The most widespread phytoplasmas, vectors and measures for disease control in Slovenia

Phytoplasmas, as fastidious wall-less mollicutes, colonize phloem tissue of many plant species, including grapevine and fruit trees. They are transmitted between plants by vegetative propagation and by sap-sucking insect vectors, which enable spread of the diseases. During 2001–2010, 3,189 plant and 109 insect samples were collected in targeted surveys and analyzed for the presence of phytoplasmas by molecular methods. Phytoplasmas were found in 1,708 plant samples; in 19 cases mixed phytoplasma infection was identified. The majority of the samples were collected within systematic surveys conducted to determine the prevalence of phytoplasmas in Slovenia. ‘ Candidatus Phytoplasma mali’, associated with apple proliferation, ‘Ca. P. prunorum’, associated with European stone fruit yellows and ‘Ca. P. pyri’, associated with pear decline, were detected in several fruit-growing areas of Slovenia. The most widespread phytoplasma on grapevine in Slovenia was the stolbur phytoplasma, (‘bois noir’). The same phytoplasma was also identified in Convolvulus arvensis and Lycopersicon esculentum. Since 2005, the ‘flavescence dorée’ phytoplasma, associated with serious disease of grapevine, has been reported in Slovenian vineyards. The same phytoplasma was also detected in Clematis vitalba. During the surveys, several known and putative vectors of phytoplasmas were identified.