Detection of a potyvirus related to guineagrass mosaic virus infecting Brachiaria spp. in South America

A filamentous virus approximately 775 nm long was isolated from variegated plants of the tropical forage grass Brachiaria spp. collected in Colombia and Brazil, South America. Ultrathin sections of symptomatic leaf tissue showed cylindrical inclusions (scrolls) in the cytoplasm of infected cells. The virus was transmitted mechanically to selected species of Brachiaria, Panicum, and Paspalum but not to maize, sorghum, or sugarcane. The virus was also transmitted from and to B. brizantha by the aphid Myzus persicae in a nonpersistent manner. The virus was not seedborne in Brachiaria spp