Resistance to blueberry shoestring virus in southern highbush and rabbiteye cultivars

To determine if blueberry shoestring virus (BBSSV) is absent in the southern United States due to resistance of cultivars, we mechanically and rub-inoculated 1-year-old rooted microshoots of nine cultivars representing southern rabbiteye (Vaccinium ashei Reade), southern highbush (hybrids of V. corymbosum and V. darrowi Camp), and northern highbush (V. corymbosum L.). Leaves were sampled from plants, and enzyme-linked immunosorbent assay screened for the presence of virus over 15 months. Only a few individuals were infected after aphid inoculation, but many northern and southern cultivars became infected after mechanical inoculation. Northern highbush 'Elliot' (50%) and 'Blueray' (46.3%) had the highest infection rates, followed by rabbiteye 'Climax' (36.3%) and the southern highbush 'O'Neal' (12.5%). The lowest rates of infection were found in southern highbush 'Georgiagem' (2.5%), 'Misty' (2.5%), rabbiteye 'Brightwell' (0.0%), and northern highbush 'Bluecrop' (2.5%). Since many southern cultivars were infected by the disease, resistance likely has not excluded BBSSV from the southern United States.