OCCURRENCE OF A VEIN-CLEARING TOBAMOVIRUS IN TURNIP

A tobamovirus that infects turnips was identified as a contaminant of a preparation of cauliflower mosaic virus (CaMV). Because the virus caused vein clearing, it was designated turnip vein-clearing virus (TVCV). It was separated from CaMV in the preparation by alternate passage through a CaMV host and a nonhost or by treatment of the viral nucleic acids with DNAse. The purified TVCV contained a single species of single-stranded RNA similar in size to that of tobacco mosaic virus (TMV) and a single species of polypeptide similar in size to, but distinguishable from, the TMV coat polypeptide. Serological tests demonstrated TVCV was related, but not identical, to TMV vulgare. The reaction of several plant species to TVCV differed from the reaction of these plants to known crucifer-infecting tobamoviruses. On the basis of its physical, serological, and biological characteristics, TVCV appears to be a previously unreported tobamovirus.