Identification of viruses isolated from plum trees affected by decline, line‐pattern and ringspot diseases

Abstract

SUMMARY Viruses obtained from plum trees infected with either decline, line‐pattern or ringspot diseases were characterized and identified. All the viruses were serologically related to Prunus necrotic ringspot virus (NRSV); those from trees with decline or ringspot were serologically indistinguishable from cherry strains of NRSV but differed in pathogenicity, whereas the virus from trees with line pattern was closely related to apple mosaic virus. When returned from herbaceous hosts to Prunus , line‐pattern and ringspot isolates reproduced symptoms characteristic of the diseased sources. One virus isolate from trees with decline diminished the vigour of young plum trees. Comparison with other investigations shows that at least two unrelated viruses cause plum line‐pattern disease in America and Europe.