The most common viruses infecting roses are a group of viruses that can cause yellow patchwork patterns on the leaves - - thus the name, Rose Mosaic Virus. These viruses also infect other plants:
-Prunus necrotic ringspot virus
-Apple mosaic virus
-Arabis mosaic virus
-Strawberry latent ringspot virus
Symptoms of RMV can include bright yellow banding, yellow netting, unequal leaf margins and leaf distortion, less winter hardiness than virus-free specimens, diminished flower production, reduced plant size and reduced vigor. Strains of viruses differ in their virulence. Infection by some strains is almost symptomless.

All forms of RMV are transmitted by vegetative propagation - - budding, grafting, and cuttings. A few are also transmitted by nematodes.

Sometimes a rose with severe RMV can often be spotted by looking at the leaves (see photo tab). Inspecting the leaves will not tell which virus infects the rose. Most importantly, lack of symptoms does not mean the rose does not have RMV. Testing can detect a number of viral infections of the rose, but tests do not yet exist for every suspected virus. From "Viruses," M.S. Szyndel, Encyclopedia of Rose Science, pp. 180-189.

In the USA, many state agricultural cooperative extension services have excellent online information about RMV with good pictures. One example is the pdf file from New Mexico State University Cooperative Extension which can be
downloaded href="http://aces.nmsu.edu/ces/plantclinic/documents/rmv.pdf" at this link.*
*[unfortunately, this link is no longer available as at Dec 6, 2017]