Development of a LAMP assay for strawberry anthracnose Colletotrichum fructicola

Abstract Anthracnose is major disease seriously affecting the strawberry industry. Particularly, Colletotrichum fructicola, which is memberof the C. gloeosporioides species complex, is widely distributed and causes severe yield loses in strawberry crops around the world. Universal loop-mediated isothermal amplification (LAMP) detection methods for Colletotrichum spp., have been reported. Here, we report our development of a new LAMP assay for C. fructicola based on sequences amplified by the Ap-f3/Ap-r7 primer set. These LAMP primers discriminated C. fructicola and C. aenigma strains from C. acutatum AS-2, C. fioriniae, C. nymphaeae, C. siamense, and other fungi. The LAMP method used herein demonstrated higher detection sensitivity than PCR using the Ap-f3/Ap-r7 primer set. The DNA extracted using this kit is recommended as best suited for performing the LAMP assay to select strawberry seedlings hosting C. fructicola during incubation. In contrast, latent infection with C. aenigma in strawberry seedlings could not be detected by the LAMP assay. This finding suggests that the primer sequence affects detection sensitivity of the assay.