The incidence of necrotic ring spot and sour cherry yellows viruses in commercial mazzard and mahaleb cherry rootstocks
Gilmer, R.M.; Kamalsky, L.R.
Plant Dis Reptr 46(8): 583-585
Practically all of the virus contamination on certified nursery trees in New York is derived from infected rootstocks. This report deals with the current incidence of necrotic ring spot (NRSV) and sour cherry yellows (SCYV) viruses in commercially available seedling mazzard (Prunus avium) or mahaleb (P. mahaleb) cherry rootstocks. The incidence of SCYV and NRSV in commercial seedlings was determined by the cucumber-butternut squash- Tithonia indexing technique. Virus incidence in mahaleb seedlings was low (0-4% in the various lots tested), but high in mazzard seedlings, 9 to 33%. Of 186 isolates identified from both mazzard and mahaleb seedlings, 170 (91%) were SCYV.