scholarly journals An assessment of the modulation of the population dynamics of pathogenic Fusarium oxysporum f. sp. lycopersici in the tomato rhizosphere by means of the application of Bacillus subtilis QST 713, Trichoderma sp. TW2 and two composts

2020 ◽  
Vol 142 ◽  
pp. 104158 ◽  
Author(s):  
Maria Alexandra Cucu ◽  
Giovanna Gilardi ◽  
Massimo Pugliese ◽  
Maria Lodovica Gullino ◽  
Angelo Garibaldi
2009 ◽  
Vol 27 (No. 3) ◽  
pp. 203-209 ◽  
Author(s):  
A. Šrobárová ◽  
Š. Eged ◽  
J. Teixeira Da Silva ◽  
A. Ritieni ◽  
A. Santini

Fusaric acid (FA) is one of the most important secondary metabolites produced by <I>Fusarium oxysporum</I> (Schlecht) (FO), <I>F. solani</I> (Mart.) Appel & Wollenweber, and <I>F. moniliforme</I> Sheldon. It is toxic to humans, many plants, and microorganisms and it enhances the toxicity of fumonisin and trichothecene. A simple and rapid method for fusaric acid (FA) screening in <I>Fusarium</I> isolates was developed. In this study, several strains of <I>Fusarium oxysporum</I> were tested for their ability to produce FA by using a suitable race of <I>Bacillus subtilis</I> as the bioassay. A modified method using small agar blocks with the fungus producing FA was applied in the screening test. FA standard and <I>F. culmorum</I> were used as controls. The experimental <I>F. oxysporum</I> isolates and FA standard produced transparent zones on the plates with <I>Bacillus subtilis</I>. The differences in size of the transparent zones corresponded to the quantity of FA when thin-layer chromatography was used.


Author(s):  
Castañeda Alvarez Estefania ◽  
Sánchez Leal Ligia

For farmers the use of agrochemicals is the preferred method to control pests and diseases. Considering the market demand for biological control products, the encapsulation could be a competent alternative to current commercial formulations for cellular viability and controlled release. The purpose of this study was to use ionic gelation with sodium alginate, starch and maltodextrin to immobilize Bacillus subtilis and to evaluate the biocontrol effect against Fusarium oxysporum f. sp. lycopersici in vitro. The matrix with a concentration of 2% sodium alginate, 1% starch, and 1% maltodextrin is a suitable method for cellular viability and biological control activity against Fusarium oxysporum f. sp. lycopersici, with a reduction of mycelial growth of 49.6% and a survival rate for Bacillus subtilis of 98.05% (p less than 0.0001).The use of immobilized bacteria as biological control agents are sustainable and effective bio-inputs that could be used at industrial scale and benefit the tomato crops against attack by Fusarium oxysporum f. sp. lycopersici.


Nova ◽  
2011 ◽  
Vol 9 (16) ◽  
pp. 177 ◽  
Author(s):  
Cristian Layton ◽  
Edna Maldonado ◽  
Luisa Monroy ◽  
Lucía Constanza Corrales Ramírez MSC ◽  
Ligia Consuelo Sánchez Leal MSC

El presente estudio documental evalúa el efecto biocontrolador del género <em>Bacillus sp </em>contra hongos fitopatógenos de plantas, particularmente, a través de relaciones antagónicas inductoras de muerte celular en términos inminentemente naturales. <em>Fusarium oxysporum </em>se encuentra muy relacionado con casos de marchitez vascular y pudrición de raíz en variedad de plantas, obstrucción de los vasos que permiten la circulación vegetal hasta causar amarillamiento de las hojas por imposibilidad en el transporte de nutrientes, causal de grandes pérdidas económicas en el campo agrícola nacional. Se han establecido varios mecanismos para controlar este hongo micelial dentro de las que se encuentran el uso extensivo y variable de agroquímicos y pesticidas, práctica que por sus efectos nocivos con el medio ambiente se ha comenzado a reemplazar por empleo de especies del género <em>Bacillus. </em>La acción biocontroladora de este género bacteriano esta mediada por su perfil bioquímico ya que son productores de múltiples metabolitos biológicamente activos, en el caso de <em>Bacillus subtilis </em>de Iturin A y fengycin y en <em>Bacillus brevis de gramicidina S </em>(1-5) son capaces de inhibir el desarrollo y crecimiento normal de otros microorganismos, lo que sugiere su utilización para el biocontrol de plagas en aras al fortalecimiento de los actuales estándares de calidad en los procesos ambientales.


