Virus and virus-like diseases of roses in New Zealand : a thesis on studies conducted in the Department of Horticulture and Plant Health in partial fulfilment of the requirement for a Doctor of Philosophy degree at Massey University
Roses in New Zealand were surveyed for the presence of symptoms which might be caused by virus or virus-like graft transmissible agents. Representative samples (221) of all symptom types and many apparently symptomless plants were indexed by a number of methods. Prunus necrotic ringspot virus was found to be widespread, occuring in plants both with and without symptoms. Apple mosaic virus was detected in one plant and arabis mosaic virus was detected in some plants of one cultivar clone. Prune dwarf virus, tobacco streak virus, tobacco ringspot virus, and strawberry latent ringspot virus were not detected. Two graft transmissible virus-like diseases of rose flowers are described. One of them, rose petal fleck, was widespread in both obviously affected and symptomless plants. The other, rose colour break, was largely confined to some glasshouse cutflower cultivars and a few garden cultivars.