Sanitary selection of sour cherry cv. Marasca (Prunus cerasus cv. Marasca) in Croatian largest plantation “Vlačine”

Sour cherry cv. Marasca is considered a native Croatian variety with the best fruit quality in Northern Dalmatia region. The current production not sufficient to cover demand, therefore new orchards should be established pathogen-tested planting material. To select virus- and bacteria-free mother trees, survey was conducted largest plantation "Vlačine". ELISA on 205 trees (51 elite, 103 average, 51 below average) confirmed presence of prunus necrotic ringspot virus (PNRSV) 101 (49.3%); petunia asteroid mosaic (PeAMV) prune dwarf (PDV) 10 each (4.9%); raspberry (RpRSV) 7 (3.4%); leafroll (CLRV), arabis (ArMV) plum pox (PPV) 3 (1.5%); apple (ApMV) 1 tree (0.5%). For PNRSV, significant detection sensitivity found, twigs dormant period as more reliable source compared leaves during growing season. In addition, six were positive little 2 (LChV-2) by RT-PCR. Along very frequent latent infections, following symptoms observed pre-harvest period: yellow spots (ApMV); yellowing, stunted growth, leafless only at tip (PDV), bark splitting (PeAMV), reduced leaf size (RpRSV), chlorotic/necrotic ring (PNRSV), uneven ripening (LChV-2). Eleven free all viruses bacteria defined EPPO certification scheme, including PPV. selected elite represent valuable genetic for propagation further clonal selection.