Relationship and patterns of distribution among grapevine viroids from California and Europe

Analyses of California and European grapevine sources indicated a ubiquitous occurrence of viroids in these materials. Hybridization results indicated sequence homology to both GV-1 and GV-3 for viroids of varieties grown in California as well as from European sources. Wine and rootstock varieties contained a greater proportion of the more common GV-1 plus GV-3 viroid profile, whereas the table varieties contained a larger proportion of the relatively unusual viroid profile of GV-1, -2, and-3. An unexpected divergence of four viroid profiles emerged in the rootstock species. These profiles were 1) Gv-1, -2, and -3, 2) GV-1 plus GV-3, 3) GV-3, and 4) viroid-free. V. californica was the only grapevine analyzed which was found to be viroid-free