Grapevines are affected by three major bacterial diseases worldwide, such as bacterial blight (Xylophilus ampelinus), Pierce’sdisease (Xylella fastidiosa) and crown gall (Agrobacterium vitis). These bacteria grow in the vascular system of their host, thus they invadeand colonize the whole plant, independently on symptom development. Latently infected propagating material is a major factor in theirspreading. Therefore the use of bacteria-free planting stock has a basic importance in viticulture. Today several innovative diagnosticmethods, mostly based on polymerase chain reaction, are available to detect and identify bacterial pathogens of grapevines. For production ofbacteria-free plants, the use hot water treatment followed by establishment of in vitro shoot tip cultures is proposed
