Viruses infecting hop, Humulus lupulus, in Australia

Abstract

In 1981 a survey of the main commercial hop cultivar in Australia, Pride of Ringwood, showed that foliar symptoms were associated with the presence of carlavirus particles. The incidence of plants containing particles varied between fields from 0 to 58%. In 1982 a survey based on enzyme-linked immunosorbent assay showed that the carlaviruses were hop mosaic and hop latent viruses and that they infected 1-68% and 1-58% of plants respectively. Prunus necrotic ringspot virus infected 4-9% of plants. Arabis mosaic virus was detected in a cultivar of English origin and American hop latent virus in cultivars of recent American origin, but neither of these viruses was detected in Australian-bred hops. Virus-free plants suitable for propagation were located in cultivars Pride of Ringwood and B23, and were produced by heat treatment and meristem culture of cultivar Southern Cross.