Effect of Setophoma terrestris, Sclerotium cepivorum, and Trichoderma spp. on in vitro onion (Allium cepa) root tissues and the final yield at the field

Author(s):  
William Rivera-Méndez ◽  
Jaime Brenes-Madriz ◽  
Luis Alvarado-Marchena
2018 ◽  
Vol 31 (2) ◽  
pp. 98
Author(s):  
William Rivera-Méndez ◽  
Jaime Brenes-Madriz ◽  
Olga Zúñiga-Vega

La aplicación de Trichoderma spp en el cultivo de la cebolla se ha enfocado principalmente hacia el combate de enfermedades como Sclerotium cepivorum, su principal problema fitopatológico. Con la aplicación de biocontroladores se busca, además de reducir el uso de fungicidas químicos, preparar a la planta desde los primeros estadios del almácigo con la aplicación de filtrados, que fortalezcan y colonicen la raíz, brindándole una protección contra el ataque de los patógenos. El objetivo de esta investigación consistió en determinar los efectos de una cepa nativa de Trichoderma asperellum y un filtrado de metabolitos secundarios sobre el crecimiento de almácigos de cebolla (Allium cepa). La investigación se realizó en dos ciclos de cultivo; uno en el 2015 y otro en el 2016. Se realizaron aplicaciones cada 10 días de los diferentes tratamientos, cada tratamiento consistió de 2 bandejas, cada una con 288 plantas: T 1= T. asperellum preparado al 100%, T2= T. asperellum preparado al 50%, T3= Producto comercial Vitavax®, T4= Testigo, T5= Filtrado al 100% y T6= Filtrado al 50%. En el 2015 solo se probaron los cuatro primeros tratamientos. Para el 2015, se observó que T1 es el mejor tratamiento, ya que mostró un mayor efecto en la elongación y el peso seco radical, así como en el peso fresco de la raíz y el peso seco aéreo. En la elongación de la raíz para el 2016, los tratamientos de T2, T1 y T6 son los que presentaron los mayores tamaños. Con base en lo observado, el tratamiento del filtrado al 50% tiene los mismos efectos que los tratamientos T1 y T2 en todas las variables.


Author(s):  
Martha Delia Ocegueda-Reyes ◽  
Josefina Casas-Solís ◽  
Gil Virgen-Calleros ◽  
Diego Raymundo González-Eguiarte ◽  
Eduardo López-Alcocer ◽  
...  

La pudrición blanca causada por el hongo <em>Sclerotium cepivorum</em> ocasiona grandes pérdidas económicas en el género <em>Allium</em> a nivel nacional. En este trabajo se aislaron, identificaron y caracterizaron tres rizobacterias con efecto antagonico sobre este hongo. Se aislaron 656 bacterias en muestras de suelo de la rizosfera de plantas de cebolla (<em>Allium cepa</em>). Y se evaluó el antagonismo <em>in vitro</em> a <em>S. cepivorum</em>. 23 de estos aislados mostraron actividad antagonica con halos de inhibición superiores a 5 mm; tres de estos fueron mayores a 20 mm, los cuales se seleccionaron, y se identificaron como bacilos Gram positivos, pertenecientes al género <em>Bacillus</em>, <em>B. amyloliquefaciens</em> y <em>B. subtilis</em>. Estas rizobacterias presentaron actividad enzimática de 1-aminociclopropano 1-carboxilato desaminasa, producción de ácido indolacético y sideróforos, tolerancia a NaCl (hasta 7.5%). Las temperaturas de 24 y 37 °C y humedad (50, 75 y 100%) no afectaron el desarrollo bacteriano. De los extractos libres de células obtenidos en diferentes fases de crecimiento, la mayor actividad antifungica sobre <em>S. cepivorum</em> se obtuvo con los extractos de la fase estacionaria (16 a 24 h de incubación). Por los atributos de estas rizobacterias podrían ser consideradas como una alternativa para el control de<em> S. cepivorum</em> en cebolla.


