SPECIFIC PCR DETECTION AND IDENTIFICATION OF XYLELLA-FASTIDIOSA STRAINS CAUSING CITRUS VARIEGATED CHLOROSIS

By cloning and sequencing specific randomly amplified polymorphic DNA (RAPD) products, we have developed pairs of PCR primers that can be us ed to detect Xylella fastidiosa in general, and X. fastidiosa that cau se citrus variegated chlorosis (CVC) specifically, We also identified a CVC-specific region of the X. fastidiosa genome that contains a 28-n ucleotide insertion, and single base changes that distinguish CVC and grape X. fastidiosa strains. When using RAPD products to develop speci fic PCR primers, we found it most efficient to screen for size differe nces among RAPD products rather than presence/absence of a specific RA PD band.