ARS | Publication request: Whole genome evaluation of tandem repeat polymorphisms between two pathogenically similar strains of Xylella fastidiosa isolated from almond and grape in California

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 7, 2010
Publication Date: August 7, 2010
Citation: Chen, J., Civerolo, E.L. 2010. Whole genome evaluation of tandem repeat polymorphisms between two pathogenically similar strains of Xylella fastidiosa isolated from almond and grape in California. Phytopathology. 100:S24.

Technical Abstract: Whole genome tandem repeat polymorphisms were evaluated between two closely related Xylella fastidiosa strains, M23 and Temecula1, both cause almond leaf scorch disease (ALSD) and grape Pierce’s disease (PD) in California. Strain M23 was isolated from almond and the genome was sequenced in this study. Strain Temecula1 was originally isolated from grape and its genome was sequenced previously. Among the 48 identified tandem repeat (TR) loci evaluated by sequence similarity flanking the TRs, two were unique to strain M23, six were unique to strain Temecula1, and 40 were shared by both bacterial strains with a similarity of >70%. Yet, the two strains differ in TR numbers (TRNs) in all shared loci. Eight shared loci were selected to evaluate TRN variation using additional 10 X. fastidiosa strains. Results from our analyses indicate that TRN comparison could be highly powerful for discriminating closely related bacterial strains. However, careful selection and evaluation of TR loci is critical in order to avoid over estimating of bacterial strain genetic diversity.