FIRE BLIGHT SPREAD IN BULGARIA AND CHARACTERISTICS OF THE PATHOGEN ERWINIA AMYLOVORA

Fire blight in Bulgaria and Erwinia amylovora strains were subjects of field observations and laboratory tests within a 21-year period (1989-2009). Results from the most comprehensive survey for the country determined that fire blight is widely spread and the pathogen was found in 370 localities representing all administrative districts.
The pathogen was isolated from 433 samples originating from 11 rosaceous host species: quince, pear, apple, Mespilus germanica (medlar), Crataegus monogyna, Pyrus sp., P. pyraster, P. elaeаgrifolia, Amelanchier sp., Cotoneaster dammeri and Рyracantha coccinea. The cultural, physiological and biochemical characteristics of more than 370 preserved strains corresponded to the available data on E. amylovora (incl.
API 20E and FAME profiles). Exopolysaccharide production differed among the tested strains, corresponded to virulence, and was particularly high for one strain from (225/12, = BG 16). Numerous DNA tests (23S rDNA, nested PCR, ams-PCR) revealed the existence of E. amylovora-related amplicons and genomic variability (SSR) among the Bulgarian strains as well.
Streptomycin resistance
(100 ppm) was not observed either during laboratory tests of plant samples or in isolates obtained afterwards.

XII International Workshop on Fire Blight

S.G. Bobev, J. van Vaerenbergh, R. Tahzima, M. Maes

spread, hosts, cross inoculations, API 20E, PCR, SSR

https://doi.org/10.17660/ActaHortic.2011.896.17