Study On The Difference In Herbicide Tolerance Of Wheat Varieties To Mesosulfuron-methyl And Other Herbicides

Mesosulfuron-methyl,pyroxsulam and fluxazone-sodium belonging to ALS inhibitor herbicides of selective post-emergenceare still widely used in wheat fields in China.However,it occurs frequently that these three herbicides could cause phytotoxicity in some sensitive wheat varieties.Some previous studies indicate that different varieties of the same crop have different herbicides tolerance.Screening herbicide-tolerant varieties is an effective way to reduce the phytotoxicide of crops.In order to determine the level and mechanism of tolerance of different wheat varieties to herbicides,this study was arranged to measure the tolerance of40 kinds of wheat commonly used in the Huanghuaihai basin to three kinds of herbicides,including mesosulfuron-methyl,pyroxsulam and fluxazone-sodium,and which of sensitive and tolerant wheat varieties were determined their tolerance mechanism by the pot method in greenhouse or root length-peti dish.This study can provide a reference for solving herbicides’ phytotoxicity of winter wheat,and the theoretical guidance for the rational use of herbicides.The main research results are as follows:1.Herbicide tolerance of all 40 varieties of wheats were measured at the minimum,intermediate and maximum dose of the recommended doses used for field by the pot method in greenhouse and root length-petri dish.The results indicated that Zhoumai 27,Shixin 828 and Shimai 22 are all more sensitive to these three herbicides,while Bainong AK58,Jimai585 and Zhengmai 379 all more tolerant to these three herbicides.2.The dose response curve was determined for three sensitive wheats(Shixin 828,Zhoumai27,Shimai 22)and three tolerant wheats(Bainong AK58,Jimai 585,Zhengmai 379).The results showed that the inhibition rate and growth rate of these three herbic Ides between the herbicide-tolerant wheats and the sensitive wheats were different,though the tendency of the dose response curve was almost same among the six varieties.Moreover,Shixin 828 was more sensitive to all three herbic Ides than the other two sensitive wheats,and Jimai 585 was more tolerant to mesosulfuron-methyl and fluxazone-sodium and shimai 22 was more tolerant to pyroxsulam among three tolerant wheats,which was consistent with the previous sensitivity identification test results.3.The relative activity of glutathium-S-transfer of the sensitive wheats(Shixin 828,Zhoumai 27,Shimai 22)and the tolerant wheats(Zhengmai 379,Jimai 585,and Bainong AK58)were measured at the same doses of mesosulfuron-methyl,myroxsulamand fluxazone-sodium.The results showed that the GSTs activity of the tolerant wheats was higher than that of sensitive wheats.And the GSTs activity of the tolerant wheats reached the highest level the next day after the treatment,while the sensitive wheats reached on the third day,and lower than the highest level of GSTs activity of the tolerant wheats.After the treatment,the GSTs activity of the Jimai 585 was the highest,while the GSTs activity of the Shixin 828 was the lowest,indicating that the Jimai 585 was more tolerant than the Shixin828,and the GSTs activity works vital rolein herbicide tolerance.4.Through the study of target enzyme acetyllactase synthetase between shixin 828 and ji585,the results showed that after the treatment of mesosulfuron-methyl,pyroxsulam and fluxazone-sodium at the same doses,Shixin 828 has lower relative activity,stronger inhibition,and slower recovery than Jimai 585,which indiceted further that Shixin 828 was sensitive to mesosulfuron-methyl,pyroxsulam and fluxazone-sodium,and Jimai 585 was more tolerant to herbicide than Shixin 828.In conclusion,this study indicated that among the many varieties commonly used in the Huanghuaihai basin,the herbicide tolerance of 40 wheat varieties to mesosulfuron-methyl,pyroxsulam and fluxazone-sodiumchemicals is different significantly.Shixin 828,Zhoumai27,and Shimai 22 are more sensitive to three types of herbicides,and Bainong AK58,Jimai585,and Zhengmai 379 have better tolerance to three types of herbicide among these 40 wheats.The relative activity of metabolic enzymes GSTs is one of the differences in herbicide tolerance of wheats,and ALS activity may be another one,too.