Serological relationships among the virus strains (TMV-T, TMV-OM, CGM MV-W, CGMMV-C, CGMMV-Y) of tobamovirus group were confirmed by passive hemagglutination and reverse passive hemagglutination. Heterologous reactions among the five strains revealed that TMV-OM was more closely related to TMV-T and CGMMV-W than to the other strains but TMV-T and CGMMVW were distantly related and that CGMMV-C and CGMMV-Y were closely related serologically.
A disease of carrot, Daucus carota, which was characterized by the brown rot lesion formed on the taproots, was recorded in 1982 in Aomori Pref., Japan. The causal fungus was identified as Cylindrocarpon obtusisporunt (Cooke & Harkness) Wollenweber, and the fungus could only be able to attack carrot. This is the first report on the fungus from Japan.