The Metabolic Resistance Of Alopecurus Japonicus To Fenoxaprop-p-ethyl

The occurrence of weeds in wheat field is serious in China,among which the gramineous is the most common one,while the control effect of Alopecurus japonicus Steud,is getting worse and worse,which seriously affects the quality and yield of wheat.Fenoxaprop-p-ethyl is an APP herbicide and is mainly used in gramineous weeds.In recent years,fenoxaprop-p-ethyl has been unable to effectively control the Alopecurus japonicus,and even some areas have developed multi-resistance,which is the direction of great concern.In this study,we found that the resistance of Alopecurus japonicus to fenoxaprop-p-ethyl was related to the target mutation,and there might be non-target resistance mediated by GSTs metabolic enzymes.To clarify the resistance level and the mechanism of metabolism resistance to fenoxaprop-p-ethyl of Alopecurus japonicus,to provide experimental materials for the study of metabolism resistance,to delay the occurrence of weed resistance,and to provide theoretical basis for the effective control of weeds in the field.Based on the progress of the research group,the metabolic resistance of Alopecurus japonicus to fenoxaprop-p-ethyl was studied.The main results were as follows:(1)The drug resistance levels of Alopecurus japonicus populations from different regions were determined,and it was found that eight populations(AH40,AH41,AH42,AH43,AH44,JS19,JS20 and JS21)had developed different degrees of drug resistance to Fenoxazole prop-p-ethyl.The population with the highest resistance level was AH41,whose relative resistance level was 48.2.The GR50 value of the Alopecurus japonicus was much higher than the recommended dose.The results showed that the Fenoxazole prop-p-ethyl was no longer able to effectively control the Alopecurus japonicus.(2)The effect of Cytochrome P450 oxidase inhibitor PBO and Malathion on fenoxaprop-p-ethyl was determined by whole-plant bioassay,the results showed that the cytochrome P450 oxidase inhibitors increased the sensitivity to fenoxaprop-p-ethyl of AH40,AH41,AH42 and AH43 of Alopecurus japonicus populations,but still had some resistance to fenoxaprop-p-ethyl,it may be that there are other target resistance or non-target resistance in Alopecurus japonicus.(3)The effects of GSTs inhibitors such as tridiphane,4-chloro-7-nitrobenzaldehyde and cyanuric chloride on Fenoxaprop-p-ethyl were determined by whole plant bioassay.The results showed that the populations of AH40,AH41,JS19,and JS20 may have GSTs-mediated metabolic resistance,and the GSTs inhibitor significantly increased the sensitivity of Alopecurus japonicus to Fenoxazoleprop-p-ethyl.The GR50 value was still higher than the recommended dose,indicating the possibility of target resistance or non-target resistance.The GR50 values of AH44 and JS16 populations did not change significantly,possibly because the resistance of these two populations was caused by other target resistance or non-target resistance.(4)In this experiment,resistance spectrum was determined for Alopecurus japonicus,and the results were as follows:AH41,AH42,AH43,AH44,JS19 and JS20 had interactive resistance to ACCase inhibitor herbicides.AH40,AH41,AH42,AH43,JS18,JS19 and JS21 had interactive resistance to herbicides containing ALS inhibitors.AH41,AH42,AH43 and JS19 developed multiple resistance to ACCase inhibitors and ALS inhibitors.In conclusion,the resistance level of Alopecurus japonicus to Fenoxaprop-p-ethyl has been determined in this study.P450s enzyme inhibitor and GSTs inhibitor have synergism to the medicament,which indicates that there is metabolic resistance in the resistance mechanism of Alopecurus japonicus,and provides theoretical basis for elucidating the mechanism of metabolic resistance.The cross-resistance and multi-resistance of Alopecurus japonicus to ACCase inhibitor and ALS inhibitor were studied.