The identification of mild and severe strains of tobacco mosaic virus in doubly inoculated tomato plants.

Using specific antisera, it was possible to identify mild (MII-I6) and the O and I strains of tobacco mosaic virus (TMV) in tomato plants infected with the mild strain following challenge inoculation with the wild strains. In addition, with single lesion isolates of the MII-I6 and O strains it has been shown that both strains can be assayed simultaneously in mixed isolates on Nicotiana glutinisa based on differences in local lesion size. The accuracy of this differential local lesion assay was c. 90% as determined by back inoculation of single lesion isolates into susceptible tomato cultivars.