The virus status of raspberries (Rubus idaeus L.) in New Zealand

Abstract

As a result of field observations for virus symptoms, mechanical inoculation to herbaceous test plants, and grafting to Rubus indicators, 6 distinct viruses were identified in red raspberry, and tobacco streak virus was identified in a bramble selection. Cherry leaf roll and raspberry bushy dwarf viruses and raspberry yellows disease were found commonly in all the major raspberry producing regions. Of the aphid-borne viruses, raspberry vein chlorosis was common in some regions, but black raspberry necrosis, raspberry leaf mottle, and raspberry leaf spot viruses were detected in only 7 of 43 plants indexed. The aphid Macrosiphum euphorbiae (Thomas) (a vector of black raspberry necrosis virus) was found colonising raspberry. As the incidence of infection with most of the viruses appears to be due to propagation from infected stock, the virus health status of New Zealand raspberries could readily be improved by ensuring propagation from virus-free material. However, raspberry bushy dwarf virus is spread rapidly by pollination and this virus can be controlled adequately only by growing immune cultivars.