APS Homepage

POSTERS: Pathogen detection, quantification and diagnosis

Comparative study of methods for detecting Xylella fastidiosa causing bacterial leaf scorch in blueberry
Emran Ali - University of Georgia. Owen Hudson- University of Georgia, Sumyya Waliullah- University of Georgia, Jonathan Oliver- University of Georgia, Pingsheng Ji- University of Georgia

Bacterial leaf scorch, caused by Xylella fastidiosa, is a major threat to blueberry production in the southeastern United States. Management of this devastating disease is challenging and often requires early detection of the pathogen to reduce major loss. There are several different molecular and serological detection methods available to identify the pathogen. Knowing the efficiency and suitability of these detection techniques for application in both field and laboratory conditions is important when selecting the appropriate detection tool. Here, we compared the efficiency and the functionality of four different molecular detection techniques (PCR, real-time PCR, LAMP and AmplifyRP® Acceler8™) and one serological detection technique (DAS-ELISA). The most sensitive method was found to be real-time PCR with the detection limit of 25 fg of DNA molecules per reaction (?9 genome copies), followed by LAMP at 250 fg per reaction (?90 copies), AmplifyRP® Acceler8™ at 1 pg per reaction (?350 copies), conventional PCR with nearly 1.25 pg per reaction (? 440 copies) and DAS-ELISA with 1x105 cfu/mL of Xylella fastidiosa. Considering robustness, portability, and cost, LAMP and AmplifyRP® Acceler8™ were not only the fastest methods, but also portable to the field and didn’t require any skilled labor to carry out. Among those two, AmplifyRP® Acceler8™ was faster but more expensive and less sensitive than LAMP. These findings should enable growers, agents, and diagnosticians to make informed decisions regarding selection of an appropriate diagnostic tool for X. fastidiosa on blueberry.