SQUASH YELLOW LEAF CURL VIRUS - A NEW WHITEFLY-TRANSMITTED POTY-LIKE VIRUS

A severe yellow and leaf curl disease affecting field squash was found in the Batinah region of the Sultanate of Oman. The symptoms appear a s small yellow spots, diffuse veinal yellowing, and leaf curling of yo ung leaves. The inciting virus was easily transmitted by mechanical in oculation and by the whitefly Bemisia tabaci in a semi-persistent mann er. The host range of the virus was restricted to two cucurbit species . Leaf dip preparations contained few flexuous particles about 700 to 750 nm long. Pinwheel-like inclusion bodies were observed in thin sect ions of diseased squash tissues. Serological tests by enzyme-linked im munosorbent assay showed that the virus is serologically related to wa termelon mosaic virus-2, but not to zucchini yellow mosaic virus or pa paya ring spot virus (watermelon strain). In view of these properties, this virus is considered to be a newly described virus and is tentati vely named squash yellow leaf curl virus.