Occurrence of Maize Dwarf Mosaic Virus on Sorghum in Zambia. R. W. Toler, Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843. Bhola Nath, D. Roose, and G. M. Kaula. Mt. Makulu Central Research Station, P/B7 Chilanga, Zambia. Plant Dis. 73:273. Accepted for publication 17 January 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0273E.
Viruslike symptoms on sorghum (Sorghum bicolor (L.) Moench) cultivar ZSV-I were observed at the Mt. Makulu Central Research Station, Chilanga, Zambia, in 1983. Naturally infected sorghum plants were chlorotic and mottled and had red leaf symptoms typical of maize dwarf mosaic virus (MDMV) infection. Mechanical inoculations with sap from infected plants transmitted the virus to MDMV-A-susceptible sorghum cultivars and johnsongrass (s. halepense (L.) Pers.). Electron microscopy revealed pinwheel inclusions and flexuous rods 735-750 nm long (1). Positive reaction to MDMV-A antiserum and negative reactions to MDMV-B and sugarcane mosaic viruses Hand D in ELISA tests identified the virus as MDMV-A. Since these observations were made, a similar disease has been observed in several countries in southeast Africa. This is the first report of MDMV-A in Zambia.