A Preliminary Account on the Sanitary Status of Stone Fruits at the Clonal Genebank in Harrow, Canada

Abstract

Field observations and laboratory tests were carried out in Harrow to evaluate the sanitary status of the Clonal Genebank collection of stone fruit. The presence of viruses and viroids was determined by ELISA, tissueprinting hybridization and GF305 woody indexing. A total of 645 trees (197 peach and nectarine, 183 sweet and sour cherries, 106 plum, 106 apricot, and 53 other cherries) were tested by ELISA for the presence of Plum pox virus (PPV), Prunus necrotic ring spot virus (PNRSV) and Prune dwarf virus (PDV). No evidence of PPV infection was found in the collection. PNRSV and PDV were frequently detected in single and mixed infections. The overall average of virus infection rate was 20.3%. A total of 336 trees (116 peach and nectarine, 84 sweet and sour cherries, 54 plum, 44 apricot, and 38 other cherries) were tested by tissue printing hybridization for the presence of Peach latent mosaic viroid (PLMVd) and Hop stunt viroid (HSVd). Thirty samples were infected, 28 peaches and nectarines with PLMVd and 2 apricots with HSVd. This is the first report to date, of HSVd presence in Canada. Finally, 114 (38.4%) out of 297 tested accessions were found infected with at least one virus and/or viroid.