Watermelon Mosaic Virus

Watermelon Mosaic Virus (WMV) also known as Marrow mosaic virus (Raychaudhuri and Varma, 1975; Varma, 1988), Melon mosaic virus (Iwaki et al., 1984; Komuro, 1962), and until recently Watermelon mosaic virus type 2 (WMV-2), is a plant pathogenic virus that causes viral infection (sometimes referred to as watermelon Mosaic disease) in many different plants. First described on squash in Florida, WMV arose from a unique recombination of genetic material contributed by Soybean mosaic virus (SMV) and Bean common mosaic virus (BCMV) along with Peanut Stripe virus (PSV). According to Florida State's Department of Plant Pathology and Agronomy, watermelon mosaic virus is a potyvirus whose particles are 760 nm long flexous rods which has a single strand of RNA. This particular genome structure closely relates WMV to other crop viruses such as Zucchini yellow mosaic virus (ZYMV) and Papaya ringspot virus (PRSV). In its hosts, it induces cylindrical inclusions in the cytoplasm which damages the host's tissue. This virus is primarily transmitted non-persistently by many species of aphids and can take most members of the Cucurbitacea family and many leguminous species as hosts. The virus is more common in temperate regions as well as in the tropics though it has been reported in most countries where cucurbits are grown. Recently, WMV has been the cause of severe economic losses to crop yields of cucurbitaceous, leguminous, malvaceous and chenopodiaceous plants in temperate and Mediterranean regions. The virus itself is referred to as Watermelon Mosaic Virus II or WMV-2 and is an isolate of the U.S. WMV-2 is a ssRNA positive strand virus that is part of the Potyviridae or Potyvirus clade. Like all RNA viruses, it contains a protein capsid which protects the inner viral RNA.