VIRUS ASSAY OF SEEDS FROM SELECTED MONTMORENCY CHERRY TREES

Abstract

Assays for virus content were made on seed from 40 Montmorency sour cherry trees in an orchard where necrotic ring spot and sour cherry yellows viruses were spreading, the former very rapidly. Virus was detected in 3.5% of the ’sound’ seeds from 10 virus-free trees, in 38.4% from 10 trees with shock symptoms, in 77.7% from 6 trees with sour cherry yellows symptoms, and in 93.1% from 7 trees with necrotic ring spot symptoms. The number of seeds with virus, on otherwise virus-free trees, did not provide a reliable indication of the tendency of a tree to become infected. The average percentage of aborted seeds was: sour cherry yellows infected trees 35%, necrotic ring spot trees 22%, trees in shock 28%, and non-infected trees 15%.