Incidence and Distribution of Viruses in Blackberry (Rubus sp.) in Alabama.

A survey was conducted in 2007 to determine the incidence and distribution of viruses in commercial blackberry crops in Alabama. Symptomatic and asymptomatic plants in eight major blackberry producing counties were tested for Impatiens necrotic spot virus, Raspberry bushy dwarf virus, Tobacco ringspot virus, and Tomato ringspot virus using enzyme-linked immunosorbent assay. Seventy-nine percent of the blackberry samples were infected. Tomato ringspot virus was detected in 45% of the samples, followed by Impatiens necrotic spot virus (35%), Tobacco ringspot virus (31%), and Raspberry bushy dwarf virus (26%). Each virus was detected in each of the eight counties surveyed and in each of the 14 blackberry cultivars evaluated in this study. Seventy-eight percent of the asymptomatic blackberry samples tested positive for virus infection, an indication that symptom expression is not necessarily a reliable diagnostic method for virus infection of blackberries. [ABSTRACT FROM AUTHOR]