Characterization of mutations conferring inherent resistance to acetyl coenzyme A carboxylase‐inhibiting herbicides in turfgrass and grassy weeds

Abstract

AbstractAn herbicide‐resistant weed control system that utilizes naturally occurring mutations to acetyl‐coenzyme A carboxylase (ACCase)‐inhibiting herbicides could provide herbicide selectivity and improve control of grassy weeds in turf. Knowledge regarding the presence of these mutations in grasses is needed to guide development of this type of system. This research subjected 24 species of warm‐season, cool‐season, and grassy weed species to rates of 0, 400, and 1200 g a.i. ha−1 of fenoxaprop herbicide and surveyed these species for the presence of site‐of‐action mutations in ACCase at amino acid (aa) positions 1781, 1999, 2027, 2041, 2076, 2088, and 2096. Nine species including Agrostis capillaris L., Festuca ovina L., Festuca rubra L., Lolium multiflorum Lam., Lolium perenne L., Paspalum dilatatum Poir., Poa annua L., Zoysia japonica Steud., and Z. matrella [L.] Merr. were tolerant to fenoxaprop. Site of action point mutations conferring resistance to ACCase herbicides were found at aa position 1781 in only three of 24 species surveyed (Festuca ovina, Festuca rubra, and Poa annua). The information obtained from this study provide guidance for the development of ACCase resistant weed control systems for turfgrass.