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 fr om sesame plants grown from seed imported from the Sudan. The virus wa s sap-transmissible to species of Amaranthaceae, Chenopodiaceae, Cucur bitaceae, Leguminosae, and Solanaceae. Chenopodium amaranticolor was u sed as a local lesion assay host and Pisum sativum cv. Little Marvel, as the propagation host for purification. The virus was nonpersistentl y transmitted by Aphis craccivora and Myzus persicae but was not trans mitted through the seed of sesame. The virus remained infective in buf fered 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 infecte d tissues of Lupinus albus. Purified virus preparations yielded flexuo us filamentous particles that contained a major polypeptide of approxi mately 33 kDa and one nucleic acid species with molecular weight of 3. 1 X 10(6). In indirect enzyme-linked immunosorbent assay, the virus re acted positively to antisera of blackeye cowpea mosaic, peanut green m osaic, peanut stripe, pea seedborne mosaic, soybean mosaic, tobacco et ch, watermelon mosaic virus 2, and zucchini yellow mosaic viruses but not to watermelon mosaic virus 1 and peanut mottle and bean common mos aic viruses. In reciprocal tests, peanut stripe virus and watermelon m osaic virus 2, but not peanut green mosaic, peanut mottle, pea seedbor ne mosaic, blackeye cowpea mosaic, soybean mosaic, and tobacco etch vi ruses, reacted with the antiserum for the sesame virus. On the basis o f these properties, the causal virus is identified as an unnamed potyv irus isolate causing sesame mosaic.