Abstract: Colletotrichum camelliae is the dominant pathogen causing tea anthracnose. This disease causes significant defoliation, which has a major impact on the following year's yield and results in great economic losses. Therefore, the early and timely detection of C. camelliae in tea leaves is of great significance for effective control of anthracnose in production. In this study, based on a loop-mediated isothermal amplification (LAMP) assay, a specific gene encoding a late embryogenesis abundant (LEA) domain protein from C. camelliae was selected for the design of LAMP primers. Three pairs of specific LAMP primers, including two outer primers, two inner primers, and two loop primers, were designed and selected. Subsequently, a LAMP assay for C. camelliae was established through specificity and sensitivity tests, and by detecting C. camelliae in artificially inoculated and infected tea leaves. The optimal reaction condition was determined to be at 65 ℃ for 30 min. The results were verified by 2% agarose gel electrophoresis with SYBR Green Ⅰ added. Specificity tests reveal that, only DNA extracted from C. camelliae isolates exhibited a positive amplification reaction. In sensitivity tests, the assay could detect genomic DNA templates of C. camelliae at a minimum concentration of 100 ag·µL^-1. The LAMP assay accurately detected C. camelliae in artificially inoculated diseased leaves and anthracnose-affected leaves of 18 tea germplasms in the field. In summary, the LAMP assay for detecting C. camelliae established in this study has the advantages of rapid, simple and high sensitivity, enabling the specific detection of C. camelliae and the quick diagnosis of tea anthracnose.

Key words: tea anthracnose, Colletotrichum camelliae, loop-mediated isothermal amplification, disease detection, specific gene