Physiological Effects ofSquash vein yellowing virusInfection on Watermelon

Abstract

Adkins, S., McCollum, T. , W. W. 2013. Physiological effects of Squash vein yellowing virus infection on watermelon. Plant Dis. 97:1137-1148.Squash vein yellowing virus (SqVYV) is the cause of viral watermelon vine decline. The virus is whitefly-transmitted, induces a systemic wilt of watermelon plants, and causes necrosis and discoloration of the fruit rind. In the field, SqVYV is often detected in watermelon in mixed infections with other viruses including the aphid-transmitted Papaya ringspot virus type W (PRSV-W). In this study, watermelon plants of different ages were inoculated with SqVYV or SqVYV+PRSV-W in the greenhouse or SqVYV in the field to characterize the physiological response to infection. Symptoms of vine decline appeared about 12 to 16 days after inoculation with SqVYV regardless of plant age at time of inoculation, plant growth habit (trellised or nontrellised), and loca-tion (greenhouse or field). However, the presence of PRSV-W delayed the appearance of vine decline symptoms by 2 to 4 days, and vine decline did not develop on plants with no fruit. For all inoculation treatments, more severe symptoms were observed in younger watermelon plants. Physiological responses to SqVYV infection included reduction in plant and fruit weights, alterations in fruit rind and flesh color, reduction in fruit sucrose content, increase in fruit acid content, and changes in plant nutrient composition, particularly increases in Ca, Mg, B, Mn, and Zn and decreases in K and N. These results demonstrate wide-ranging physiological effects of SqVYV infection and provide new insights into watermelon vine decline.

Squash vein yellowing virus Infection of Vining Cucurbits and the Vine Decline Response

“…The lack of reported SqVYV detection in Cucurbita maxima may be due to the lack of symptoms in fruits (with no rind necrosis in either greenhouse or field grown plants) and decline symptoms being delayed compared to watermelon. Early infection of young Cucurbita maxima plants could be more serious, as suggested by the decline of young plants in our greenhouse studies, although SqVYV-induced decline of young watermelon plants in commercial fields has not been reported (1). In northern states, cold winters likely limit survival of cucurbit weed or volunteer crop reservoirs for the virus to pass from one growing season to the next.…”

“…To examine the response to SqVYV inoculation of mature plants bearing fruit, 21 vining cucurbits in 12 species were vertically trellised on soft cotton strings to allow production of larger plants with fruit, more typical of field grown plants as described elsewhere (1). Cucurbits were selected to represent crop and weed species, and the diversity of symptoms observed in the initial experiments on young plants without fruit.…”

With or Without You: Altered Plant Response to Boron-Deficiency in Hydroponically Grown Grapevines Infected by Grapevine Pinot Gris Virus Suggests a Relation Between Grapevine Leaf Mottling and Deformation Symptom Occurrence and Boron Plant Availability

“…Little is known about the effects of virus infection on nutrient uptake, distribution and accumulation in plant tissues, although mineral nutrition plays an important role in plant-pathogen interactions (Datnoff et al, 2007;Huber et al, 2012) and in disease control practices (Dordas, 2008;Gupta et al, 2017). Previous work has demonstrated that the presence of virus affected P, Mg, B, Cu, and Mo content in infected leaves (Overholt et al, 2009;Adkins et al, 2013), but the alterations seemed to vary according to the virus considered. In this work, GPGV did not influence the concentrations of B or those of most nutrients.…”

Spatial and Temporal Analysis of Squash vein yellowing virus Infections in Watermelon

“…In addition to watermelon, the virus can infect numerous other cucurbit species, including several common cucurbit weeds, some of which serve as reservoirs for SqVYV (4,5,33). Symptoms vary depending on host but, in watermelon, infection by SqVYV results in a rapid collapse of the plant (hence the name watermelon vine decline) that typically occurs as the crop nears harvest (1).…”