Genetic Diversity Analysis And Bt Resistance Monitoring Of Helicoverpa Armigera In Different Regions Of Xinjiang

Bt cotton has been planted in Xinjiang for 20 years,and the potential resistance risk of Helicoverpa armigera to Bt cotton is increasing.Based on GBS simplified genome sequencing technology,this study analyzed the genetic diversity of H.armigera in different regions of Xinjiang,analyzed the whole genome association of feeding（Bt cotton and non Bt crops）,used DIMBOAl as a marker,used UPLC-MS/MS to determine the content of DIMBOA in H.armigera,analyzed the proportion of sensitive H.armigera,and used single female F₁ generation method to determine the frequency of Bt resistance gene,In order to understand whether there is gene exchange among natural populations of H.armigera in the South and North of Xinjiang,and the regulatory role of maize shelter on Bt resistance of H.armigera,so as to provide scientific basis for mining Bt resistance genes of H.armigera,resistance monitoring and management.（1）Based on the simplified genome sequencing of GBS,the samples of H.armigera in 8 places in Xinjiang were sequenced,and 141797650 sequencing sequences were obtained.Through the detection of base quality,Q20,Q30 and comparison rate,the GBS library constructed was free of pollution and high quality.Through cluster analysis and principal component analysis,8 regions H.armigera was roughly five subgroups,and subgroup G1 was mainly from Changji and Shache;subgroup G2 was mainly from Aksu;subgroup G3 was mainly from Kashgar,subgroup G4 was mainly from Changji,subgroup G5 was mainly from Shawan.The polymorphism information content（PIC）of the 10 H.armigera populations from0.1721～0.1821,Fst from 0.1156～0.1486,The results showed that there was a wide range of gene exchange among natural population of bollworm in Xinjiang,with low abundance of genetic diversity and medium differentiation.The LD coefficients of linkage imbalance of five subgroups were G5>G2>G4>G1>G3,and the LD attenuation curve of the subgroups was close to parallel to the X axis,and the LD had no obvious attenuation.Seven SNPs were screened from the different genome association analysis of different feeding（Bt cotton and non Bt crops）of H.armigera,and 10 candidate genes were screened on the most significant scaffold062.（2）The UPLC MS/MS method of DIMBOA cloth in H.armigera was established.The method was used to extract the H.armigera samples by Zhangxiaoying and other methods.The detection method had a good linear relationship in the concentration range of 5～100μg/L.LOQ is 5μg/L,and the recovery rate is 84.26%-96.78%at the concentration levels of 5μg/L and 50μg/L.By detecting 711 H.armigera collected from eight locations in Xinjiang,9.85%of them containing DIMBOA.The percentage of H.armigera in which the dineb was detected followed in order Shache（16.90%）>Kashgar（14.00%）>Changji（10.53%）>Aksu（10.00%）>Alaer（9.80%）>Korla（8.00%）>Shawan（6.92%）>Hami（2.00%）.The proportion of maize planting across sites followed the order Shache（17.98%）>Kashgar（14.70%）>Alaer（14.45%）>Changji（12.77%）>Shawan（11.95%）>Aksu（8.20%）>Korla（1.40%）>Hami（1.25%）,Shache and Kashgar maize are planted in high proportions and H.armigera supplied with DIMBOA is also present in high proportions.（3）The single female lines of H.armigera were collected from Korla,Akesu and Zepu and Bt toxin protein was used as artificial feed.In this paper,57,106 and 92 monofemale lines of H.armigera were screened from Korla,Akesu and Zepu,respectively.There was a linear correlation between the average developmental levels of monofemale larvae of H.armigera in normal diet and Cry1Ac diet.The average values of relative developmental levels were 0.5210,0.4935 and 0.4623,respectively.There were no individuals≥0.8,which indicating that the sensitivity of H.armigera population in Zepu was the highest,and the frequency of Bt resistance gene was less than 0.001.Zepu corn planting proportion is higher,which can effectively dilute the Bt resistance gene of H.armigera population.Therefore,Zepu H.armigera population has the highest sensitivity.