The partial characterization of melon vein‐banding mosaic virus, a newly recognized virus infecting cucurbits in Taiwan

Abstract

A potyvirus (designated as no. 656) causing mosaic or vein-banding symptoms on melons was isolated and characterized. The virus was mechanically transmitted to 14 herbaceous plant species, and induced mosaic symptoms in most cucurbitaceous plants. Aphis gossypii transmitted the virus non-persistently, and flexuous filamentous virus particles c. 755 nm in length were consistently observed in extracts of the infected pumpkin leaf tissues. Pinwheel and tubular inclusions were observed in the cytoplasm of infected zucchini leaf tissues. The virus was purified from infected pumpkin leaves by isopycnic centrifugation (CS2SO4). The molecular weights of purified capsid and cylindrical inclusion proteins as estimated by SDS-PAGE were 32-5 and 73 KDa, respectively. In SDS-immunodiffusion tests, antiserum to virus particles from isolate 656 was serologically unrelated to ZYMV, WMV-2, PRV-W and a type W variant of PRV, but antiserum to its cylindrical inclusion protein did produce spur precipitin bands between homologous and WMV-2 antigen wells. However, neither WMV-2 virus particle nor cylindrical inclusion antisera reacted with this virus. Furthermore, this virus was not serologically related to BCMV, BYMV, CYVV, SMV, WMV-M or ZYFV. Based on test results and symptomatology, this virus appears to be a new potyvirus, for which the name melon vein-banding mosaic virus (MVbMV) is proposed.