2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.


2013 ◽  
Vol 25 (2) ◽  
pp. 117-120 ◽  
Author(s):  
Bruno Ferreira de Oliveira ◽  
Stela Dalva Vieira Midlej Silva ◽  
Marcos Vinícius Oliveira dos Santos
Keyword(s):  

2020 ◽  
Vol 7 (03) ◽  
Author(s):  
PREM PANDEY ◽  
G. C. SAGAR ◽  
SUNDARMAN SHRESTHA2 ◽  
HIRAKAJI MANANDHAR ◽  
RITESH K. YADAV ◽  
...  

Nine isolates of Trichoderma spp. were isolated from different agro- ecological regions of Nepal viz; Jumla, Palpa, Chitwan, Tarahara, Banke, Illam and Salyan and screened against Sclerotium rolfsii Sacc. Adreded soil borne phytopathogen causing collar rot of chickpea in chickpea; In-vitro efficacy of nine fungal antagonist (Trichoderma spp.) against Sclerotium rolfsii were screened. Pot experiment was done to find out the effective management of S. rolfsi through Tricoderma using different methods i.e. Seed treatment, soil drenching and soil application. All the tested isolates of Trichoderma spp. were found effective on mycelial growth inhibition and sclerotial parasitization of S. rolfsii. Trichoderma isolated from Palpa district showed maximum growth inhibition (%) of pathogen periodically after 48(93.78%), 72(96.00%), 96(97.96%) and 120(100.00%) hours of inoculation. Parasitized sclerotium showed minimum sclerotial germination on agar plates. Moreover, Trichoderma species isolated from Palpa districts showed second best percent mycelial growth inhibition periodically at 72(25.00%), 120(29.16%), 168(29.16%) and 216(29.16%).In pot experiment at 40 days after sowing, Seedling height was maximum in soil drenching with 30g per 100ml of water (22.27cm) and Mortality percentage of seedlings was least or highest disease control was observed in seed treated with 109cfu/ml (0.000%).


2014 ◽  
Vol 40 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Zayame Vegette Pinto ◽  
Matheus Aparecido Pereira Cipriano ◽  
Amaury da Silva dos Santos ◽  
Ludwig Heinrich Pfenning ◽  
Flávia Rodrigues Alves Patrício

Bottom rot, caused by Rhizoctonia solani AG 1-IB, is an important disease affecting lettuce in Brazil, where its biological control with Trichoderma was not developed yet. The present study was carried out with the aim of selecting Trichoderma isolates to be used in the control of lettuce bottom rot. Forty-six Trichoderma isolates, obtained with baits containing mycelia of the pathogen, were evaluated in experiments carried out in vitro and in vivo in a greenhouse in two steps. In the laboratory, the isolates were evaluated for their capabilities of parasitizing and producing toxic metabolic substances that could inhibit the pathogen mycelial growth. In the first step of the in vivo experiments, the number and the dry weight of lettuce seedlings of the cultivar White Boston were evaluated. In the second step, 12 isolates that were efficient in the first step and showed rapid growth and abundant sporulation in the laboratory were tested for their capability of controlling bottom rot in two repeated experiments, and had their species identified. The majority of the isolates of Trichoderma spp. (76%) showed high capacity for parasitism and 50% of them produced toxic metabolites capable of inhibiting 60-100% of R. solani AG1-IB mycelial growth. Twenty-four isolates increased the number and 23 isolates increased the dry weight of lettuce seedlings inoculated with the pathogen in the first step of the in vivo experiments.In both experiments of the second step, two isolates of T. virens, IBLF 04 and IBLF 50, reduced the severity of bottom rot and increased the number and the dry weight of lettuce seedlings inoculated with R. solani AG1-IB. These isolates had shown a high capacity for parasitism and production of toxic metabolic substances, indicating that the in vitro and in vivo steps employed in the present study were efficient in selecting antagonists to be used for the control of lettuce bottom rot.


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