Daphne virus Y: A potyvirus from daphne

Abstract Daphne virus Y (DVY) was associated with a severe chlorotic mosaic on Daphne odora Thunb, ‘Leucanthe’, ‘Leucanthe Alba’, and ‘Rubra‘. DVY infected four species of Chenopodiaceae and Nicotiana clevelandii Gray, but did not infect 19 other herbaceous species from 9 plant families. In expressed Chenopodium quinoa Willd. sap, infectivity was lost after 7‐8 days at room temperature; after heating for 10 min at 65°c; or when diluted to 10 ‐5 . Myzus persicae (Sulz.) transmitted DVY in a non‐persistent manner. Preparations of DVY purified by chloroform clarification and differential and sucrose‐gradient centrifugation had a sedimentation coefficient of 149S. The preparations failed to react with antisera to nine different potyviruses in microprecipitin tests. The flexuous, filamentous particles present in negatively stained squash homogenates of DVY‐infected tissue had a normal length of 733 nm. Ultrathin sections of C. quinoa , and of daphne leaves and flowers, contained cylindrical inclusions typical of those induced by other potyviruses. The present cryptogram for DVY is */* : */* : E/E : S/Ap.