Detection and characterization of phytoplasmas infecting tomato plants in Greece

Over the course of the 2005 and 2006 growing seasons, surveys were carried out in tomato fields in different parts of Greece in order to determine the occurrence and distribution of phytoplasma diseases of tomato, and to identify and classify the phytoplasmas involved. In all the tomato cultivating areas, the percentage of plants with symptoms resembling phytoplasma infection ranged usually between 1-2%, although in some cases it reached 70-80%. The presence of phytoplasmas in these plants was verified by PCR analysis with universal primers. Further analysis using group specific primers showed that mixed infections with phytoplasmas belonging to the aster yellows (16SrI) or the stolbur (16SrXII-A) group were very common, even in plants showing symptoms typical to either big bud or stolbur disease