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Etiology

Additional Hosts and an Efficient Purification Procedure for Four Viroids. C. L. Niblett, Department of Plant Pathology, Kansas State University, Manhattan 66506; Elizabeth Dickson(2), R. K. Horst(3), and C. P. Romaine(4). (2)Rockefeller University, New York, NY 10021; (3)Department of Plant Pathology, Cornell University, Ithaca, NY 14853; (4)Department of Plant Pathology, The Pennsylvania State University, University Park 16802. Phytopathology 70:610-615. Accepted for publication 23 November 1979. Copyright 1980 The American Phytopathological Society. DOI: 10.1094/Phyto-70-610.

Additional hosts of potato spindle tuber viroid (PSTV), citrus exocortis viroid (CEV), chrysanthemum stunt viroid (CSV), and chrysanthemum chlorotic mottle viroid (ChCMV) are reported. Chrysanthemum morifolium is a new host of PSTV (both mild and severe strains) and CEV. Both viroids reach high concentrations in chrysanthemum. Tomato (Lycopersicon esculentum ‘Rutgers’) and Gynura aurantiaca are new hosts of CSV; and Chrysanthemum zawadskii is a new host of ChCMV. PSTV and CEV were purified from these hosts, labeled in vitro with ¹²⁵I and identified by RNA fingerprinting analysis. Comparisons of fingerprints of these viroids from several hosts confirmed a previous report that the nucleotide sequence of viroid RNA is not determined by the host plant. An efficient purification procedure for PSTV, CEV, and CSV is described. Yields of 10–50 times greater than those of published procedures for PSTV were obtained. Additional evidence for the viroid nature of ChCMV and its symptomless strain were obtained by demonstrating infectivity following fractionation in 5–15% polyacrylamide gels.