Use of LAMP for Assessing Colonization of Bunch Trash and Latent Infection of Berries in Grapevines.

A real-time loop-mediated isothermal amplification (LAMP) assay was evaluated for the detection of in grapevine bunch trash, immature berries, and ripening berries. A simple method for the preparation of crude extracts of grape tissue was also developed for on-site LAMP analysis. When tested with 14 other fungal species frequently found in grapevines, the LAMP assay was specific and sensitive to a DNA quantity of 0.1 ng/µL. The sensitivity was further tested using bunch trash samples with colonization levels between 6 and 100% and with bulk-berry samples composed of 4 pathogen-free berries or 4 berries among which 25 to 100% had been inoculated with . The LAMP assay detected the lowest colonization level tested in bunch trash and in immature and mature berries in less than 20 min. In single-berry experiments, LAMP amplified DNA from all artificially inoculated individual immature and mature berries. No amplification occurred in -free material. The real-time LAMP assay has the potential to be used as a rapid on-site diagnostic tool for assessing colonization in bunch trash and latent infections in berries, which represent critical stages for decision-making about disease management.