Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: August 1, 1996
Publication Date: N/A
Technical Abstract: Viruses cause important diseases in corn (Zea mays L.). Some virus diseases are widespread; others are localized. Yield losses from some maize virus disease may be sporadic and devastating. However, losses from others may occur each year but are relatively minor because highly resistant or tolerant germplasm or good weed control with herbicides are available. Properties of corn viruses vary. They have either a RNA or DNA genome. The RNA is either single- or double-stranded. The particle morphology is either a rod, sphere, or bacilliform. Many corn viruses are transmitted by arthropod vectors. A few are soil-borne. Some corn viruses differentially infect different maize genotypes, others infect, to some degree, all corn genotypes so far tested. The major economical impact of corn virus diseases is loss on grain yield. Virus diseases often are first detected by symptoms. Accuracy in disease identification is increased by a long working experience with the disease, by knowledge of the symptom variations associated with various corn genotypes or various virus isolates, and by awareness of what other pathogens which might coinfect corn in that area. Accurate disease identification is definitely enhanced when symptomatology is augmented with other chemical, biological, and serological assays. Characteristic traits of maize chlorotic dwarf waikaivirus, maize chlorotic mottle sobemovirus, maize dwarf mosaic and wheat streak mosaic potyviruses, maize rayado fino marifivirus, maize mosaic rhabdovirus, maize rough dwarf fijivirus, maize streak geminivirus, maize stripe tenuivirus, and maize white line mosaic virus are described.