On-Site Diagnosis of Fire Blight with Antibody-Based Diagnostic Strips

Recently fire blight occurred in the Republic of Korea and eradication program for the disease has been executed since then. Specificity and detection sensitivity of the 2 antibody-based diagnostic strips to Korean isolates of Erwiniaamylovora (Ea) and their application for on-site diagnosis were evaluated in this study. EaAgriStrip, a commercial diagnostic kit, and EB strip, developed in this study, reacted positively to the all tested Korean Ea strains and also to most of Erwiniapyrifoliae (Ep) strains causing black shoot blight. They reacted negatively to all Pusedomonassyringae pv. syringae (Pss) strains that cause shoot blight on apple. Detection sensitivity was similar between the 2 strips. For on-site diagnosis, the two strips reacted positively only to the extractions of the fire-blighted samples on all fire blight occurred orchards except one orchard at which on-site diagnosis was carried out at winter time. In addition, they reacted positively to the black-shoot blighted extractions from the black shoot blight occurred apple orchard. These results suggest that both EB strip and EaAgriStrip would be useful for on-site diagnosis of fire blight in Korea.