Breeding of plums and prunes resistant to plum pox virus

At Hohenheim we started a plum breeding programme to get new sharka-resista nt cultivars with better fruit quality. In the last years we have recognize d that the resistance of all cultivated plums is based on quantitative crit eria and therefore relative. For this reason we changed our strategy for th e resistance breeding. For the first breeding cycle we used special donors with quantitative resistance. Today, the qualitative resistance is more int egrated. We intend to combine both types of resistance in the hexaploid gen ome of Prunus domestica to obtain an absolute and durable resistance. To ac hieve this aim, we have to consider the evaluation of resistance, the genet ic resources, the inheritance of the resistance and also the breeding metho ds. The results of our resistance breeding study are presented.