scholarly journals Evaluación in vitro del extracto etanólico de hojas de borraja (Borago officinalis) contra la actividad fungistática

Author(s):  
Juan Esteban Villota Burbano ◽  
Olga Yaneth Vazquez Ochoa

Introducción. Fusarium sp y Alternaria sp son hongos fitopatógenos que causan serios problemas en cultivos y en el sector agrícola, situación que genera pérdidas económicas importantes. Además, debido a la producción de micotoxinas representan una amenaza para la salud de los consumidores y para las plantas. Objetivo. Evaluar la actividad antifúngica del extracto etanólico de hojas de borraja (Borago officinalis) sobre Fusarium sp y Alternaria sp. Materiales y métodos. Se realizó la identificación cualitativa y cuantitativa de los metabolitos secundarios presentes en el extracto etanólico de B. officinalis, posteriormente, Fusarium sp y Alternaria sp.  fueron secuenciadas por estudios moleculares mediante la amplificación de la región ITS (espaciador transcribible interno) del ADN ribosomal y finalmente, se evaluó la actividad antifúngica del extracto sobre las cepas previamente reconocidas mediante la prueba de crecimiento radial por técnica de difusión en agar.  Resultados. El extracto etanólico de las hojas de B. officinalis contiene alcaloides, flavonoides, fenoles,  olifenoles y saponinas, de los cuales los polifenoles y los flavonoides presentan una concentración de 19,08±0,01 miligramos equivalentes de ácido gálico (EAG) por gramo de extracto y 28,12±0,06 miligramos equivalentes de catequina (Qe) por gramo de extracto, respectivamente. La secuenciación de los aislamientos evaluados mostró una alta similitud (>98%) con varias especies de Fusarium sp y Alternaria sp, mientras que los ensayos de actividad antifúngica del extracto mostraron actividad fungistática por parte de B. officinalis al ser 16 mg.l-1 el tratamiento más efectivo para ambos aislamientos evaluados con un porcentaje de inhibición de 90,3±0,9% para Alternaria sp y 86,6±2,2% para Fusarium sp, donde Alternaria sp presentó mayor susceptibilidad frente al extracto de las hojas de B. officinalis. Conclusión. Los resultados de esta investigación proporcionan uno de los primeros reportes de la actividad antifúngica de Borago officinalis sobre Fusarium sp y Alternaria sp.

2019 ◽  
Vol 29 ◽  
pp. 1-11
Author(s):  
Luis Roberto Pérez Moreno ◽  
Luis Pérez-Moreno ◽  
Rafael Guzmán-Mendoza ◽  
Diana Sanzón-Gómez ◽  
José Roberto Belmonte-Vargas

Se evaluó la respuesta in vitro de un aislado de los hongos Alternaria sp., Fusarium sp., Rhizoctonia solani, a 16 agentes biológicos (AB), ocho fungicidas y un testigo. Se usó un diseño experimental completamente al azar con arreglo factorial. El factor A correspondió a los aislados del hongo y el factor B a los productos de control. La comparación de medias se realizó con la prueba de Tukey (p < 0.05). Se hizo la evaluación del crecimiento promedio radial micelial en centímetros (Cprm) cada 24 h durante 11 días. En cualquier caso, no se encontró efecto, solo o en interacción con los agentes de control. Dicloran, Tebuconazol y Cyprodinil-Fludioxonil inhibieron el crecimiento micelial de todos los aislados de los hongos con un promedio final de 1.0 Cprm, y en mayor proporción que los agentes biológicos. Los AB que propiciaron el menor crecimiento micelial de los aislados fueron: Trichoderma sp., Trichoderma harzianum, Microorganismos y Trichoderma viridae.


2021 ◽  
Vol 8 (2) ◽  
pp. 386-391
Author(s):  
Abdulnabi Abbdul Ameer Matrood ◽  
Claudia Adriana Ramírez Valdespino ◽  
Muhannad Abdulridha Al-Waeli ◽  
Mohammad Imad Khrieba ◽  
Abdelhak Rhouma

