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ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Floral and Nursery Plants Research » Research » Research Project #432862

Research Project: Specific Detection of Xylella Fastidiosa Subspecies Pauca-CoDiRO Strain Using Molecular Approaches

Location: Floral and Nursery Plants Research

Project Number: 8020-22000-042-06-I
Project Type: Interagency Reimbursable Agreement

Start Date: May 1, 2017
End Date: Sep 30, 2018

Objective:
Olive trees on the west coast of Italy began to decline and die in 2010 as a result of a disease known as Olive Quick Decline Syndrome. These trees were discovered to be infected with Xylella fastidiosa (Xf) subspecies pauca – CoDiRO strain. The spread of the bacteria since 2013 prompted the California Department of Food and Agriculture and California olive growers to ask USDA PPQ S&T to investigate the matter. The USDA National Pest Advisory Group reported on this strain in 2015 and hypothesized that a pathway for the introduction of this pathogen is through landscape and ornamental plants. The report concludes with a recommendation to evaluate and validate Xf-CoDiRO strain-specific detection protocols. The main goal of this project is to develop, evaluate, and validate real-time PCR (qPCR) for the detection of Xylella fastidiosa subspecies pauca-CoDiRO strain.

Approach:
Approach for the year: 1st quarter • The Huang lab at ARS-Beltsville will continue gathering DNA from representative X. fastidiosa strains to broaden the collection. • CPHST-Beltsville Laboratory (CPHST-BL) plans to develop primers and probe for the detection of the CoDiRO strain using the TaqMan PCR assay. • CPHST-BL will validate the qPCR test and perform quality controls, including calculating reaction efficiency. 2nd quarter CPHST-BL will: • Test the feasibility of duplexing the mulberry/CoDiRO specific qPCR assay with other qPCR assays in the PPQ protocol for X. fastidiosa testing. • Use DNA from cultures of X. fastidiosa strains and from bacterial plant pathogens with similar hosts to evaluate TaqMan primers and probe. 3rd quarter CPHST-BL will: • Validate assays using the DNA collection in the Huang lab. • Prepare draft Work Instructions and Work Flowcharts to incorporate the addition of CoDiRO strain detection. 4th quarter CPHST-BL will: • Finalize Work instructions and Work Flowcharts. • Develop training courses or slides that instruct members of the diagnostic community on the Work Instructions to successfully complete the protocols.