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

## TL;DR

This paper introduces two new methods for detecting a pathogen that causes brown spot disease in European plums, which is important for protecting the plum industry.

## Contribution

The development of two highly specific and sensitive detection methods for Alternaria alternata using LAMP technology.

## Key findings

- LAMP-Cresol Red and LAMP-SYBR Green I methods can detect Alternaria alternata with high specificity.
- Both methods have detection limits at the femtogram level, surpassing conventional PCR techniques.

## Abstract

European plum (Prunus domestica 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 Alternaria alternata (Fr.) Keissl. Outbreaks of this disease severely hinder both domestic and global development of the European plum 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 A. alternata: LAMP-Cresol Red chromogenic visible endpoint detection and LAMP-SYBR Green I real-time fluorescent detection. Both methods demonstrate high specificity for A. alternata, 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 European plum industry, and contributes significantly to global disease prevention, control, and industrial stability for this crop.