Investigation on the plum pox virus resistance in different apricot genotypes

In our three-year investigation, 164 apricot trees of different old German varieties cultivated in the Mansfelder Land region were tested for the plum pox virus (PPV) resistance by double grafting in greenhouse conditions using an isolate of PPV D strain from our region. We selected 25 genotypes with quantitative resistance and two with immunity. The first results of field trials are comparable with those from greenhouse. With cvs. Virosia and Brevira, two local quantitatively resistant varieties will be available from autumn 1998. The origin of both trees, which were found to be immune, is still unclear. They will be used for propagation only after the variety identification.