ARS | Publication request: SIMULTANEOUS ASSOCIATION OF TWO XYLELLA FASTIDIOSA GENOTYPES WITH ALMOND LEAF SCORCH DISEASE IN CALIFORNIA

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 8, 2004
Publication Date: July 31, 2004
Citation: Chen, J., Groves, R.L., Civerolo, E.L., Viveros, M., Freeman, M., Zheng, Y. 2004. Simultaneous association of two Xylella fastidiosa genotypes with almond leaf scorch disease in California [Abstract]. Phytopathology. 94:S17.

Technical Abstract: Almond leaf scorch disease (ALSD) has recently reemerged in San Joaquin Valley of California threatening almond production. ALSD is caused by Xylella fastidiosa, a nutritionally fastidious bacterium. To analyze the bacterial population, we identified single nucleotide polymorphisms in the 16S rRNA gene from X. fastidiosa genome sequence database and used the information to design primers for multiplex PCR assays. These muliplex PCR assays simultaneously detected two genotypes, one represented by strain Temecula (causing grapevine Pierce's disease) and the other by strain Dixon (causing ALSD), from early passage of X. fastidiosa cultures from infected almonds. The two genotypes were correlated with colony morphology variations. This is the first report of mixed strain infection of almond by different X. fastidiosa genotypes under natural environmental conditions