Squash mosaic virus

{{Short description|Species of virus}}

{{virusbox

| name = Squash mosaic virus

| image = Squash mosaic virus Leaves.jpg

| image_caption = Effect of squash mosaic virus on squash leaves

| parent = Comovirus

| species = Comovirus cucurbitae

}}

Squash mosaic virus (SqMV) is a mosaic virus disease common in squash plants and other plants, including melons, of the family Cucurbitaceae.{{cite web|title=Virus Diseases of Cucurbit Crops|url=http://www.agric.wa.gov.au/objtwr/imported_assets/content/hort/veg/pw/fn2006_viruscucurbits_bcoutts.pdf|publisher=Department of Agriculture, Government of Western Australia|accessdate=October 26, 2013}} It occurs worldwide. It is transmitted primarily by beetles, including the leaf beetle (Acalymma trivittata), spotted cucumber beetle (Diabrotica undecimpunctata),{{cite journal|last=Freitag|first=J. H.|title=Beetle Transmission, Host Range, and Properties of Squash Mosaic Virus|url=http://www.cabdirect.org/abstracts/19580500026.html|journal=Phytopathology|volume=46|issue=2|year=1956|pages=73–81|issn=0031-949X}}{{cite journal|last1=Brown|first1=James E.|last2=Dangler|first2=James M.|last3=Woods|first3=Floyd M.|last4=Tilt|first4=Ken M.|last5=Henshaw|first5=Michael D.|last6=Griffey|first6=Wallace A.|last7=West|first7=Mark S.|title=Delay in Mosaic Virus Onset and Aphid Vector Reduction in Summer Squash Grown on Reflective Mulches|journal=HortScience|url=http://hortsci.ashspublications.org/content/28/9/895.full.pdf+html|format=PDF|volume=28|issue=9|date=September 1993|pages=865–896|doi=10.21273/HORTSCI.28.9.895|issn=2327-9834|doi-access=free}} and 28-spotted ladybird beetle (Henosepilachna vigintioctopunctata), as well as some other beetles.{{cite web|title=Mosaic Diseases of Cucurbits|url=http://web.aces.uiuc.edu/vista/pdf_pubs/926.pdf|publisher=University of Illinois|accessdate=October 26, 2013}} Plants are infected by the saliva expelled by the beetles as they feed upon the plant. The beetles acquire the virus by feeding upon an infected plant and can retain the virus in their bodies for up to 20 days.{{cite web|title=Squash Mosaic Virus|url=http://www.ipm.ucdavis.edu/PMG/r116101911.html|publisher=Agriculture and Natural Resources, University of California-Davis|accessdate=October 27, 2013}} Unlike some other mosaic viruses that infect squashes, SqMV is not spread by aphids. In melons it can be spread by seeds. The results are dark green mosaic, blistering, vein clearing, yellowing of leaves, and hardening. Symptoms include "pronounced chlorotic mottle, green veinbanding, and distortion of leaves".{{cite web|title=Virus Diseases of Cucurbits |url=http://vegetablemdonline.ppath.cornell.edu/factsheets/Viruses_Cucurbits.htm|publisher=Cornell University|date=October 1984|accessdate=October 26, 2013}} Fruits of infected plants are also affected, becoming mottled and misshaped. There are two strains of this virus: strain 1 has a greater effect on melons than squash while the opposite is true of strain 2.{{cite web|title=Squash Mosaic Virus (SqMV)|url=http://www.pestid.msu.edu/PlantDiseases/SquashMosaicVirus/tabid/291/Default.aspx|publisher=Michigan State University|accessdate=October 26, 2013}}{{cite journal|last1=Haudenshield|first1=James S.|last2=Palukaitis|first2=Peter|title=Diversity Among Isolates of Squash Mosaic Virus|url=http://vir.sgmjournals.org/content/79/10/2331.full.pdf|journal=Journal of General Virology|volume=79|year=1998|issue=10|pages=2331–2341|pmid=9780037|citeseerx=10.1.1.494.1860|doi=10.1099/0022-1317-79-10-2331}}

SqMV affects all cucurbits (family Cucurbitaceae) and some genera of Hydrophyllaceae, Leguminosae, and Umbelliferae,{{cite journal|last1=Nelson|first1=Merritt R.|last2=Knuhtsen|first2=Hjalmar K.|title=Squash Mosaic Virus Variability: Review and Serological Comparison of Six Biotypes|journal=Phytopathology|volume=63|date=July 1973|issue=7|pages=920–926|url=http://www.apsnet.org/publications/phytopathology/backissues/Documents/1973Articles/Phyto63n07_920.pdf|doi=10.1094/phyto-63-920}} except that most isolates do not affect watermelons. SqMV and cucumber mosaic virus (CMV) are the most common viruses among cucurbits, with CMV being the more common of the two.{{cite web|title=Squash|url=http://aggie-horticulture.tamu.edu/archives/parsons/vegetables/squash.html|publisher=Texas A&M University|accessdate=October 26, 2013}}{{cite journal | last1 = Salama | first1 = El-Sayed A. | last2 = Sill | first2 = W. H. Jr.| year = 1968 | title = Resistance to Kansas Squash Mosaic Virus Strains Among Cucurbita Species | journal = Transactions of the Kansas Academy of Science | volume = 71 | issue = 1 | pages = 62–68 | jstor = 3627399 | doi=10.2307/3627399}} Kendrick is credited with discovering SqMV in 1934, though McClintock may have discovered it in 1916 when he described a highly similar virus, calling it "cucumber virus".