Disease Note.

Mycoplasmal Infection Found in Four Ash Species in Midwestern States. W. A. Sinclair, Department of Plant Pathology, Cornell University, Ithaca, NY 14853. P. T. Marshall, and J. Kemperman. Indiana Department of Natural Resources, Vallonia 47281; and Iowa Department of Natural Resources, Elkader 52043. Plant Dis. 71:761. Accepted for publication 22 April 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0761A.

In July 1986. eight sites of ash decline and mortality, in three midwestern states were examined for the presence of the mycoplasmal disease ash yellows, previously associated with ash decline in northeastern states and Ontario (2). The disease was found at every site: three in northeastern Iowa. one in northern Illinoia, and four in northern Indiana. White ash (Fraxinus americana L.) was affected in Iowa, green ash (F. pennsylvanica Marsh. var. lanceolata) in Illinois, and black (F. nigra Marsh.), blue (F. quadrangulata Michx.), green. and white ash in Indiana. Black ash and blue ash are newly recognized hosts. Witches'-brooms were found at each site. The diagnosis of mycoplasmal infection was corroborated for each site and species by nuorescence microscopy using the DNA-binding nuorochrome DAPI (4'6-diamidino-2-phenylindole-2HCI) (1). References: (1) C. Hiruki and A. da Rocha. Can. J . Planl Pathol. 8:185. 1986. (2) J. A. Matteoni mnd W. A. Sinclair. Phytopathology 75:355. 1985.