|Webb, S. E.|
|Baker, C. A.|
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/24/2006
Publication Date: 2/1/2007
Citation: Adkins, S.T., Webb, S., Achor, D., Roberts, P., Baker, C. 2007. Identification and characterization of a novel whitefly-transmitted member of the family potyviridae isolated from cucurbits in florida. Phytopathology. 97:No. 2, 145-154. Interpretive Summary: This is the first report of a novel virus species, Squash vein yellowing virus (SqVYV) infecting cucurbits in Florida. A description of the symptoms caused and biological and molecular characterization of the virus, including insect transmission and diagnostic methods, are described. This report continues a cooperative research effort between ARS, the University of Florida and the Florida Department of Agriculture and Consumer Services, Division of Plant Industry. It also provides a timely account of this new virus and its role in an ongoing disease (mature watermelon vine decline and fruit rot) to growers, Extension personnel and state and Federal regulatory and research scientists.
Technical Abstract: A novel whitefly-transmitted member of the family Potyviridae was isolated from a squash plant (Cucurbita pepo) with vein yellowing symptoms in Florida. The virus, for which the name Squash vein yellowing virus (SqVYV) is proposed, has flexuous rod-shaped particles of ~840 nm in length. Koch’s postulates were completed by mechanical inoculation of squash and watermelon with isolated virions. The experimental host range was limited to species in the Cucurbitaceae, with most dramatic symptoms in squash and watermelon, but excluded all tested species in the Amaranthaceae, Apocynaceae, Asteraceae, Chenopodiaceae, Fabaceae, Malvaceae and Solanaceae. The virus was transmitted by whiteflies (Bemisia tabaci) but was not transmitted by aphids (Myzus persicae). Infection by SqVYV induced inclusion bodies visible by electron and light microscopy that were characteristic of members of the family Potyviridae. Comparison of the SqVYV coat protein gene and protein sequences with those of recognized members of the family Potyviridae indicate that it is a novel member of the genus Ipomovirus. A limited survey revealed that SqVYV was also present in watermelons suffering from a mature vine decline and fruit rot recently observed in Florida and was sufficient to induce these symptoms in greenhouse-grown watermelons.