Bacterial Wilt Resistance in Blueberry Species

ABSTRACT Blueberry production is expanding rapidly in the United States and globally. In 2016, bacterial wilt was discovered in Florida blueberry production. Because of the international movement of plants, this disease poses a significant risk to production. The purpose of this project was to evaluate the resistance of blueberry species and cultivars to the three genetically distinct populations of Ralstonia identified in Florida blueberry production. Nineteen cultivars/species of Vaccinium were used in this study. Plants were selected from wild, northern, southern, midbush, lowbush, and rabbiteye varieties. Plants were inoculated with three genetically distinct strains of the pathogen, and experiments were replicated three times. Varying levels of quantitative (multigenic) bacterial wilt resistance were observed among varieties tested, with rabbiteye cultivars being the most resistant. These results are similar to bacterial wilt resistance observed in other agronomic crops. We also observed a unique specific qualitative (vertical) resistance in the rabbiteye cultivar ´Ochlockonee’. The pathogen was unable to colonize plant tissue and cause disease on this cultivar. This is the first report of qualitative resistance to Ralstonia solanacearum in blueberry. Both the multigenic and vertical resistance can be incorporated into blueberry breeding programs to mitigate potential losses to bacterial wilt.