IMMUNOCAPTURE AND MULTIPLEXED-PCR ASSAY FOR XANTHOMONAS FRAGARIAE, CAUSAL AGENT OF ANGULAR LEAFSPOT DISEASE

Angular leaf spot disease, caused by Xanthomonas fragariae, has become an important strawberry disease in the United States in recent years.
We previously used three polymerase chain reaction (PCR)-based techniques to identify polymorphisms so that we could determine genetic relationships among and diversity within X. fragariae. Amplification products unique to X. fragariae were cloned, sequenced and used to develop PCR-based assays specific for X. fragariae. Three primer sets, each directing an amplification product specific for X. fragariae, were used together in a single multiplexed-PCR assay.
The assay has a sensitivity in the range of 100–1000 cells per assay.
In order to eliminate inhibitors of the PCR present in strawberry extracts, polyclonal rabbit antiserum raised against the type strain of the species was used to label bacteria in solution prior to indirect immunocapture with super paramagnetic beads coated with sheep anti-rabbit IgG. This method will be useful in phytosanitary quarantine, screening germplasm or plants prior to distribution, and for detailed studies of the movement of the pathogen in planta.

III International Strawberry Symposium

J.S. Hartung, M.R. Pooler

strawberry, Fragaria x ananassa, disease, polymerase chain reaction, PCR, detection

https://doi.org/10.17660/ActaHortic.1997.439.136