טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentKoren Irit
SubjectAssessment of the Applicability of Bacteriophages Treatment
in Controlling and Preventing Fireblight in
Peer Trees
DepartmentDepartment of Civil and Environmental Engineering
Supervisor Professor Robert Armon
Full Thesis textFull thesis text - English Version


Abstract

Fireblight is one of the most destructive diseases of apple and pear trees. It attacks most species of the family Rosaceae and subfamily Pomoideae - a total of about 180 affected species and is widespread across the globe. The disease is caused by the bacterium Erwinia amylovora. The name of the disease is descriptive of its major characteristics: the brownish aspects of twigs, flowers and leaves as though burned by fire. It also signifies the speed by which the bacterium is able to destroy entire plants and orchards. Today the disease is controlled by a combination of sanitation, cultural practices, and sprays of antibiotics, control agents which for a variety of reasons do not prevent the disease from being an economic threat to the global pome fruit industry.


This research offers a biological control against this pathogen, using specific bacteriophages that are expected to reduce and eliminate the bacterium populations.

Potential for viable usage of bacteriophages as biological control agent has been previously recorded. During this work an attempt was made to identify both local strains of E. amylovora-specific bacteriophages, and a process for optimal performance of the resulting treatment. In addition, various attributes of the discovered bacteriophages, such as survivability and reproduction, were studied.

In trials performed in the field and at the laboratory, locally isolated bacteriophages were subjected to Fireblight-infected pear plants. A range of treatments were used, differing in application method, bacteriophage solution characteristics and host pear plant conditions. The best success rate achieved within the scope of this work was 19.86% reduction in symptoms development, accomplished by spraying a 109 PFU/ml bacteriophage solution on blossoms of 10 years old trees in Dishon orchard.

Identification of specific bacteriophage strains was not successful.