Author(s):  
Walter Peraza Padilla ◽  
Martha Orozco Aceves ◽  
Alejandro Esquivel Hernández

Se evaluó el parasitismo in vitro de 14 aislamientos de hongos nematófagos (6 Trichoderma sp., 4 Paecilomyces sp., 2 Fusarium oxysporum, y 2 Monacrosporium sp.) contra juveniles y huevos del nematodo agallador Meloidogyne javanica. Los hongos, de 3 regiones productoras de arroz en Costa Rica, (Pacífico Central, Huetar Atlántica y Chorotega), se aislaron mediante el método de espolvoreado en placas, durante abril del 2008 a agosto de 2009. Se utilizó un diseño completamente al azar con 10 repeticiones por hongo, en agar-agua (AA). Se inoculó una suspensión de 1 a 1,5x10 6 conidios (ufc.ml -1 ) por plato Petri, y al cuarto día se depositó en 0,5 ml una suspensión de 150 juveniles y 100 huevos de M. javanica previamente desinfectados, a temperatura ambiente (23-26°C) y con luz natural. Transcurridas 96 h se contó en cada plato el número de nematodos vivos, muertos ó parasi- tados y de huevos parasitados o no parasitados. Se realizó un análisis de regresión logística (RL) para las variables evaluadas, el cual mostró diferencias significativas (p<0,0001) en el desempeño de los hongos evaluados, presentando rangos de entre 10% a 56% en nematodos muertos, de 13% a 79% en nematodos parasitados y de 1% a 96% en huevos parasitados. En general, los hongos del género Trichoderma (Tri1, Tri2, Tri3 y Tri4) fueron los más eficientes en el parasitismo sobre juveniles y huevos de M. javanica.


2019 ◽  
Vol 10 (3) ◽  
pp. 471-483
Author(s):  
Edgar Javier Larios Larios ◽  
José de Jesús Wilmer Valdovinos Nava ◽  
Wilberth Chan Cupul ◽  
Felipe Alejandro García López ◽  
Gilberto Manzo Sánchez ◽  
...  

El objetivo del estudio fue determinar la efectividad de Trichoderma spp. en la reducción de la incidencia del Damping off y promoción del crecimiento vegetativo de plantas de Capsicum chinense (Jacq.) var. “Chichen Itza”. Se evaluó la aplicación foliar, a través de un diseño completo al azar, de dos cepas nativas de Trichoderma sp. (SP6 y Clombta), la co-aplicación de ambas, un producto comercial (Tri-HB®: Trichoderma harzianum y Bacillus subtilis) y un fungicida químico (Captan®). Durante el periodo de estudio, las plantas tratadas con Trichoderma sp. Clombta y con la co-inoculación de Trichoderma sp. Clombta + Trichoderma sp. SP6 no mostraron síntomas de Damping off. Por el contrario, plantas tratadas con Captan® y Tri-HB® mostraron los porcentajes de incidencia acumulada más alta con 5 y 4.5%, respectivamente. Asimismo, a los 28 días después de la germinación, plantas tratadas con Trichoderma sp. Clombta presentaron una mayor altura (11 cm), diámetro de tallo (2.6 mm), biomasa aérea (fresca= 0.8 g planta-1 y seca= 0.13 g planta-1) y volumen radicular (fresca= 0.13 g planta-1 y seca= 0.04 g planta-1), en comparación al resto de los tratamientos evaluados. Para la formación de hojas (9.1 hojas planta-1), área foliar (10.2 cm2) e índice de clorofila (Clombta= 209.9) la aplicación de Trichoderma sp. Clombta destacó de nuevo con los valores más altos (p< 0.05), respecto a las aplicaciones de Captan® y Tri-HB®. De acuerdo a los resultados obtenidos, se determinó que la cepa de Trichoderma sp. Clombta a concentración de 1x1013 conidios mL-1 resultó efectiva para el manejo del Damping off y promoción del crecimiento vegetativo de plantas de C. chinense var. “Chichen Itza”.


