6533b85dfe1ef96bd12be542

RESEARCH PRODUCT

Vulpin et ivraies, détecter vite les résistances à certains herbicides blé

subject

description

Herbicides inhibiting acetolactate-synthase (ALS) are currently of major importance for grass weed control in wheat in France. Rapid resistance diagnosis can help upholding their efficacy. Most cases of resistance to ALS-inhibiting herbicides are due to mutations in the gene encoding ALS. DNA-based assays were developed to detect any ALS mutation endowing resistance in black-grass (Alopecurus myosuroides) and ryegrasses (Lolium spp.). These tests enable resistance diagnosis from leaf fragments, even dried, within 48 hours. They were used to analyse black-grasses and ryegrasses sampled in fields where ALS inhibitor application failures were reported. The tests detected high frequencies of ALS mutations in 9 out of the 22 samples analysed. ALS-based resistance can likely evolve rapidly in some cases, especially when herbicide spraying programs are mostly based upon ALS inhibitors targeting grass weeds. This emphasizes the need to ponder ALS inhibitor applications, and to use them in association with the highest possible diversity of cultural practices.