Monitoring Of Wheat Aphid Resistance To Insecticides And Study On The Mechanism Of Resistance To Bifenthrin In Anhui Province

The Sitobion avenae(Fabricius)and the Rhopalosiphum padi(Linnaeus)are important pests on wheat crops,and Anhui Province,as one of the main wheat producing areas in China,is deeply affected by them.Bioassays were conducted to determine whether wheat aphids from different regions have developed differential resistance,and transcriptome sequencing,RNAi,and other techniques were used to further explore the resistance mechanism that produces differential resistance.The results of the study will provide scientific basis for the regional management and sustainable control of S.avenae and R.padi in Anhui Province.The main research results are as follows:1.Monitoring of insecticide resistance of S.avenae and R.padiFive insecticides were used to monitor the resistance of S.avenae and R.padi in several areas of Anhui Province.The results showed that the S.avenae from Chuzhou Mingguang,Ma’anshan Hexian,and Huainan Fengtai areas in showed high levels of resistance to imidacloprid.The S.avenae from various areas were still at a sensitive level to Thiamethoxam and acetamiprid,with resistance multiples less than 5;The resistance of the R.padi in the Mingguang area of Chuzhou to bifenthrin was 568.5 times higher than that in the laboratory.In different regions,the R.padi also showed varying degrees of resistance to acetamiprid and thiamethoxam,but the overall resistance difference was small,with resistance multiples ranging from 0.53 to 5.93.2.Sequencing and screening of differential genes in the transcriptome of R.padiTranscriptome sequencing of RNA of two groups of R.padi(laboratory sensitive strain and Chuzhou Mingguang R.padi)with different resistance to bifenthrin.A total of 74 differential genes were selected,and five different genes were selected for RT-q PCR detection,the detection results were consistent with the transcriptome sequencing results.Three differentially expressed genes were selected and named Rphsp70-1,Rphsp70-2,and Rphsp70-3 through base sequence alignment,encoding 641,637,and 637 amino acids,respectively.The sequence consistency of the three genes reached over 90%,and all had three identical conserved domains(HSP70 family signature motif).3.The relationship between RNAi validation of differential genes and resistance to bifenthrin in R.padiSynthesize Rphsp70-1,Rphsp70-2,and Rphsp70-3 gene ds RNAs,and perform RNAi on the R.padi in the Dangshan area of Suzhou using soaking method.The results show that after 24 hours,the expression levels of the three genes are significantly down regulated.There is no significant difference in the mortality rate of the rice aphid between the ds GFP group and the ds Rphsp70-1,ds Rphsp70-2,and ds Rphsp70-3 groups.However,bioassay of the RNAi infected R.padi showed a significant difference in the mortality rate between the ds GFP group and the ds Rphsp70-3 group,but there was no significant difference compared to the other two groups.