Disease Note

Tulip Breaking Virus and Tobacco Rattle Virus Isolated from Infected Tulips in South Africa. V. H. Whitlock, Department of Microbiology, University of the Witwatersrand, Johannesburg, South Africa. Plant Disease 68:351, 1984. Accepted for publication 12 December 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-351a.

Tulip (Tulipa gesneriana L.) plants with leaf mottling and flower break symptoms were found in the Transvaal of South Africa, where tulips have been grown commercially for the past 10 yr. Two different isolates were obtained from the infected plants: flexuous rod particles (750 X 15 nm) and 100-nm rod-shaped particles (some 210 nm long) typical of tobacco rattle virus (TRV). Phaseolus vulgaris L. developed local pinpoint lesions when inoculated with the second type of isolate, and a microprecipitin reaction with TRV antiserum established the identity of the virus. The first type of isolate reacted positively with tulip breaking virus (TBV) antiserum. Flower symptoms were typical of those reported with TBV. Of the 130 plants examined, 44 (34%) were infected with both viruses, 11 (8.5%) were infected with TRV only, and the remainder were infected with TBV only. Neither virus has been reported from South Africa before, and their rate of spread in this country is unknown.