Disease Note

Transmission of Tobacco Mosaic and Tobacco Ringspot Viruses from Moraine Ash in New York. L. A. Amico, Department of Environmental and Forest Biology, State University of New York, Syracuse 13210. M. T. O’Shea, and J. D. Castello, Department of Environmental and Forest Biology, State University of New York, Syracuse 13210, and C. R. Hibben, Brooklyn Botanic Garden Research Center, Ossining, NY 10562. Plant Dis. 69:542. Accepted for publication 18 March 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-542c.

Within the past 15 yr, Moraine ash (Fraxinus holotricha Koehne var. Moraine), an ornamental tree grafted onto white ash (F. americana L.) or green ash (F. pennsylvanica Marsh.) rootstock, has shown extensive dieback symptoms in Syracuse and Rochester, New York. Because foliage symptoms included chlorosis, mosaic, and puckering, a virus infection was suspected. Tobacco mosaic virus was mechanically transmitted to tobacco from five of 24 symptomatic trees and two of 10 symptomless trees, and tobacco ringspot virus was transmitted to cowpea from five different symptomatic trees. The viruses were identified by reactions to specific antisera and by symptom expression in herbaceous plants. We speculate the virus source was infected white ash rootstock.