Resistance Of Eleusine Indica To Quizalofop-p-ethyl In Cotton Fields In Hunan Province

In order to investigate the resistance of Eleusine indica populations to quizalofop-p-ethyl,9potential resistant populations were collected from Some Cotton fields9cities in Changde, Yueyang, Yiyang, and1susceptible populations was collected from Nanxian never applied herbicides. Based on the work done above, the populations from Xiangyin R and Nanxian S were selected, and the enzymology mechanism of resistance was discussed by the research on the important plant metabolic enzyme glutathione-s-transferase(GSTs), and the protective enzyme (SOD, POD, CAT). The suspectibility of Eleusine indica resistance to quizalofop-p-ethyl to different herbicides were determined by whole plant bioassay.Main results as follows:(1) The results of whole-plant bioassay showed that populations of Eleusine indica from the collecting sites of Hunan Province developed different levels of resistance to quizalofop, and The resistance level of Xiangyin R was the highest, GR50of Xiangyin R was9.721mg·L-1, GR50of Nanxian S was9.721mg·L-1; RI was9.7; GR50of other sites were14.345～55.421mg·L-1, RI were2.4-9.2.The results of whole-plant bioassay showed that populations of Eleusine indica from the collecting sites of Hunan Province developed different levels of resistance to quizalofop.(2) The activity of GST in resistant plants were higher than that in sensitive ones without herbicide treatment. GST reductase activity in both resistant and susceptible individuals showed increased firstly and then decreased. In resistant populations, GST activity showed a trend of sharply changes, while the sensitive populations sensitive populations showed flat trend after herbicide spraying.(3) The activity of SOD, CAT, POD in resistant and suspectible populations of Eleusine indica were detected. Significant differences of all the indexes mentioned above were observed in resistant and sensitive populations after treated by quizalofop-p-ethyl. After14days,the SOD and POD activity of R and S populations were didn’t change significantly,and the SOD, POD and CAT activity of R populations were significantly lower than CK.But the S populations were no significant difference. Therefore, oxidative stress is related with the mechanisms of resistance in Eleusine indica.(4) The results of whole-plant bioassay showed that this resistant population was also resistant to haloxyfop-R-ethyl and Fenoxaprop-p-ethyl. Also this resistant population remained to be suspectible to the other herbicides, which had different mode of action.