Development and Comparison of Visual Colorimetric Endpoint LAMP and Real-Time LAMP-SYBR Green I Assays for Alternaria alternata (Fr.) Keissl in European Plum

<i>European plum</i> (<i>Prunus domestica</i> L.) is widely cultivated worldwide, with China producing 6.8 million t annually (55% of the global total output). However, the Kashgar region of Xinjiang, China's primary production area, has experienced outbreaks of brown spot disease caused by <i>Alternaria alternata</i> (Fr.) Keissl. Outbreaks of this disease severely hinder both domestic and global development of the <i>European plum</i> industry. Because this pathogen has a strong latent infection capability during the early stages of disease development, its early detection is important. We develop two detection methods targeting the ITS sequence of <i>A. alternata</i>: LAMP-Cresol Red chromogenic visible endpoint detection and LAMP-SYBR Green I real-time fluorescent detection. Both methods demonstrate high specificity for <i>A. alternata</i>, enabling stable detection of the pathogen in various plant samples; detection limits reach the femtogram (fg) level, significantly surpassing conventional PCR detection capabilities. Development of these highly efficient and precise early detection methods provides a solid foundation for sustainable development of China as a global hub of the <i>European plum</i> industry, and contributes significantly to global disease prevention, control, and industrial stability for this crop.