VIEW ARTICLE

Disease Detection and Losses

Comparison of Tomato Bioassay and Slab Gel Electrophoresis for Detection of Potato Spindle Tuber Viroid in Potato. G. L. Schumann, Graduate Research Assistant, Department of Plant Pathology, Cornell University, Ithaca, NY 14853; H. D. Thurston(2), R. K. Horst(3), S. O. Kawamoto(4), and G. I. Nemoto(5). (2)(3)(4)(5)Professor, Associate Professor, Research Technician, and Research Support Specialist, respectively, Department of Plant Pathology, Cornell University, Ithaca, NY 14853. Phytopathology 68:1256-1259. Accepted for publication 13 April 1978. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-1256.

Potato plants from a randomly selected set of 146 Cornell University breeding lines were tested for the presence of potato spindle tuber viroid (PSTV) by both polyacrylamide gel electrophoresis and tomato bioassay. The electrophoretic assay was an adaptation of Morris and Smith’s procedure to a slab gel apparatus that permitted testing of 25 samples at once. Results of both tests were in agreement in 123 cases. In 23 cases, results of the original tests were not in agreement. When 20 were tested a second time, results supported the original electrophoretic data in all but one case. Potato plants of four commercial cultivars and 45 breeding lines representing diverse germplasm were inoculated with mild or severe strains of PSTV. The electrophoretic assay accurately detected PSTV in the inoculated plants. Assay for PSTV by gel electrophoresis is more rapid and reliable than the tomato bioassay.