Skip to main content
ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #306178
Title: Iris yellow spot virus (Tospovirus: Bunyaviridae): from obscurity to research priority

Author
item BAG, SUDEEP - Washington State University
item SCHWARTZ, H - Colorado State University
item CRAMER, C - New Mexico State University
item Havey, Michael
item PAPPU, H - Washington State University

Submitted to: Molecular Plant Pathology
Publication Type: Review Article
Publication Acceptance Date: 7/23/2014
Publication Date: 12/6/2014
Citation: Bag, S., Schwartz, H.F., Cramer, C.S., Havey, M.J., Pappu, H.R. 2014. Iris yellow spot virus (Tospovirus: Bunyaviridae): from obscurity to research priority. Molecular Plant Pathology. 16:27.

Interpretive Summary:

Technical Abstract: Iris yellow spot virus (IYSV) is in the genus Tospovirus, family Bunyaviridae, with a single-stranded negative sense, tri-segmented RNA genome. The other genera in the family infect predominantly vertebrates and insects. IYSV is present in most of the Allium-growing regions in the world. Virions are pleomorphic particles of 80-120nm in size. The particle mainly consists of RNA, protein, glycoprotein and lipids. IYSV shares the genomic features of other tospoviruses: a segmented RNA genome of three RNAs referred to as large (L), medium (M), and small (S). The L RNA codes for the RNA dependent RNA polymerase (RdRp) in its negative sense. The M RNA uses an ambisense coding strategy and codes for the precursor for the GN/GC glycoprotein in the viral complementary (vc) sense and a non-structural protein (NSm) in the viral (v) sense. The S RNA also uses an ambisense coding strategy with the coat protein (N) in vc sense and a non-structural protein (NSs) in the viral sense. The virus is transmitted by Thrips tabaci Lindeman (Order: Thysanoptera; Family: Thripidae; onion thrips), and with less efficiency by Frankliniella fusca Hinds (Tobacco thrips). Host: IYSV has a relatively broad host range, including cultivated and wild onion, garlic, chives leek, and several ornamentals. Some weeds are naturally infected by IYSV and may serve as alternate hosts for the vector and virus. IYSV symptoms in Alliums are yellow to straw-colored, diamond-shaped lesions on leaves and flowering scapes. Diamond-shaped lesions are particularly pronounced on scapes. As the disease progresses, the lesions coalesce leading to lodging of the scapes. In seed crops, this could lead to reducing yield and quality. Early to mid-season infection in bulb crops result in reduced vigor and bulb size. Resistant varieties are not available but a limited number of accessions with field tolerance were identified. Integrated disease management tactics that include sanitation, crop rotation, thrips management, maintaining optimal plant vigor, soil fertility, irrigation and physical separation of bulb and seed crops can mitigate the effect of the disease incidence.