Occurrence and Distribution of Shallow Bark Canker of Walnut Trees in Damavand

In recent years, Shallow bark canker (Brenneria nigrifluens) of walnut trees has become fairly widespread in Iran. To determine the distribution of the disease in Damavand, from summer of 2013, bark samples were collected from walnut trees showing symptoms of Shallow bark canker. 46 strains of bacteria were isolated from infected tissues. Strains appeared similar in phenotypic characteristics. On the basis of the morphological and biochemical results and sequencing of RNA polymerase beta sub unit gene the bacterium was identified as Brennerianigrifluens. This is the first report of Shallow bark canker of walnut trees in Damavand.