In 2016, necrosis symptoms was observed on stem and flower of red poppy (Papaver rhoeas) in Hamadan prov-ince of Iran. Symptomatic samples were collected and suspi-cious bacterial agent was isolated on nutrient agar medium. The phenotypic features of the bacterial strains were charac-terized and some molecular traits were examined. The bacte-rial strains phenotypically showed a high similarity to the members of Enterobacteriaceae, in particularErwinia piriflorinigrans. All tested strains were pathogenic on red poppy and blossoms of pear under greenhouse condition. The phylogenetic analysis based on 16S rRNA andatpD genes sequences showed that representative strains were very similar toErwinia piriflorinigrans. This is the first report of the presence of Erwinia piriflorinigransas a causal agent of flower necrosis of red poppy worldwide.
