Detection of Turnip Mosaic Virus Isolates Using an Antiserum to Coat Protein Breakdown Products. Kai-Shu Ling, Graduate Research Assistant, Rosario Provvidenti, Professor Emeritus, and Dennis Gonsalves, Professor, Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Ge-neva, N.Y. 14456. Dennis Gonsalves, professor, Depatment of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva, N.Y. 14456. Plant Dis. 79:809-812. Accepted for publication 19 April 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0809.

The identification of four major pathotypes of turnip mosaic virus, TuMV-Cl,-C2,-C3, and -C4, was based on the specific resistance found in Chinese cabbage (Brassica campestris L. subsp. pekinensis) cultivars from China and Japan. Initial tests with an antiserum to TuMV Florida isolate (TuMV-FL) from another source did not detect TuMV-C2 in sodium dodecyl sulfate (SDS)-immunodiffusion and indirect enzyme-linked immunosorbent assay (ELISA). In order to develop an antiserum with a broader spectrum of reaction, purified virus of TuMV-Cl was stored for 1 week, to ensure cleavage of the coat protein, before being used for immunization. Polyclonal antiserum produced to TuMV-Cl reacted with the four TuMV pathotypes and 15 other isolates in SDS-immunodiffusion and double antibody sandwich and indirect ELISA. In Western blot, this antiserum reacted mainly to breakdown products of 29K and 27K of the coat protein; in contrast, antiserum to TuMV-FL reacted primarily to the native coat protein (38K). Broader reactivity of the TuMV-Cl antiserum should make it useful for screening breeding lines and for general diagnosis of TuMV.