Samples of the plants Deschampcia аntarctica and Colobanthus quitensis that were collected in 2007 at Island Yalour, Pitterman, Galindez, cape Rassmunsen and Island Barkhan, Uruguay were analysed. Presence of viral antigens that belong to different taxonomic groups - Cucumovirus, Tobamovirus, Tospovirus in Deschampcia аntarctica and antigens of CGMMV in Colobanthus quitensis using ELISA, bioassay and immunosorbent electron microscopy was estimated.