A POTYVIRUS CAUSING MOSAIC DISEASE OF SESAME (SESAMUM-INDICUM)

A virus causing chlorosis of veins, mosaic, green banding along veins, and downward leaf rolling in sesame (Sesamum indicum) was isolated from sesame plants grown from seed imported from the Sudan. The virus was sap-transmissible to species of Amaranthaceae, Chenopodiaceae, Cucurbitaceae, Leguminosae, and Solanaceae. Chenopodium amaranticolor was used as a local lesion assay host and Pisum sativum cv. Little Marvel, as the propagation host for purification. The virus was nonpersistently transmitted by Aphis craccivora and Myzus persicae but was not transmitted through the seed of sesame. The virus remained infective in buffered leaf sap of Nicotiana benthamiana at a dilution of 10(-5) after storage for 9 days at 25 C and heating for 10 min to 55 C (but not to 60 C). The virus induced cylindrical cytoplasmic inclusions in infected tissues of Lupinus albus. Purified virus preparations yielded flexuous filamentous particles that contained a major polypeptide of approximately 33 kDa and one nucleic acid species with molecular weight of 3.1 X 10(6). In indirect enzyme-linked immunosorbent assay, the virus reacted positively to antisera of blackeye cowpea mosaic, peanut green mosaic, peanut stripe, pea seedborne mosaic, soybean mosaic, tobacco etch, watermelon mosaic virus 2, and zucchini yellow mosaic viruses but not to watermelon mosaic virus 1 and peanut mottle and bean common mosaic viruses. In reciprocal tests, peanut stripe virus and watermelon mosaic virus 2, but not peanut green mosaic, peanut mottle, pea seedborne mosaic, blackeye cowpea mosaic, soybean mosaic, and tobacco etch viruses, reacted with the antiserum for the sesame virus. On the basis of these properties, the causal virus is identified as an unnamed potyvirus isolate causing sesame mosaic.