Fungicidal Concentration

The present study aimed to determine minimum inhibitory concentration and minimum fungicidal concentration of the essential oil of Zataria multiflora to control Alternaria solani, Rhizoctonia solani, Rhizopus stolonifer, Aspergillus flavus, Aspergillus ochraceus and Aspergillus niger. The essential oil of Zataria multiflora was tested in vitro on PDA (malt extract agar medium) with eight concentrations: 0, 10, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 ppm. This investigation followed the completely randomized design (CRD) with three replications. GC-MS evaluations of the essential oil revealed that thymol (35%), carvacrol (34%), cymene-p (9.89%), gamma-terpinene (5.88%) and alpha-pinene (4.22%) were the main compounds of Zataria multiflora oil. The results showed that the essential oil of Zataria multiflora has antifungal activity; the lowest inhibition (75%) was observed in the A. niger, while the highest inhibition (95.3%) was observed in A. solani. Minimum inhibitory concentration for A. solani, R. solani, R. stolonifer, A. flavus, A. ochraceus and A. niger was 200, 200, 200, 300, 300 and 200 ppm respectively. In addition, the present results showed that minimum fungicidal concentration (MFC) for A. solani, R. solani, R .stolonifer, A. niger and A.ochraceus was 600, 400, 300, 900 and 700 ppm respectively and none of the tested concentrations were fatal for A. flavus. A. solani and R. solani showed a strong sensitivity to Zataria multiflora essential oil at all concentrations. Findings of the current study suggest that essential oils of Zataria multiflora could be used for control of postharvest phytopathogenic fungi on fruits or vegetables.

scholarly journals Total Polyphenol Content, in vitro Antifungal and Antioxidant Activities of Callus Cultures from Inula crithmoides

2013 ◽  
Vol 8 (11) ◽  
pp. 1934578X1300801 ◽  
Author(s):  
Anahi Bucchini ◽  
Laura Giamperi ◽  
Donata Ricci
Keyword(s):  
Methanol Extract ◽  
Antioxidant Activities ◽  
Leaf Explants ◽  
Basal Medium ◽  
Alternaria Solani ◽  
Antimicrobial Activities ◽  
Callus Cultures ◽  
Naphthaleneacetic Acid ◽  
Stable Free Radical

This is the first report on the antioxidant and antifungal activities of callus cultures from Inula crithmoides L. (Asteraceae). Callus cultures were initiated from leaf sections, on initial culture MS basal medium supplemented with various concentrations of 2,4-D (2,4-dichlorophenoxyacetic acid), NAA (1-naphthaleneacetic acid) and IBA (indole-3-butyric acid) and a 72% survival was achieved. Significant differences between the various auxins used as phytohormones on callus growth were found. Maximum callusing was noticed on the leaf explants grown on MS basal medium supplemented with 1 mgL–1 2,4-D. Subsequently the antioxidant and antimicrobial activities of the methanol extract from calli were investigated. Antioxidant studies suggested that the methanol extracts of dark-grown and light-grown callus were able to reduce the stable free radical 2,2-diphenyl-1-picrilhydrazyl (DPPH). In the inhibition against lipid peroxidation, extracts of dark-grown callus showed the strongest effect with IC50 values better than those of the standards. The methanol extract of callus cultures had significant antifungal activity only against two of the fungi tested: Alternaria solani and Phytophthora cryptogea. Against all the other tested fungi, the I. crithmoides calli extracts showed fungistatic activity.

scholarly journals Monitoring and Tracking Changes in Sensitivity to Azoxystrobin Fungicide in Alternaria solani in Wisconsin

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 555-560 ◽  
Author(s):  
N. Rosenzweig ◽  
G. Olaya ◽  
Z. K. Atallah ◽  
S. Cleere ◽  
C. Stanger ◽  
...  
Keyword(s):  
Management Practices ◽  
Alternaria Solani ◽  
Wild Type ◽  
In Vitro Sensitivity ◽  
Commercial Potato ◽  
Repeated Applications ◽  
Polymerase Chain ◽  
Sensitivity Changes ◽  
Sensitivity Decrease

Azoxystrobin is a common fungicide used by farmers of Solanaceous crops against Alternaria solani, but there was growing concern about decreased sensitivity with repeated applications. In 2002 and 2003, monitoring of A. solani from commercial potato fields in Wisconsin indicated increased frequency and a statewide distribution of isolates with decreased in vitro sensitivity to azoxystrobin. Mean effective concentration in inhibiting spore germination by 50% values gathered in 2002 and 2003 were approximately 20-fold higher than baseline isolates of A. solani collected in 1998 from fields that had never been treated with azoxystrobin. This sensitivity decrease was correlated with site-specific mutations in the cytochrome b detected by quantitative real-time polymerase chain reaction. The F129L and the G143A substitution have been shown to cause a reduction in sensitivity or resistance, respectively, to quinone outside inhibitors. All of the recovered A. solani isolates collected in 2002 and 2003 were wild type at position 143. However, all three mutations responsible for the F129L substitution (TTA, CTC, and TTG) were detected in our samples. In addition, the frequency of this amino acid substitution in A. solani isolates was statistically different across sampling sites and years, indicating that sensitivity changes depended on specific disease management practices.

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