Whitefly-transmitted Viruses in Cucurbit Crops

Survey of Whitefly-transmitted Viruses in Watermelon and Other Cucurbit Crops in Alabama, Louisiana, and Mississippi

Photo: Chlorosis on leaves near the crown is visible down the center of rows in a melon field in California with plants infected with both cucurbit chlorotic yellows virus and cucurbit yellow stunting disorder virus. Credit: W. M. Wintermantel, USDA-ARS.

Project Summary: A number of whitefly-transmitted viruses, including cucurbit leaf crumple virus (CuLCrV), cucurbit yellow stunting disorder virus (CYSDV), cucurbit chlorotic yellows virus (CCYV), and squash vein yellowing virus (SqVYV), are able to infect and cause losses in melons and other cucurbit crops. These and other insect-transmitted viruses, which cause similar yellowing symptoms, are known to occur in the larger melon- and watermelon-producing states. Appropriately, research on these viruses has been largely focused on those states. However, natural and manmade activities may lead not only to the introduction of viruses to new areas but also to the expansion of the current georgraphic range of viruses. This is evidenced by the recent spread of cucurbit viruses between California and Florida and from Florida into Georgia and South Carolina. The threat these viruses pose to melon and watermelon production extends to watermelon production in all watermelon-producing states, and the current status of these viruses in states that have not been the focus of research is deserving of exploration, particularly for the benefit of watermelon and other cucurbit producers. The purpose of this project was to determine the occurrence of the major whitefly-transmitted viruses known to infect cucurbits in the Central Gulf Coast states of Alabama, Louisiana, and Mississippi and to educate watermelon and other cucurbit growers and stakeholders on the importance, recognition, and management of these viruses. This was accomplished through a collaborative effort between plant pathologists at the USDA-ARS, Auburn University, Louisiana State University, and Mississippi State University. Samples of watermelon and other cucurbit crops collected during field surveys conducted in Alabama, Louisiana, and Mississippi from 2020 to 2022 were tested for the presence of the known whitefly-transmitted viruses affecting watermelon and other cucurbits in the U.S. Viruses were identified using established molecular detection systems involving multiplex RT-PCR and PCR to amplify specific nucleic acid sequences unique to each virus and gel electrophoresis to visualize amplified products, which allows for the identification and differentiation of the target viruses present in a sample. Project collaborators developed educational resources (linked below) and held an online training (video below) to educate watermelon growers and stakeholders on the known whitefly-transmitted viruses affecting watermelon and other cucurbits in the U.S. Data from the survey is currently being analyzed.

Training Video/Presentation:

Factsheet: Whitefly-transmitted and Yellowing Viruses in Watermelon and Other Cucurbit Crops

Photo Guide: A Photo Guide to Whitefly-transmitted and Yellowing Viruses in Watermelon and Other Cucurbit Crops

Project Collaborators:

• Dr. Rebecca A. Melanson (State Project Leader - Mississippi)

Mississippi State University Extension Service

rebecca.melanson@msstate.edu

(601) 857-2284

• Dr. Edward Sikora (State Project Lead - Alabama)

Alabama Cooperative Extension System - Auburn University

sikorej@aces.edu

(334) 332-7433

• Dr. Rajghuwinder (Raj) Singh (State Project Lead - Louisiana)

Louisiana State University Agricultural Center

RSingh@agcenter.lsu.edu

(225) 578-4562

• ​Dr. William M. Wintermantel (Project Leader)

USDA-ARS

bill.wintermantel@usda.gov

Acknowledgement: This project was funded by the National Watermelon Association. Any opinions or recommendations expressed on this webpage do not necessarily reflect the views of the National Watermelon Association.