VIEW ARTICLE

Molecular Plant Pathology

Characterization and Detection of the Strawberry Necrotic Shock Isolate of Tobacco Streak Virus. Drake C. Stenger, Graduate research assistant, Department of Plant Pathology, University of California, Berkeley 94720; Ruth H. Mullin, and T. Jack Morris. Staff research associate, and Professor, respectively, Department of Plant Pathology, University of California, Berkeley 94720. Phytopathology 77:1330-1337. Accepted for publication 10 April 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/Phyto-77-1330.

An isolate of tobacco streak virus (TSV) was recovered from Fragaria vesca displaying typical symptoms of necrotic shock (NS). Host reactions, serological relationships, and RNA sequence homologies were compared among TSV-NS and isolates from blackberry (R), bean (RN), tobacco (M), and white clover (WC). The five isolates could be distinguished from each other by the responses of three experimental host species. Serological and Northern hybridization tests established two distantly related subgroups comprised of isolates NS and R in one group and WC, M, and RN in the other. Recombinant plasmids containing complementary DNA sequences derived from TSV-NS RNA 3 were used to ascertain the suitability of dot hybridization tests for detection of TSV-NS infection in Fragaria spp. Cloned DNA sequences were labeled with ³²P by nick translation and hybridized to nucleic acid extracts spotted onto nitrocellulose. The dot hybridization assay readily detected TSV-NS in extracts representing both acute and chronic infections of Fragaria spp., and the sensitivity of the assay was equivalent to that of double antibody sandwich enzyme-linked immunosorbent assay.