A new disease of maize and wheat in the high plains

Dent corn, sweet corn, and blue corn showing severe viruslike symptoms were found in Texas, Kansas, Colorado, Idaho, Nebraska, and Utah in 1993 and 1994. The disease can be devastating to susceptible genotypes, and was also found in wheat. Pathogen nucleoproteins from the infected tissue were concentrated by ultracentrifugation and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealing the coat protein of wheat streak mosaic virus (WSMV) and a unique, approximately 32-kDa protein. Extraction of symptomatic tissue and purification by density gradient centrifugation yielded a product with a nearly pure 32-kDa protein but no defined viruslike structure. Neither electron microscopy of leaf dip preparations nor density gradient purification trials consistently revealed particles other than WSMV. An antiserum has been prepared to the 32-kDa antigen. The pathogen, which we have termed the high plains virus, is transmitted by eriophyid mites.