Status of peach American mosaic
The EPPO panel on certification of pathogen-tested fruit trees recently reviewed the status of peach American mosaic (EPPO Al list). It noted that peach latent mosaic (a disease characterized in France and Spain on material imported from USA*) and peach yellow mosaic (in Japan) are both caused by viroids, and that cDNA probes for them are being prepared, and will be compared. There appears to be a strong possibility that peach American mosaic, with very similar symptoms, is also caused by a viroid.
* See Monsion et al. (1989) Acta Horticulturae 235, 247-251; Flores & Llacer (1989) Acta Horticulturae 235, 325-332.