Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2008
Publication Date: 7/1/2008
Citation: Adkins, S.T., Webb, S., Baker, C., Kousik, C.S. 2008. Squash vein yellowing virus detection using nested polymerase chain reaction demonstrates Momordica charantia is a reservoir host. Plant Disease. 92:1119-1123. Interpretive Summary: This is the first report of a weed reservoir for Squash vein yellowing virus (SqVYV). A description of the cucurbit weed hosts, symptoms, whitefly transmission and diagnostic methods used to confirm the identity of SqVYV are presented. This report continues a cooperative research effort between USDA-ARS, University of Florida and Florida Department of Agriculture and Consumer Services-Division of Plant Industry, and provides a timely account of SqVYV infection of cucurbit weeds to growers, Extension personnel and state and Federal regulatory and research scientists.
Technical Abstract: Squash vein yellowing virus (SqVYV) is a recently described ipomovirus from cucurbits in Florida that induces the relatively unusual symptoms in watermelon of plant death and fruit rind necrosis and discoloration, commonly known in Florida as watermelon vine decline. In this report, we demonstrate through the use of nested polymerase chain reaction (PCR) that Momordica charantia L. (Balsam-apple), a common cucurbit weed, collected in 2005 and 2007 from within or adjacent to fields of declining watermelon is often infected with SqVYV. We also found that M. charantia located in or around fallow watermelon fields between spring and fall 2007 watermelon crops is also infected with SqVYV, showing that this weed can serve as an oversummering host for this virus. We also show that Melothria pendula L. (creeping cucumber), another common cucurbit weed, can be experimentally infected with SqVYV. We show nested PCR is 10 to 1000 times more sensitive than non-nested PCR for SqVYV detection in several cucurbit hosts including M. charantia and watermelon. We further demonstrate that whiteflies can acquire SqVYV from infected M. charantia and transmit it to watermelon and squash. These results suggest that improved management of M. charantia and other cucurbit weeds needs to be incorporated into an overall watermelon vine decline management plan to reduce sources of SqVYV and other viruses.