VIEW ARTICLE

A Radial-Immunodiffusion Test for the Simultaneous Diagnosis of Potato Viruses S and X. James F. Shepard, Department of Botany and Microbiology, Montana State University, Bozeman 59715. Phytopathology 60:1669-1671. Accepted for publication 19 June 1970. DOI: 10.1094/Phyto-60-1669.

The single-radial-diffusion procedure was investigated as a possible means of detecting potato virus S (PVS) as well as potato virus X (PVX) in infected plants. PVS and PVX could both be degraded with 30% pyridine. Pyridine-degraded PVS protein was only useful as immunizing antigen, however, for it would not diffuse well through agar gels. The degradation of purified PVS and PVX with 2.5% pyrrolidine, in contrast, resulted in the production of rapidly diffusing antigen in the case of both viruses. Pyrrolidine was found to be similarly effective for the testing of infective leaf saps when PVS-and/or PVX-degraded protein (D-protein) antisera were impregnated in agar gels. Additional studies with numerous strains of PVX indicated that the single-radial-diffusion procedure for the detection of PVX D-protein fragments should not be restricted to the strain used for immunization.