Rose Ring Pattern: A Component of the Rose-Mosaic Complex

Abstract

A previously undescribed disease of roses, named rose ring pattern (RRP), which has symptoms similar to rose mosaic is described. Symptoms include rings, fine line patterns and chlorotic flecking of the leaves, and (in some cases) color-break rings in the petals. Rosa multiflora ''Burr'' is a reliable indicator for RRP. Symptoms on this rootstock include severe stunting, deformity, rugosity and mottling of the leaflets. Infection of most other major rootstocks is usually without symptoms. Graft inoculation of ''Shiro-fugen'' cherry does not cause a necrotic reaction. Attempts to infect other woody and herbaceous plants were not successful. No natural spread has been observed. Lateral buds propagated from RRP-affected plants held at 38.degree. C for 3 wk or longer were free from infection based on index tests. Injections of Virazole at 200 .mu.g/ml resulted in remission of symptoms in new growth. Rose ring pattern has characteristics distinct from other virus or viruslike diseases of roses, but the causal agent, which is readily transmissible by grafting, has not been identified. Diseased plants have been found in other states [besides California, USA]. Control is achieved by using clean propagating material.