Abstract
The tobacco mosaic virus strains, C and W which were isolated from crucifer plants, were compared about their host ranges with those of the other TMV strains, HR, Lychnis strain Ly, two ordinary strains OM and O, cowpea strain BC-B, its tobacco form BC-T, and 06. Strains C and W infected all 18 kinds of crucifer plants systemically, and HR and Ly infected 11 and 15 kinds of them respectively. Sometimes OM infected 5 Brassica plants systemically, but their virus contents were very low. Strains 06, BC-B, and O were inoculated to 6 Brassica plants, but no plants were infected systemically. Strains HR, C, W, and Ly caused only local lesions on the leaves of petunia and most of Nicotiana plants including several tobacco varieties. Among cucurbitaceous plants tested, only M. Charantia showed local lesions by the inoculation of HR, C, W, Ly, and OM. Ph. vulgaris var. Kairyo-Otebo showed no local lesions by the inoculation of HR, C, W, and Ly. Strains HR, C, W, and Ly caused primary lesions on P. lanceolata, and HR and sometimes Ly caused systemic infection. From the similarity of the host ranges and the amino acid compositions of the coat proteins of HR, C, W, and Ly, the authors concluded that these strains should be classified as “HR group” and suggested that TMV strains having a similar native amino acid composition may have a similar host range.
