ABSTRACT
The tobravirus group has its origins in Brandes and Wetter's group 2 of their classification of elongated plant viruses. Tobraviruses are nematode transmitted, with viruses persisting but not replicating in the vectors. There is insufficient cytological information on inclusions induced by pea early browning and tobacco rattle viruses to allow decisions on their usefulness in diagnosis. Tobravirus staining reactions differ from those of tobamoviruses; particle aggregate, crystalline, and paracrystalline inclusions induced by tobamoviruses require heat to become stained by Azure A; tobravirus-induced inclusions do not. Cytoplasmic inclusions of aggregated Tobacco Rattle Virus particles have been reported in soybean. TRV particles have been observed in small monolayers and aligned on one side of mitochondria with their long axes perpendicular to the mitochondria surface.
