Tribenuron‐methyl resistance in catchweed bedstraw ( Galium aparine ): status and MIRA ‐based rapid detection of ALS D376E mutation

BACKGROUND Catchweed bedstraw ( Galium aparine ) is a highly competitive malignant broadleaf weed that significantly reduces the yield and quality in wheat and rapeseed cropping systems. The prolonged and exclusive use of tribenuron‐methyl has led to widespread resistance development, posing a significant threat to the sustainability of weed management practices. To enable timely intervention and support evidence‐based decision‐making, systematic monitoring of resistance status and the development of a rapid, reliable detection method are urgently required. RESULTS We collected 113 populations of G. aparine from major wheat‐growing regions across China, among which 83 populations were found to be resistant to tribenuron‐methyl. The sequencing of the ALS gene revealed six distinct mutation patterns at sites P197, D376 and W574 within resistant populations, among which D376E was the most frequently observed. To enable rapid field resistance monitoring, the multienzyme isothermal rapid amplification (MIRA) assay was developed for detecting the D376E mutation. This new detection system can assess target‐site resistance within 80 min at a constant temperature of 39 °C. CONCLUSION This study investigated tribenuron‐methyl resistance in 113 G. aparine populations from various provinces of China and generated a comprehensive resistance distribution map. The MIRA‐based method for rapidly detecting the ALS D376E substitution in G. aparine was developed. Collectively, our study provides valuable knowledge and a practical tool for the management of G. aparine .