Genotyping Xylella fastidiosa in Rabbiteye blueberry in Louisiana, USA
Rabbiteye blueberry (Vaccinium ashei = V. virgatum) comprises much of the blueberry acreage in the southeastern USA states of Louisiana and Mississippi. Three genotypes of X. fastidiosa were identified from rabbiteye blueberry in Louisiana by multilocus sequence typing. A genotype that was found at two orchards, sequence type (ST) 42, was identical to one previously found in southern highbush blueberry in Georgia and two non-blueberry native species in Texas. Two newly identified genotypes shared most alleles with X. fastidiosa strains considered, like ST 42, to be part of a group that is believed to have resulted from recombination between X. fastidiosa subsp. multiplex and subsp. fastidiosa. These two genotypes each also had one newly identified allele. This work suggests that a narrow range of X. fastidiosa genotypes infect rabbiteye blueberry in Louisiana but that rabbiteye blueberry may serve as an alternative host for X. fastidiosa strains that infect more susceptible southern highbush cultivars.