LAUSR

Prunus species are prone to infections by a range of pathogens (LAIMER 2002). Stone fruit plantations are mainly affected by Plum pox virus (PPV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV) and European Stone Fruit Yellows phytoplasma (ESFY). The production of elite plants of pathogen-free stone fruit cultivars includes the application of effective methods for the detection and elimination of the major stone fruit tree viruses and phytoplasmas. The method of micropropagation offers a quick possibility for breeders to introduce new cultivars into the production. Virus testing by molecular techniques of in vitro plants requires only tiny samples and reduces the danger of false negatives. First results of the virus testing originated from in vitro peach cultivars are presented.