The spread of Erwinia amylovora bacteria causing fire blight disease on pome fruit trees in central and southern of Syria

Abstract

The fire blight disease caused by the bacteria Erwinia amylovora is the most important diseases affecting fruit trees. The disease was recorded in Syria on apples, pears and quince where the bacteria were isolated and identified without any information about the spread and the damages of the disease. Therefore, the aim of this research was to conduct a preliminary survey of pome fruit trees in central and southern of Syria to investigate and determine the incidence and severity of the disease. This study was carried out during 2009-2010, where 127 fields were investigated, 31of them were infected, which present 24.4% of total fields. The disease was found in Damascus countryside, Deraa, and Sweida. It concentrated in the countryside of Damascus where the proportion of infected fields were 21.4%. The highest severity of the disease found in Kharabo on pears and apples (28.9 % and 17.8% respectively), whereas in Zabadani, the severity on quince was 25.7%. The study showed that the incidence of fields infected was 54.8% on the quince, 33.3% on pears and only 4.76% on apples.105 bacterial isolates were obtained from trees suspected to be infected. Biochemical, serological and pathogenicity tests showed that 58 isolates were identical to Erwinia amylovora, bacterial pathogen of the fire blight disease on fruit trees.