Occurrence of Phytoplasma Infection in European Plums (Prunus domestica)

Phytoplasmas were constantly detected by the DAPI technique and by PCR amplification of DNA from European plums (Prunus domestica) cv ‘Susina di Dro’ with symptoms similar to those reported for Japanese plum leptonecrosis. These symptoms included upward rolling of the leaves, which also became bronzed-reddish, thick and brittle, growth of normally dormant axillary buds, off-scason growth during November January and phloem necrosis. Trees with symptoms showed progressive decline. RFLP analysis, revealed that the phytoplasma isolated from the affected plum trees is closely related to the other phytoplasmas present in Prunus species in Europe and can be included in the apple proliferation cluster. Although Japanese plum leptonecrosis is common in Europe. this is the first report of a wide-spread phytoplasma-induced decline in a cultivar of European plum