**2.2 Genus:** *Tobamovirus*

The viruses in the genus *Tobamovirus* are especially important because they do not require biological vectors for transmission. Members of this genus have flexuous filamentous ssRNA particles approximately 300 nm in length and 18 nm in diameter that can persist for years and survive many adverse environmental conditions because of their strong structural coat protein. Due to their high stability, tobamoviruses remain infectious in contaminated plant debris, compost, soil and irrigation water. Viruses in this genus include TMV, ToMV and PMMoV [13].
