Occurrence of Maize Dwarf Mosaic Virus on Maize and Sudangrass in India. G. P. Rao, Division of Plant Pathology, Sugarcane Research Station, Kunraghat - 273008, Gorakhpur, UP, India . R. K. Jain and A. Varma, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi - 110012, India. Plant Dis. 80:711. Accepted for publication 9 April 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-0711B.

During 1993, distinct viruslike symptoms such as mosaic and stunting were observed on maize (Zea mays L.) and sudangrass {Sorghum su-danense (Piper) Stapf) on research farm of sugarcane research station, Gorakhpur, UP. Initial electronmicroscopy of leaf-dip preparations revealed the association of flexuous potyvirus-like particles with symptomatic maize and sudangrass samples. The identity of virus(es) was established by differential hosts reactions and serological assays. Both potyvirus isolates from maize and sudangrass in sap inoculation did not infect oats, eliminating the possibility of johnsongrass mosaic virus (JGMV). The virus isolates gave no reaction to JGMV (D. D. Shukla, CSIRO, Parkville, Australia), sorghum mosaic (SrMV, A. G. Gillaspie, USDA, Griffin, GA) and sugarcane mosaic (SCMV, A. G. Gillaspie) virus antisera but reacted strongly to maize dwarf mosaic virus (MDMV-A, M. Tosic, University of Belgrade, Yugoslavia) antiserum in western blots. The results indicated potyvirus isolates from maize and sudangrass as MDMV isolates. This was further confirmed by immunosorbent electronmicroscopy decoration test. There have been previous reports from India of mosaic disease of maize and sugarcane (1,2). Although the virus was identified as SCMV, there has been confusion as to the virus taxonomy of SCMV and MDMV. For India, this is the first authenticated confirmation of natural occurrence of MDMV on maize and sudangrass