SAP-TRANSMISSIBLE VIRUSES IN FLOWERING CHERRY IN NEW-ZEALAND

Six sap-transmitted viruses were identified during a study of 434 flowering cherries in the North Island of New Zealand. These included Prunus necrotic ringspot ilarvirus (PNRSV), apple mosaic ilarvirus (ApMV), flowering cherry virus B (FCVB), strawberry latent ringspot virus (SLRV), prune dwarf ilarvirus (PDV), and flowering cherry virus I (FCVI). Of these, ApMV, FCVB, SLRV, and FCVI were new records for this host. FCVB and FCVI appear to be newly described viruses with characteristics of members of the bromovirus and ilarvirus groups respectively. The most common virus was PNRSV (30.6%); the other viruses ranged in incidence from 10.2% (FCVB) to 0.5% (PDV). A further 43 virus isolates were categorised into nine classes based on symptoms in Chenopodium quinoa and cucumber, and were not further characterised in this study. Repeated sampling of 30 flowering cherry trees during late winter and early spring showed that the enzyme-linked immunosorbent assay (ELISA) was more sensitive for detecting PNRSV infection of flowering cherries than sap transmission, but that neither method was absolutely reliable.