C. Dadu, L. Prodaniuc, Iu. Kalashyan and A. ChernetsThe technology of in vitro micropropagation of the apple rootstock MM 106 was developed. From 80 to100% rooting was obtained in variants with indole-3-butyric acid (IBA) 1-2 mg/l. A diagnostic polyclonal antiserum to the apple stem pitting virus (ASPV) was obtained. The results of the virus elimination of apple cultivars 'Coreor', 'Coredova', 'Coretard', 'Izvoras' genetically resistant to scab Venturia inaequalis Cooke Wint using methods of thermotherapy are described. The virus free clone’s category Prebase were planted in the depozitarium of the institute in order to increase and preserve the virus-free genefond of pome fruit crops.