A stem canker of stone fruit trees caused by Staphylococcus warneri

Bacterial canker of stone fruit trees caused by Pseudomonas syringae pv. syringae has become widespread throughout most fruit growing areas of Iran (Abbasi et al 2013). To evaluate the diversity of the strains and possible species inciting the disease in the central areas of the country, surveys were made in 2014 and 2015 in some central provinces including Charmahal-and-Bakhtiary, Isfahan, Qum and Yazd. The twigs and shoots of apricot (Prunus armeniaca), peach (P. persica), plum (P. domestica) and sweet cherry (P. avium) with typical cankers which almost invariably were associated with exudation of gum were collected and brought to the laboratory. The affected shoots were thoroughly washed under tap water. The bark tissues of a segment encompassing a canker were excised and chopped with a sterile razor blade in a few drops of sterile distilled water.