Articles
Evaluation of the effectiveness of a bacteriophage-based formulation against walnut blight disease caused by Xanthomonas arboricola pv. juglandis in laboratory and field evaluations
Article number
1420_37
Pages
275 – 286
Language
English
Abstract
Xanthomonas arboricola pv. juglandis (Xaj) is a phytopathogen causing walnut blight disease, which means serious damage to plantations, generating economic losses for walnut (Juglans regia L.) producers.
Disease control against Xaj, generally based on copper, are losing efficacy due to resistance acquisition by strains.
An alternative solution to control Xaj and reduce symptomatology of walnut blight could be the application of bacteriophages, small viruses that infect and kill bacteria.
The aim of this study was to evaluate the effectiveness of a bacteriophage-based formulation in laboratory and field trials.
To this, Xaj strains were isolated from infected walnut from Chilean and French fields.
The isolates were identified by PCR with specific primers for Xaj identification.
Subsequently, a laboratory preventive test was carried out in immature walnut fruits.
For this assay, we used the most pathogenic Chilean and French Xaj strains, previously selected for their pathogenicity in walnut leaves.
We inoculated a bacteriophage formulation, composed by three phages (F11, F13 and F31), inside immature walnut fruits and 24 h later the pathogenic bacterium (Chilean strain T3H and French strain Xaj-12) and then we observed infection at 7 and 15 days postinoculation of Xaj.
The results showed that the preventive treatment with our bacteriophage formulation prevents Xaj infection in immature walnut fruits.
Finally, we carried out field trials in walnut plantations in Chile and France.
The Chilean evaluation was performed in a ‘Chandler’ plantation, while the French evaluation was carried out in a ‘Fernor’ walnut orchard.
For comparative purposes, one control without treatment was included in both trials.
We observed that the application of our bacteriophage-base formulations significantly reduces the pathogen pressure, compared to control groups in Chilean trials.
These results suggests that the use of bacteriophages can be an alternative to combat Xaj in walnut plantations.
Disease control against Xaj, generally based on copper, are losing efficacy due to resistance acquisition by strains.
An alternative solution to control Xaj and reduce symptomatology of walnut blight could be the application of bacteriophages, small viruses that infect and kill bacteria.
The aim of this study was to evaluate the effectiveness of a bacteriophage-based formulation in laboratory and field trials.
To this, Xaj strains were isolated from infected walnut from Chilean and French fields.
The isolates were identified by PCR with specific primers for Xaj identification.
Subsequently, a laboratory preventive test was carried out in immature walnut fruits.
For this assay, we used the most pathogenic Chilean and French Xaj strains, previously selected for their pathogenicity in walnut leaves.
We inoculated a bacteriophage formulation, composed by three phages (F11, F13 and F31), inside immature walnut fruits and 24 h later the pathogenic bacterium (Chilean strain T3H and French strain Xaj-12) and then we observed infection at 7 and 15 days postinoculation of Xaj.
The results showed that the preventive treatment with our bacteriophage formulation prevents Xaj infection in immature walnut fruits.
Finally, we carried out field trials in walnut plantations in Chile and France.
The Chilean evaluation was performed in a ‘Chandler’ plantation, while the French evaluation was carried out in a ‘Fernor’ walnut orchard.
For comparative purposes, one control without treatment was included in both trials.
We observed that the application of our bacteriophage-base formulations significantly reduces the pathogen pressure, compared to control groups in Chilean trials.
These results suggests that the use of bacteriophages can be an alternative to combat Xaj in walnut plantations.
Publication
Authors
M.C. Morales, S. Bustos, K. Aguirre, H. Apablaza, M.F. Flores, L. Leymarie Lachaud, M.-N. Hébrard, P. Jargeat, P. Núñez
Keywords
Xanthomonas arboricola pv. juglandis, phage therapy, walnut blight
Groups involved
Online Articles (45)