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.