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Etiology

Helium Virus S and Y–Two New Viruses from Commercially Grown Helenium Hybrids. G. H. Kuschki, Universität Gilan, P.O. Box 451, Rasht, Iran; R. Koenig(2), D. Düvel(3), and H. Kühne(4). (2)Institut für Viruskrankheiten der Pflanzen, Biologische Bundesanstalt, Messeweg 11, D3300 Braunschweig, W. Germany; (3)(4)Institut für Angewandte Botanik, Universität Hamburg, Marseiller Str. 7, D 2000 Hamburg, W. Germany. Phytopathology 68:1407-1411. Accepted for publication 14 April 1978. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-1407.

A carlavirus and a potyvirus were isolated from commercially grown Helenium amarum hybrids showing typical symptoms of virus infection. The carlavirus, for which the name Helenium virus S (HelVS) is proposed, has slightly curved particles with a normal length of 640 nm and a sedimentation coefficient of 160 S. Its UV-absorption spectrum has a maximum at 255 nm and a minimum at 238 nm. The ratio of A_max/A_min is approximately 1.2. In sap from infected Chenopodium quinoa HelVS has a thermal inactivation point of 60 to 65 C and an infectivity dilution endpoint of 10^–4 to 10^–5. In the cytoplasm of infected cells typical aggregates of virus particles were arranged in parallel and accumulations of endoplasmic reticulum together with ribosomes and scattered virus particles were found. Serologically, HelVS is related to carnation latent, chrysanthemum B, and potato M viruses. The molecular weight of its protein subunit is 31,000. The potyvirus, for which the name Helenium virus Y (HelVY) is proposed, has flexuous particles with a normal length of 721 nm. In sap from C. quinoa it has a thermal inactivation point of 55 to 60 C and an infectivity dilution endpoint of 10^–4. Helenium virus Y induces typical pinwheels, bundles, and laminate inclusions. Serologically, it shows some relationship with bean yellow mosaic, lettuce mosaic, and potato Y viruses.