Resistance of some Australian inbred maize lines to maize dwarf mosaic disease

Abstract

Seven out of eight maize inbred lines developed at Lawes in Queensland from open-pollinated varieties were resistant to maize dwarf mosaic disease when exposed to natural infection in the field. Five of the seven resistant inbred lines failed to become systemically infected when inoculated with infectious sap in the glasshouse. By contrast, only three out of twenty lines introduced from the U.S.A., and two out of eight lines developed at the Grafton and Glen Innes Breeding Stations in New South Wales, were resistant in the field. All three resistant lines from the U.S.A. were systemically infected when inoculated in the glasshouse, but the two resistant lines from Grafton in New South Wales were not. The resistant Lawes and Grafton maize inbred lines would appear to be better sources of genes conferring resistance to maize dwarf mosaic disease than the other lines tested.