Comparison of Resistance of Grass Weeds to Clodinafop-Propargyl Using Glass-House and Molecular Methods

In order to evaluate the efficacy of molecular method to detect the resistance of weeds to herbicides, 69 resistant or susceptible grass weed biotypes to clodinafop propargyl herbicide, including Lolium spp. (6 biotype), Avena spp. (30 biotype), and Phalaris spp. (33 biotype) were studied, dCAPS method as a simple method to diagnosis Ile1781Leu amino acid substitution in ACCase enzyme was used. The results of greenhouse experiment for Avena spp., Phalaris spp. and Lolium spp. were 90%, 79% and 100% similar to molecular experiment respectively. In general, the similarity of molecular method with current methods was about 85%. Isoleucine (Ile) to leucine (Lue) substitution at position 1781 (Ile /Leu) was the most common amino acid substitution selected with ACCase-inhibiting herbicide. The partial differences (about 15%) between glass-house and molecular methods also can explain by non-target site mechanism (enhancing metabolism) or another amino acid substitution.