Nationwide Survey Using Real-Time PCR in 2024 and 2025 Supports the Absence of Xylella fastidiosa in Korea.

Xylella fastidiosa is a plant-pathogenic bacterium that causes severe diseases in economically important crops, such as citrus and grapevine, thereby posing a significant threat to global agriculture. Although X. fastidiosa has not yet been reported in Korea, the increase in international trade and its presence in neighboring countries highlight the necessity of continued surveillance. The objective of this study was to verify the absence of X. fastidiosa in Korea and to establish a reliable diagnostic framework through a nationwide survey conducted in 2024 and 2025. The sampling design was generated using the RiBESS+ statistical model to ensure the reliability of the survey results. Host plants, including grapevines (Vitis vinifera), mandarin oranges (Citrus unshiu), and cherry blossoms (Prunus yedoensis), were selected and sampled from urban and agricultural areas throughout the country for a nationwide survey. Genomic DNA was extracted from plant petioles and analyzed using real-time PCR with an optimized primer set (XF16S-F/R). Over a period of two years, a total of 2,314 samples were collected, exceeding the required sample size of 843 per year. X. fastidiosa was not detected in any of the collected and tested samples. These results confirm the absence of X. fastidiosa in Korea throughout the study period with high statistical confidence. This study provides evidence confirming the absence of X. fastidiosa in Korea and proposes a standardized methodology for future surveillance and early detection of other invasive prohibited quarantine pests.