First report of three filamentous viruses from cherry in Serbia

Abstract

For assessing the sanitary status of stone fruit tree collections from Serbia, 86 sweet cherry and 44 sour cherry cultivars were indexed in Prunus serrulata cv Kwanzan. After 2-3 months in a controlled environment greenhouse, leaf deformation and epinasty, suggestive of infections by Cherry green ring mottle virus (CGRMV) were induced by eight (6 sweet and 2 sour) accessions and a quick decline was induced by 37 other sources. Inoculation with the rest of the cultivars did not elicit any visible reactions. Total nucleic acids were extracted as described by Foissac et al. (2001) from 44 cultivars, selected among those inducing either epinasty (8), or quick decline (16), or no symptoms (20) in the indicator. RT-PCR was done using the following sets of primers: (i) GRM8316 and GRM7950 that amplify a 366 bp DNA fragment from CGRMV; (ii) NEG1U and NEG1L that amplify a 400 bp DNA fragment from Cherry necrotic rusty mottle virus (CNRMV); (iii) ERMUP and ERMLO that amplify a 341 bp DNA fragment from a virus associated with European rusty mottle disease (ERM) (Rott and Jelkmann, 2001). Sixteen of the 44 tested accessions proved to be infected by at least one of the above viruses, four by one, ten by two, and two by all three viruses. The most frequent combination was CGRMV+CNRMV. RT-PCR showed that seven of eight cultivars that indexed positive in P. serrulata by inducing deformation and epinasty were infected CGRMV, which indicates a high level of reliability for woody indexing for this virus. CNRMV and ERM virus were not associated with any particular symptom in Kwanzan. This is the first report of CGRMV, CNRMV and the new elongated virus associated with ERM in Serbia.