scholarly journals The Effect of Temperature Pressure on Multiantagonists Streptomyces sp., Tricho-derma sp. Biological Control of Fusarium oxysporum Wilt Pathogens

2020 ◽  
Plant Disease ◽  
2021 ◽  
Author(s):  
Jie Wang ◽  
Bingyu Cai ◽  
Kai Li ◽  
Yankun Zhao ◽  
Chunyu Li ◽  
...  

Banana Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) is a disastrous fungal disease. Foc tropical race 4 (Foc TR4) infects almost all banana cultivars. Use of chemical fungicides caused seriously environment pollution. Biological control with antagonistic microbes is a promising strategy for controlling Foc TR4. Here, strain WHL7 isolated from marine soft coral exhibited a high antifungal activity against Foc TR4. Based on the morphological and physicochemical profiles as well as the phylogenetic tree, the strain was assigned to Streptomyces sp.. Fermentation broth of Streptomyces sp. WHL7 significantly increased the resistance of banana plantlets to Foc TR4 in the pot experiment. Analysis of antifungal mechanism showed that strain WHL7 extracts inhibited spore germination and mycelial growth of Foc TR4, and destroyed cell integrity and ultrastructure. Hence, Streptomyces sp. WHL7 is an important bioresource for exploring novel natural products and biofertilizer to manage Foc TR4.


1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.


Author(s):  
Tania Ameyally Rios-Hernández ◽  
Alberto Uc-Varguez ◽  
Zahaed Evangelista-Martínez

<em>Fusarium oxysporum</em> causa la pudrición del cormo en gladiolo provocando pérdidas de hasta el 100%. Se seleccionaron aislados de Fusarium a partir de cormos infectados, se identificó morfológica y molecularmente y se seleccionó un aislado a partir de prueba de patogenicidad. Se seleccionó entre 22 aislados de estreptomicetos una cepa que presentó una actividad antagonista del 40% contra <em>Fusarium</em>. Se obtuvo el Extracto Bioactivo (EB) mediante Fermentación en Fase Sólida y se determinó la concentración mínima inhibitoria (MIC) y concentración mínima letal (MLC) por el método de microdilución. Se obtuvo una MIC para el EB de 0.19 mg mL-1 y una MLC de 0.38 mg mL-1, que se confirmó con un ensayo de germinación de microconidios a 8 h, mostrando un porcentaje de inhibición del 17 y 98% para ¼ y ½ de la MIC. Se evaluó el efecto del EB a 1 y 2 MIC’s de concentración contra la pudrición en cormos de gladiolo infectados, obteniendo un efecto protector en los cormos al mantener su dureza después de 15 días, en comparación con el fungicida Carbendazim. Los resultados indican a <em>Streptomyces</em> sp., como un potencial agente de control biológico contra <em>F. oxysporum</em>.


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.


2017 ◽  
Vol 4 (11) ◽  
pp. 66-71
Author(s):  
Valmik M. Patil ◽  
◽  
Kishor R. Patole ◽  
Mohan S. Paprikar ◽  
Jaysingh C. Rajput ◽  
...  

2019 ◽  
Vol 2 (3) ◽  
pp. 89-96 ◽  
Author(s):  
Rachmad Saputra ◽  
Triwidodo Arwiyanto ◽  
Arif Wibowo

Streptomyces sp. bacteria have the potential to produce antibiotic compounds, which are one of the mechanisms that are widely used in biological control. However, in general, biological control mechanisms also occur through competition, cell wall degradation and induced resistance. This study was aimed to determine the physiological, biochemical and molecular characteristics of two isolates of Streptomyces sp. (S-4 and S16 isolates) isolated from the tomatoes roots, and to find out their ability to control Ralstonia solanacearum, which causes bacterial wilt disease on a wide range of hosts. The results showed both Streptomyces sp. isolates had several different physiological and biochemical characteristics and had a different ability to inhibit R. solanacearum in vitro. Streptomyces sp. S-16 isolate had a high similarity with Streptomyces diastaticus subsp. ardesiacus strain NRRL B-1773T based on the molecular identification results. Further research needs to be done to see the potential inhibition of the two Streptomyces isolates in inhibiting the development of bacterial wilt disease in tomato plants caused by R. solanacearum.


2006 ◽  
Vol 3 (1) ◽  
pp. 114-117 ◽  
Author(s):  
Ramandeep Kaur ◽  
Jaspal Kaur ◽  
Rama S. Singh ◽  
C. Alabouvett

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