Recently, a wide range of symptoms including light yellow lesions gradually turning into brown stripes were noticed on date palm leaves in Iraq. In this context, the aim of this study were to isolate the phytopathogens associated with these symptoms, evaluate their pathogenicity and assess the efficacy of two fungicides (Score and Pentanol) under in vitro and in vivo conditions. Two fungal species (Alternaria sp. and Fusarium sp.) were isolated from the symptomatic leaves of date palm. The results of pathogenicity tested proved the ability of Alternaria sp. inoculated separately or in combination with Fusarium sp. to infect the leaves of date palm trees with disease severity index (DSI) values of 67.33% and 65.99%, respectively. The effect of Score (88.76%) and Pentanol (82.91%) against Alternaria sp. was examined by poisoned food technique, which leads a significant increase in mycelial growth inhibition (for 300% of commercial recommended dose of fungicide). Test results indicate that prophylactic spraying of date palm leaves with Score or Pentanol effectively controlled Alternaria sp. with DSI values of 22.65% and 17.87%, respectively. To control Alternaria sp. in field within integrated pest management strategies, chemical control using Score or Pentanol should be taken in consideration.


2010 ◽  
Vol 7 (1) ◽  
pp. 773-783
Author(s):  
Baghdad Science Journal

Three complexes of copper(II) and iron(II) with mixed ligands acetylacetonebis(thio-semicarbazone)- ABTSH2 and benzaldazine- BA have been prepared and characterized using different physico-chemical techniques including the determination of metal contents, mole-cular weight, measurement of molar conductivity, magnetic moment, molar refraction, infrared and electronic spectra. Accordingly, octahedral complexes having general formulaes [Cu2(ABTSH2)2(BA)2Cl2]Cl2 and [M2(ABTSH2)2(BA)2(SO4)2] {M= Cu(II) or (Fe(II)} have been proposed. The resulted complexes screened for antifungal activity in vitro against the citrus pathogen Aspergillus niger and Fusarium sp. which caused root rot of sugar and the beans pathogen Alternaria sp. All the complexes exhibited significant antifungal activities against these pathogens. The antifungal activity of these complexes were comparable with the standard fungicides in ethanol. The complex [Cu2(ABTSH2)2(BA)2Cl2]Cl2 had the best antifungal activity against Alternaria sp.


1987 ◽  
Vol 33 (10) ◽  
pp. 850-856 ◽  
Author(s):  
G. Vannacci ◽  
G. E. Harman

Forty-two microorganisms were tested as biological control agents against Alternaria raphani and A. brassicicola. Tests were conducted for in vitro antagonistic ability, for ability to control the pathogens on naturally infected seeds germinated on moistened blotters, and in planting mix in growth chamber studies, and for their ability to reduce pod infection. The organisms tested were obtained from cruciferous seeds or were strains already identified as being effective against soil-borne Pythium species. The blotter test indicated that six organisms increased both the number of healthy seedlings and the number of seedlings produced from A. raphani infected radish seeds. An additional seven strains improved either germination or increased the number of healthy seedlings. Twenty-nine organisms increased the number of healthy cabbage seedlings from A. brassicicola infected seeds, but total germination was not modified by any treatment. Experiments in planting mix showed that five antagonists (Chaetomium globosum, two strains of Trichoderma harzianum, T. koningii, and Fusarium sp.) increased the number of healthy plants in both radish samples tested, while four additional antagonists provided a significant increase in only one of the samples tested. The five antagonists that consistently increased numbers of healthy radish seedlings also decreased pod infection by A. raphani. None were as effective as iprodrone, however. Several effective antagonists were found to be mycoparasitic against Alternaria spp. Some strains of Trichoderma previously found to be effective against Pythium spp. were also effective against Alternaria spp., indicating that these strains have a wide host range.


2006 ◽  
Vol 30 (2) ◽  
pp. 225-234 ◽  
Author(s):  
Adriana Nanô Sottero ◽  
Sueli dos Santos Freitas ◽  
Arlete Marchi Tavares de Melo ◽  
Paulo Espíndola Trani
Keyword(s):  

