Nathan Schnur and Isaac Vohland12/06/2007

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

lossLeft: Isolated virus particles

Recently found in Midwest Illinois and Wisconsin

Only expected to have major impact in localized areas

Harrison, et al. 2005

Four Strains Dwarfing Strain

DS and DP

Yellowing Strain YS and YP

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

Overwinters in perennial clovers Many clovers on ditch banks in Midwest Close proximity to soybean fields

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)

Fox Glove Aphid

Pea Aphid

Disease Cycle Circulative-Persistently

transmitted Retained when aphid

molts Take 10-30mins to

ingest the virus Latency Period of 15-

27h

There are several management practices which are useful to control SbDV. Resistance Vector Control Alternate Host Control

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 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

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

Present in Midwest, but not yet serious problem

This may change if the vectors become more prevalent

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/