[From Peter Schneider on Roses, by Peter Schneider, p. 29:] Mosaic virus produces a pale green or yellow oak-leaf pattern on mature rose foliage... mosaic virus is spread by using infected budding eyes or infected understocks in propagation...

[From A Rose Collection for a Healthy Future, p. 26-28:] rose mosaic [RM] disease is caused by virus(es) and can be detected by a number of techniques...