2014 ◽  
Vol 13 (3) ◽  
pp. 160-166 ◽  
Author(s):  
Qi-Yao Yang ◽  
Ke Jia ◽  
Wen-Yi Geng ◽  
Rong-Jun Guo ◽  
Shi-Dong Li

3 Biotech ◽  
2020 ◽  
Vol 10 (8) ◽  
Author(s):  
Ramírez-Vigil Emanuel ◽  
Peña-Uribe César Arturo ◽  
Macías-Rodríguez Lourdes Iveth ◽  
Reyes de la Cruz Homero ◽  
Chávez-Avilés Mauricio Nahuam

2000 ◽  
Vol 46 (9) ◽  
pp. 809-816 ◽  
Author(s):  
G A Amer ◽  
R S Utkhede

The effect of various carrier formulations of Bacillus subtilis and Pseudomonas putida were tested on germination, growth, and yield of lettuce and cucumber crops in the presence of Pythium aphanidermatum and Fusarium oxysporum f.sp. cucurbitacearum, respectively. Survival of B. subtilis and P. putida in various carriers under refrigeration (about 0°C) and at room temperature (about 22°C) was also studied. In all carrier formulations, B. subtilis strain BACT-0 survived up to 45 days. After 45 days of storage at room temperature (about 22°C), populations B. subtilis strain BACT-0 were significantly higher in vermiculite, kaolin, and bacterial broth carriers compared with other carriers. Populations of P. putida were significantly higher in vermiculite, peat moss, wheat bran, and bacterial broth than in other carriers when stored either under refrigeration (about 0°C) or at room temperature (about 22°C) for 15 or 45 days. Germination of lettuce seed was not affected in vermiculite, talc, kaolin, and peat moss carriers, but germination was significantly reduced in alginate and bacterial broth carriers of B. subtilis compared to the non-treated control. Germination of cucumber seed was not affected by any of the carriers. Significantly higher fresh lettuce and root weights were observed in vermiculite and kaolin carriers of B. subtilis compared with P. aphanidermatum-inoculated control plants. Lettuce treated with vermiculite, and kaolin carriers of B. subtilis, or non-inoculated control lettuce plants had significantly lower root rot ratings than talc, peat moss, bacterial broth, and P. aphanidermatum-inoculated control plants. Growth and yield of cucumber plants were significantly higher in vermiculite-based carrier of P. putida than the other carriers and Fusarium oxysporum f.sp. cucurbitacearum-inoculated plants.Key words: Bacillus subtilis, Pseudomonas putida, Fusarium oxysporum f.sp. cucurbitacearum, Pythium aphanidermatum, talc, vermiculite, alginate, kaolin, peat moss, wheat bran, oat bran.


Author(s):  
Chandar Kala ◽  
S. Gangopadhyay ◽  
S. L. Godara

Antagonistic potentiality of Trichoderma viride, T. harzianum and Pseudomonas fluorescens were evaluated against Fusarium oxysporum f. sp. ciceri under in vivo conditions. The effect of organic amendments viz; farm yard manure, vermicompost and mustard cake on disease control potentiality of test antagonists against chickpea wilt and on population dynamics of the antagonists and pathogen in soil was also studied. Maximum inhibition of mycelial growth of F. o. f. sp. ciceri was recorded in presence of P. fluorescens (%) followed by T. harzianum (%) and T. viride (%). Seed treatment with P. fluorescens was more effective in suppressing the disease incidence as compared to T. harzianum and T. viride. The disease control efficacy and population dynamics of all the three test antagonists was enhanced in response to application of organic amendments. Among the three organic amendments tested, mustard cake was most effective in enhancing the disease control potentiality of these antagonists.


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