Submitted to: Encyclopedia of Plant Pathology
Publication Type: Book / Chapter
Publication Acceptance Date: April 28, 2000
Publication Date: N/A
Technical Abstract: Barley yellow dwarf (BYD) is the most economically important virus disease of cereal crops worldwide. It is ubiquitous in distribution and affects all of the major cereal crops including, wheat, oat, barley, and maize. In addition to the cultivated hosts, BYD affects over 150 species of wild grasses in the family Poaceae. The economic impact of the disease varies considerably among crops and geographic regions. Yield loss estimates of 5-10% are common, but severe epidemics can result in significantly higher losses. BYD is caused by a group of related luteoviruses collectively known as barley yellow dwarf virus (BYDV). The 20-28 nm dia. isometric virus particles are found in relatively low amounts only in the phloem tissues. Virus particles are difficult to observe by electron microscopy using leaf dips or thin-sections of plant tissues and are difficult to purify. Yields generally range from 100 ng to 1 mg per kilogram of infected tissue. The viruses are not mechanically or seed transmitted and rely on aphids to carry them between plant hosts.