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Soybean dwarf virus. Nathan Schnur and Isaac Vohland 12/06/2007. Background. Left: Isolated virus particles. Genus Luteovirus Spherical virus Originated in Southeast Asia and Japan Very significant disease in Japan Severely reduces yield
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Soybean dwarf virus Nathan Schnur and Isaac Vohland 12/06/2007
Background Left: Isolated virus particles • Genus Luteovirus • Spherical virus • Originated in Southeast Asia and Japan • Very significant disease in Japan • Severely reduces yield • If a field is infected it can result in a 80% yield loss
Distribution • Recently found in Midwest • Illinois and Wisconsin • Only expected to have major impact in localized areas
Distribution Harrison, et al. 2005
Host Range and Symptoms • Four Strains • Dwarfing Strain • DS and DP • Yellowing Strain • YS and YP
Host Range and Symptoms • Soybean, Red Clover, White Clover, Sweetclover • Leaf puckering, yellowing, and stunting • Garden Pea • Mild yellowing of older leaves • Green Bean, Common Vetch • Leaf reddening • Beet • Leaf yellowing
Overwintering Overwinters in perennial clovers Many clovers on ditch banks in Midwest Close proximity to soybean fields
Vectors Fox Glove Aphid Pea Aphid • Aphids are only known vectors • Species of aphids responsible for transmission • Strains YS and DS are transmitted by the fox glove aphid (Aulacorthum solani) • Strains YP and DP are transmitted by both the pea aphid (Acyrthosiphon pisum) and clover aphid (Nearctaphis bakeri)
Disease Cycle • Circulative-Persistently transmitted • Retained when aphid molts • Take 10-30mins to ingest the virus • Latency Period of 15-27h
Management • There are several management practices which are useful to control SbDV. • Resistance • Vector Control • Alternate Host Control
Resistance • Resistance • Transgenic resistance to SbDV • Resistance stems from the insertion of the SbDV coat protein into the soybean genome • This insertion caused RNA silencing (RNAi) • Natural Resistance to SbDV • Some natural resistance has been located in germplasm in Japan • It will take some time for any stable resistance to stem from it
Vector Control • Vector control is centered around controlling aphid populations. • Best way to control aphid populations is with use of pesticides. • There are no soybean cultivars which are 100% resistant. • Pesticides • Asana • Warrior
Alternate Host Control • Host Control • Alternate hosts which are of most concern • Red clover, white clover, and yellow sweetclover • Removal of alternate hosts from the immediate vicinity can greatly reduce inoculum. • Do not plant soybeans in close proximity to fields of clover or other legumes
Conclusion • Present in Midwest, but not yet serious problem • This may change if the vectors become more prevalent
References • References • Kojima, M. and Tamada, T. Soybean Dwarf Virus. 1977. http://www.dpvweb.net/ • Tamada, T. Soybean Dwarf Luteovirus. 1980. http://images.fs.uidaho.edu/vide/descr740.htm • Harrison, B., Steinlage, T. A., Domier, L. L., and D’Arcy, C. J. 2005. Incidence of Soybean dwarf virus and identification of potential vectors in Illinois. Plant Dis. 89:28-32. • ICTVdB Management (2006). 00.039.0.01.015. Soybean dwarf virus. In: ICTVdB - The Universal Virus Database, http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/. version 4. Büchen-Osmond, C. (Ed), Columbia University, New York, USA • Yamagishi N, Terauchi H, Honda K, Kanematsu S, Hidaka S (2006). Discrimination of four soybean dwarf virus strains by dot-blot hybridization with specific probes. J Virol Methods 133:219–222 • Photos Courtesy of: • http://www.genome.ou.edu/ • http://www.wildmanstevebrill.com/JPEG'S/Plant%20Web%20Images/YellowSweetCloverFlowers.jpg • http://www.gardenorganic.org.uk/assets/organicweeds/t_repens2.jpg • http://www.netstate.com/states/symb/flowers/images/red_clover2.jpg • http://www.ces.ncsu.edu/plymouth/graphics/ent/soyapslide06/Slide2.JPG • http://www.agri.pref.hokkaido.jp/tokachi/soy/index-e.html • http://www.tolweb.org/tree/ToLimages/Aphid4_mod.250a.jpg • http://www.agric.wa.gov.au/ikmp/images/Aphis_solani2.jpg • http://www.apsnet.org/Education/IllustratedGlossary/PhotosA-D/circulativetransmission.jpg • http://www.illinoiswildflowers.info • http://i.ehow.com • http://www.discoverlife.org/