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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #393012
Research Project: Development of Applied Management Systems for Diseases of Perennial Crops with Emphasis on Vector-Borne Pathogens of Grapevine and Citrus

Location: Crop Diseases, Pests and Genetics Research

Title: TaqMan PCR detection of Xylella taiwanensis in Taiwan

Author
item SU, CHIOU-CHU - Taiwan Agricultural Chemicals And Toxic Substances Research Institute
item FUNG, JIE-AN - Taiwan Agricultural Chemicals And Toxic Substances Research Institute
item CHANG, RUEY-JANG - Taiwan Agricultural Chemicals And Toxic Substances Research Institute
item CHANG, CHUNG-JAN - University Of Georgia
item JAN, FUN-JYH - National Chung-Hsing University
item SHIN, HSIEN-TZUNG - Taiwan Agricultural Research Institute
item Chen, Jianchi

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/6/2022
Publication Date: 12/26/2022
Citation: Su, C., Fung, J., Chang, R., Chang, C., Jan, F., Shin, H., Chen, J. 2022. TaqMan PCR detection of Xylella taiwanensis in Taiwan. American Phytopathological Society Meeting. 112:S3.85.

Interpretive Summary:

Technical Abstract: Xylella taiwanensis (Xt) is a nutritionally fastidious bacterial pathogen causing pear leaf scorch disease (PLSD) in Taiwan. Infection of Xt causes leaf scorching symptoms, reduces tree vigor, and reduces fruit yield. Early and accurate diagnosis of PLSD is important for PLSD management. While leaf scorching is an initial indicator, diagnosis of PLSD has been exclusively based on PCR detection of Xt. Only one primer set, PLS-F/R, has been published for the standard PCR format (agarose gel electrophoresis). In this study, five Xt specific TaqMan PCR primers/probe sets were developed and evaluated. The PCR systems targeted three conserved genomic loci commonly used for bacterial pathogen detection: 16S rRNA gene (rrs), 16S-23S intergenic transcribed sequence (16S-23S ITS), and a DNA gyrase gene (gyrB), which were readily available in published whole genome sequences of Xt. Locus copy number and nucleotide variations were considered for primer and probe designs. BLAST analysis using the GenBank nr sequence database showed that the TaqMan primers and probes were highly specific to Xt. The five TaqMan PCR systems were tested using DNA samples from pure cultures of Xt, Xylella fastidiosa, and PLSD plant tissues. A metagenomic analysis of a selected PLSD sample was performed to further evaluate PCR accuracy.