Parsnip mosaic virus, a new member of the potato virus Y group

Parsnip mosaic virus (PMV) occurs commonly in parsnip in Britain and is transmitted after acquisition access periods of 2-5 min by the aphids Cavariella aegopodii, C. theobaldi and Myzus persicae. It was transmitted by manual inoculation of sap, infecting parsnip, chervil, coriander and carrot plants systemically, and causing local lesions without subsequent systemic infection in eight Chenopodium spp., Spinacia oleracea, Gomphrena globosa, and Torenia fournieri. It lost infectivity in Chenopodium quinoa sap after dilution to 10(-3)-10(-4) heating for 10 min at 55-58 degrees C or storage at room temperature for 7-10 days. Preparations partially purified by n-butanol or chloroform clarification, followed by acid precipitation and/or chromatography on columns of 2% agarose beads, contained filamentous particles, many of which were aggregated or fragmented. Preparations made with chloroform and without acid precipitation contained unaggregated particles of 755 nm normal length, with a sedimentation coefficient of 149 S. PMV did not react with antisera to any of fourteen other viruses with filamentous particles. The present cryptogram for PMV is */*:*/*:E/E:S/Ap.