ARS | Publication request: A HIGH-THROUGH-PUT MULTI-LOCUS PATHOGEN DETECTING SYSTEM FOR STRAIN IDENTIFICATION AND POPULATION GENETIC STUDIES OF XYLELLA FASTIDIOSA

Submitted to: Phytopathology
Publication Type: Abstract
Publication Acceptance Date: March 29, 2005
Publication Date: July 30, 2005
Citation: Lin, H., Civerolo, E.L., Groves, R.L., Takahashi, Y., Walker, A. 2005. A high-through-put multi-locus pathogen detecting system for strain identification and population genetic studies of Xylella fastidiosa. Phytopathology. 95(6):S61.

Technical Abstract: The bacterium Xylella fastidiosa (Xf) causes Pierce¿s disease of grape (PD) and almond leaf scorch disease (ALSD), as well as economically important diseases of a number of other fruit crops and ornamental plants. We developed a multiplex diagnostic platform for Xf genetic analysis using a multi-locus simple sequence repeat (SSR) DNA marker system. This system employs a multiple fluorescent-labeled genotyping format analyzed by an ABI 3100 genetic analyzer. We combined this system with our rapid sample preparation protocol to create a high-through-put Xf pathogen diagnostic and genetic analysis system. Genetic analyses of California¿s Xf populations were performed with this system by testing PD-associated Xf strains from four grape growing counties and ALSD-associated Xf strains from the San Joaquin Valley¿s almond growing regions. This pathogen detection system worked well for both plants (grape and almond) and insects (green sharpshooter and glassy-winged sharpshooter). The system avoids the time-consuming bacterial isolation step and reduces the chance of sample loss due to contamination and culture difficulties. The sensitivity, specificity and ability to detect Xf polymorphism in plant and insect hosts make this system an ideal tool for studies of Xf genetics and epidemiological risk assessment analyses.