First Report of Papaya ringspot virus on Papaya in Iran

Papaya, a popular fruit crop native to the American tropics, was introduced to the southern tropical provinces of Iran in the 1990s and its cultivation is widely increasing in these areas. During April 2000, severe leaf distortion and mottling were observed on papaya trees (Carica papaya) in Hormozgan Province in southern Iran. Affected trees were stunted and yielded less fruit. Samples of papaya leaf extracts (1:10 wt/vol) in 0.01 M potassium phosphate buffer (pH 7.0) were mechanically inoculated on indicator host plants, causing local lesions on Chenopodium amaranticolor and C. quinoa and chlorotic spots followed by systemic mosaic symptoms on Cucurbita pepo. Papaya ringspot virus (PRSV) was detected in the leaf samples of papaya plants and the inoculated Cucurbita pepo plants using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with PRSV-specific antisera (polyclonal antibody AS-0086 and PV-0244, DSMZ, Braunschweig, Germany). PRSV causes one of the most destructive diseases of papaya worldwide (1). PRSV has been previously reported from Citrullus vulgaris and Cucumis melo from Iran as Watermelon mosaic virus 1 (2), but to our knowledge, this is the first report of occurrence of PRSV on papaya in Iran.