Relationships among some ilarviruses: proposed revision of subgroup A.
Two asparagus virus II strs. (P and S) and 1 isolate each of citrus leaf rugose virus, citrus variegation virus, elm mottle virus and Tulare apple mosaic virus were serologically related in tests with 11 antisera prepared against them. Only 3 of the antisera could detect all 5 viruses in either ring interface or agar gel double diffusion tests. None was serologically related to a group of 4 isolates comprising 2 serotypes of tobacco streak virus. The 5 related viruses exhibited UV absorption max. and min. at 252 and 245 nm respectively, with A260/280 values consistently lower than that of TSV. The results suggest that the 5 viruses differ sufficiently from TSV to justify restructuring the subgroups. A revision of subgroup A is proposed, based on these properties.