ABSTRACT

Brandes and Wetter classified viruses ca. 300 nm long in what is now called the tobamovirus group into their group number 3. Tobamoviruses are transmitted mechanically. Tosic and Tosic reported the isolation of TMV from waters of the rivers Danube, Po, Sacramento, and Sava. Tobamoviruses induce cytoplasmic crystalline inclusions of particles parallel to each other in monolayers, usually in stacks with rounded or hexagonal outlines in end view, and have rectangular or stair-stepped outlines in side view. Cytoplasmic vacuolated granular X-bodies were observed in bean cells. Paracrystals of virus particles were reported in the cytoplasm of sunn hemp and hyacinth bean. The virus particles within the monolayers of the stacked-plate inclusions (hexagonal or rounded) are parallel to each other, with the long axes of the particles perpendicular to the top and bottom planes of the inclusion (Plate 3C,D). The X-body, paracrystalline, and crystalline inclusions stain green in O-G, and the X-body stains red in Azure A.