Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: January 3, 2007
Publication Date: July 5, 2007
Citation: Kousik, C.S., Adkins, S.T., Roberts, P.D. 2007. Potential Sources of Resistance in Watermelon Plant Introductions (PI) to Watermelon Vine Decline in Florida. Phytopathology. 97:S59. Technical Abstract: Watermelon vine decline (WVD) also known as mature watermelon vine decline has been a major limiting factor in watermelon (Citrullus lanatus) production in southwest and west central Florida for the past several years. Symptoms of WVD typically occur at harvest time or one to two weeks prior to harvest. The disease causes sudden decline of the vines and can also affect the fruit quality. Recently, it was determined that a whitefly (Bemisia tabaci)-transmitted ipomovirus (family: Potyviridae) named Squash vein yellowing virus (SqVYV) was the causal agent of this disease. We evaluated 218 plant introductions (PI) belonging to the watermelon core collection for tolerance to SqVYV by mechanical inoculations of the plants in a greenhouse. Several PIs with tolerance to SqVYV were identified in the greenhouse and further screened in the field in Immokalee, FL. Overall, PI 500354 (Citrullus lanatus var. citroides) and PI 386024 (Citrullus colocynthis) were the most tolerant to SqVYV compared with Mickey Lee and Crimson Sweet which were highly susceptible. We also observed variability in the resistant reaction to SqVYV within these PIs. SqVYV was detected using DNA probes in the plants and fruits of the susceptible cultivars but not in the tolerant PI. Further evaluations and selections will be made in the coming seasons to confirm the reactions of these PI to WVD.