Characterization of an isolate of pepper mild mottle tobamovirus occurring in Canada

A tobamovirus was isolated from tobacco mosaic virus (TMV)-resistant Hungarian cultivars of sweet pepper (Capsicum annuum) in commercial pepper production fields at Richmond, BC, and shown to be a strain of pepper mild mottle virus (PMMV) on the basis of experimental host range, serology, morphology, and cDNA-RNA hybridization. The type strain of PMMV and the very similar Samsun latent strain of TMV (SLV) appeared to be more similar to each other genomically than to the Canadian isolate. Several tobamoviruses were isolated from buffer-washes of seed furnished by growers in Richmond and Oliver, BC, but PMMV was isolated only from Richmond samples, suggesting that the occurrence of the disease in Canada was a consequence of planting infected or contaminated seed.