Submitted to: American Phytopathological Society
Publication Type: Abstract only
Publication Acceptance Date: 3/20/2009
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Blueberry scorch virus (BlScV) is one of the most pervasive pathogens of highbush blueberry. BlScV exhibits a latent period between infection and symptom expression that may extend to years. The virus is vectored by aphids and typically spreads in clustered patterns. However, we have observed BlScV symptom expression that is randomly distributed in young fields and this is inconsistent with an insect vectored introduction. It was therefore speculated that the virus originated from pre-infected nursery stock. To examine this possibility, a survey was conducted of commercial nurseries to test for infected mother plants. Mother plants are pruned so that they do not flower and therefore do not express symptoms. Cuttings of the cultivar Duke were collected from infected and non-infected mother plants and rooted in propagation beds. The survival and infection of cohorts of cuttings from different mother plants was determined one year after planting. A greater proportion of cuttings survived from uninfected mother plants (71%) than from infected mother plants (47%). The resulting plants were tested for BlScV and only cuttings originating from infected mother plants tested positive. Of the cohort propagated from infected mother plants approximately 42% tested positive. This study identifies infected nursery stock as an important source of BlScV spread and underscores the importance of having mother plants routinely virus tested.