Abstract

During late May and June of 2003, a fire blight epidemic occurred in southcentral Bulgaria on earlier reported hosts such as apple, pear, quince, and hawthorn (1). A new host was found when fire blight was also observed in mid-June on Pyracantha coccinea grown in the Plovdiv Region. Symptoms were necrotic flowers, shoots, petioles, and the presence of sticky ooze droplets mainly on the shoots. Isolations made from blighted Pyracantha coccinea flowers and shoots onto King's medium B (2 days at 25 to 26°C) yielded whitish, glistening, round bacterial colonies. Infiltration of the suspensions of three of the isolates into tobacco leaves resulted in a typical hypersensitive reaction. When Pyracantha coccinea and Cotoneaster sp. shoots were inoculated with these three isolates, typical fire blight symptoms were obtained. The pathogen was reisolated 2 weeks after inoculation from necrotic tissues (15 to 20 mm above and below the inoculation site), thereby fulfilling the Koch's postulates. No symptoms and bacteria were found within any of the shoots from the same plant species injected with sterile water. The identity of the isolates was also determined by conducting nested polymerase chain reaction (PCR) (2) and target-specific PCR (23S rDNA) (3). On the basis of the symptoms, cultural characteristics, and positive results in pathogenicity and PCR tests, the isolates were considered to be Erwinia amylovora. To our knowledge, this is the first report of fire blight on Pyracantha coccinea in Bulgaria.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.