Detection of Acetyl-CoA Carboxylase (ACCase) Inhibitor Herbicides Resistance in Sterile Wild Oat (Avena sterilis L.) Using Agar Quick Test

This study was conducted using seeds in Petri dish containing agar medium in order to determine acetyl-CoA carboxylase (ACCase) herbicides resistance (R) in Avena sterilis that was grown in wheat fields at Adana province, Turkey. Seeds were collected from one large suspected field, where clodinafop-propargyl (Aryloxyphenoxypropionate “FOPs”) and pinoxaden (Phenylpyrazoline “DEN”) have been applied for many years. Susceptible (S) population was collected from the road side on the same region. Agar media of concentration 14 g/L was prepared and it was melted in microwave. Then the amount of 20 mL agar media was added into each Petri dish. Five seeds were placed on agar mediums containing discriminating dose of clodinafop and pinoxaden. Petri dishes were placed in growth incubator operating at 10 °C. After 15 d, both radicle and hypocotyl length were measured. The percentage of germinated seed and dose-response curves were determined. At these different concentration levels, there were more than 50% of R and less than 40% of S seed germinated for pinoxaden. However, for clodinafop, more than 60% of R and less than 50% of S seeds were germinated. At higher concentration levels, the populations of resistant and susceptible were not germinated for both herbicides. The resistance value of R population was then compared with that of the S biotype. From the resistance index (RI), the population was more resistant to pinoxaden (7.43 for radicle and 2.47 for hypocotyl) than the clodinafop-propagyl (1.39 for radicle and 3.77 for hypocotyl). The method provided a simple, quick and cost effective way to identify ACCase herbicides resistance in most grass weeds.