Characterization of an Isolate of Zucchini Yellow Mosaic Virus form Cucumber in Singapore

AbstractZucchini yellow mosaic virus (ZYMV) was first found in cucumber in Singapore in 1989. This virus was propagated in Cucurbita pepo cv. First Taste and mechanically transmitted to 12 species of six families. It induced milder symptoms than the Connecticut and Florida strains of ZYMV in infected leaves of C. pepo cv. Zucchini Elite. ZYMV‐S is neither seed nor aphid transmissible. Immunoelectron microscopy revealed that ZYMV‐S is distantly related to WMV‐2, Moroccan WMV, and TelMV, but not, related to PRSV or ZYFV. Cytoplasmic pinwheels and scrolls were observed in ultrathin sections of infected leaf cells by light, confocal laser scanning, and transmission electron microscopy. The molecular weights of the viral coat protein and cytoplasmic inclusion protein, RNA and dsRNA were estimated to be 3.2 × 10−1, 6.1 × 104, 3.23 × 106 and 6.53 × 106 daltons, respectively.