Rizobactérias promotoras do crescimento de plantas (RPCPs) podem aumentar a produção agrícola de diversas culturas. O objetivo deste trabalho foi relacionar a colonização radicular e, ou, do colo de plântulas por RPCPs, avaliada in vitro, com sua capacidade de promoção do crescimento, de maneira a agilizar os testes de seleção de isolados de rizobactérias. Além disso, testou-se o antagonismo in vitro entre as bactérias e o fungo Fusarium sp., para verificar a possibilidade de ser a promoção do crescimento exercida por controle biológico de fitopatógeno. Avaliaram-se 64 isolados de rizobactérias do grupo fluorescente de Pseudomonas spp., de diversas origens. A avaliação foi feita visualmente, considerando-se que a presença de uma névoa turva de aspecto esbranquiçado ao longo e em volta da raiz ou de névoa em volta do colo da plântula indicava a colonização das raízes pela bactéria. De todos os isolados bacterianos, apenas oito resultaram em névoa ao longo das raízes e trinta e oito colonizaram a região do colo. Desenvolveu-se também um experimento em casa de vegetação para verificar a capacidade desses isolados de promover crescimento em plantas de alface. O substrato utilizado foi formado por uma mistura de solo e esterco de galinha, semelhante ao usado pelos produtores. Doze isolados promoveram o crescimento das plantas, tendo quatro aumentado a massa de matéria seca da raiz e nove, o número de folhas. Onze isolados que promoveram o crescimento das plantas de alface apresentaram colonização radicular na região do colo. No teste de antagonismo in vitro em meio B de King e em meio BDA, doze dos sessenta e quatro isolados avaliados apresentaram antagonismo contra Fusarium sp., e, desses, apenas três foram eficientes na promoção de crescimento de plantas de alface, tendo colonizado a região do colo das plântulas.


2007 ◽  
pp. 261-265 ◽  
Author(s):  
Igor Stojanov ◽  
Sandra Jaksic ◽  
Jasna Prodanov

Dogs are animals that are most often kept as pets in the cities. Their health problem may be the cause of infections of humans and animals. Skin changes and etiology factors present important segment of the diseases that disturb health of the pets. The objective of this work was mycology examination of scarifications and skin swabs from dogs with clinical symptoms. The aim was to find out which fungi species can be isolated from the changed parts of the skin, and whether is possible that, besides dermatophyte, saprophyte fungi from the environment may also be the cause of the changes, and to reveal their effect on the host. During a one year period, 67 swabs and scarifications from dogs were examined to detect the presence of fungi. The samples were streaked on Sabourdaud's dextrose agar and incubated for 10-21 days at 25?C. In microscopis examination according to their shape, and color, the colonies were identified as conidia, macroconidia and conidiaophora. From 59, of total 67 samples, the following saprophyte fungi were isolated: Aspergillus sp., Penicillium sp., Alternaria sp., Mucor sp. and Fusarium sp. Occurrence of these fungi means that a considerable increase of this microbiological flora may be expected in homes of the owners. This may be the cause of systemic mycosis and allergies in animals and humans, as well as a possibility of contaminated food and incidence of mycotoxicosis.


2016 ◽  
Vol 12 (1) ◽  
pp. 1-8
Author(s):  
Dewi Novina Sukapiring ◽  
◽  
Bonny Poernomo Wahyu Soekarno ◽  
Titiek Siti Yuliani ◽  
◽  
...  
Keyword(s):  

2014 ◽  
Vol 23 (6) ◽  
pp. 3-9
Author(s):  
René Dionisio Cupull-Santana ◽  
Remigio Cortés-Rodríguez ◽  
Ervelio Eliseo Olazábal-Manso ◽  
Carlos Alberto Hernández Medina

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.


2001 ◽  
Vol 41 (5) ◽  
pp. 697 ◽  
Author(s):  
D. R. Beasley ◽  
D. C. Joyce ◽  
L. M. Coates ◽  
A. H. Wearing

Saprophytic bacteria, yeasts and filamentous fungi were isolated from Geraldton waxflower flowers and screened to identify potential antagonism towards Botrytis cinerea. Isolates from other sources (e.g. avocado) were also tested. Isolates were initially screened in vitro for inhibition of B. cinerea conidial germination, germ tube elongation and mycelial growth. The most antagonistic bacteria, yeasts and fungi were selected for further testing on detached waxflower flowers. Conidia of the pathogen were mixed with conidia or cells of the selected antagonists, co-inoculated onto waxflower flowers, and the flowers were sealed in glass jars and incubated at 20˚C. The number of days required for the pathogen to cause flower abscission was determined. The most antagonistic bacterial isolate, Pseudomonas sp. 677, significantly reduced conidial germination and retarded germ tube elongation of B. cinerea. None of the yeast or fungal isolates tested was found to significantly reduce conidial germination or retard germ tube elongation, but several significantly inhibited growth of B. cinerea. Fusarium sp., Epicoccum sp. and Trichoderma spp. were the most antagonistic of these isolates. Of the isolates tested on waxflower, Pseudomonas sp. 677 was highly antagonistic towards B. cinerea and delayed waxflower abscission by about 3 days. Trichoderma harzianum also significantly delayed flower abscission. However, as with most of the fungal antagonists used, inoculation of waxflower flowers with this isolate resulted in unsightly mycelial growth.


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