Abstract
A blackgrass population has developed resistance to fenoxaprop-P-ethyl following field selection with the herbicide for 6 consecutive years. Within this population, 95% of the individuals are also resistant to flupyrsulfuron. Both the inheritance(s) and the mechanism(s) of resistances were investigated by making crosses between the resistant and a susceptible biotype. The inheritance was followed through the F1 and F2 generations either by spraying the herbicide on seedlings at the three-leaf stage or using a seedling bioassay, based on coleoptile length. No maternal effects were evident in the fenoxaprop-P-ethyl responses of the F1 plants, suggesting that the inheritance was nuclear. Some F1 families treated with fenoxaprop-P-ethyl segregated in a 3:1 (resistant:susceptible) ratio, indicating that the resistance was conferred by two dominant and independent nuclear genes. This was confirmed by the 15:1 (R:S) ratio observed in the F2 generation treated with fenoxaprop- P-ethyl. The use of selective inhibitors of herbicide de-toxifying enzymes (aminobenzotriazole, pyperonylbutoxide, malathion and tridiphane) with the F2 plants suggested that each of the two genes may govern two different mechanisms of fenoxaprop-P-ethyl resistance: the ACCase mutation previously postulated and an enhanced herbicide metabolism, mediated by cytochrome P 450 mono-oxygenases (P 450) susceptible to malathion. The P 450 activity may also confer resistance to flupyrsulfuron. This study clearly indicates that two distinct mechanisms of resistance may co-exist in the same plant.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 18 August 2000 / Accepted: 6 December 2000
Rights and permissions
About this article
Cite this article
Letouzé, A., Gasquez, J. Inheritance of fenoxaprop-P-ethyl resistance in a blackgrass (Alopecurus myosuroides Huds.) population. Theor Appl Genet 103, 288–296 (2001). https://doi.org/10.1007/s001220100607
Issue Date:
DOI: https://doi.org/10.1007/s001220100607