Phenotypic characterization of Erwinia amylovora from pome fruits in Turkey


10th International Workshop on Fire Blight, Bologna, İtalya, 5 - 09 Temmuz 2004, ss.459-461 identifier


Occurrence of fire blight disease was first time observed in Turkey in 1985. Since then it has spread out and caused severe damage on pome fruits, particularly on pear growing in different regions of Turkey based on favorable weather conditions. In the late spring and summer of 2003, an outbreak of fire blight has been observed on quince, but not on apple and pear orchards in the Aegean and Marmara regions of Turkey. Several surveys were conducted to determine the distribution of the disease in the regions in 2003. Diseased samples were collected from affected orchards in different geographical areas in Turkey. A total of 37 Erwinia amylovora strains isolated from pear, apple and wild pear in our collection and 30 putative E. amylovora strains isolated from quince in the present study were characterized on the basis of biochemical, pathological, serological properties and fatty acid methyl ester (FAME) analysis. All strains were Gram-negative, non-fluorescent and produced levan types colonies on sucrose nutrient agar. Hypersensitive reaction on tobacco leaves and milky ooze on immature pear slices were positive. Most (52%) of the strains were copper and streptomycin-resistant. In the pathogenicity tests, apple, pear, quince and wild pear strains induced shoot blight symptoms in apple, pear, and quince plants. All the strains strongly reacted with polyclonal antiserum (Loewe, Cat. Nr. 07069). Identity of the strains was confirmed as E. amylovora based on FAME analysis with similarity indices ranging from 44 to 88%. The strains were divided into two different groups according to cluster analysis of fatty acids. However, no correlation was found between location and host of the strains isolated.