Occurrence of Welsh Onion Yellows

Abstract

A new disease of Welsh onion, showing the symptoms of stunt, yellows, witches' broom and malformed flower, has occurred in Tokushima and Saitama Prefectures. Electron microscopy revealed the presence of phytoplasma particles in the sieve tubes of diseased plants. Of the two leafhoppers tested, Macrosteles striifrons and Scleroracus flavopictus, only M. striifrons transmitted the disease. The host range of two phytoplasma isolates was similar, and 19 species in 10 families were infected with the two phytoplasma isolates.