A GWAS to Reveal the Underpinnings of Metribuzin Tolerance in Oats

Oats (Avena sativa L.) are a promising break crop due to their dense canopy and allelopathic properties, but their susceptibility to herbicides limits establishment. This study evaluated genetic variation in response to the photosystem II-inhibiting herbicide metribuzin (300 g ai ha⁻¹) in a diverse oat panel. Phenotypic response was assessed using visual injury ratings, and best linear unbiased estimates (BLUEs) were calculated to account for experimental variation.Genome-wide association analysis identified significant loci associated with metribuzin response. Candidate genes proximal to associated loci included WAT1, MAP65-5, and DRIP2, which are implicated in stress response and cellular integrity. These results provide insight into the genetic architecture of metribuzin tolerance in oats and highlight loci for potential use in breeding programs.