Establishment and application of the PASA technique of resistance detection to bifenthrin resistance in Tetranychus urticae Koch(Acari: Tetranychidae)
Author of the article:WANG Ling** ZHANG You-Jun WU Qing-Jun XIE Wen WANG Shao-Li***
Author's Workplace：Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Key Words： Tetranychus urticae, bifenthrin, insecticide resistance, PCR amplification of specific alleles
Abstract：[Objectives] The two spotted spider mite, Tetranychus urticae Koch, is an important agricultural pest. Pesticide resistance seriously impairs the ability to control this pest. We developed a PCR amplification of specific alleles (PASA) technique in order to detect resistance of T. urticae to pyrethroids. [Methods] The toxicities of bifenthrin to different T. urticae populations were determined using the slide-dip method. The DNA fragment in IIIS6 of the para-type sodium channel protein of T. urticae was cloned. A PASA technique was developed based on the point mutation of F1538I and was used to measure the point mutation frequencies of different T. urticae populations. [Results] Compared to a relatively susceptible strain, field populations collected from Tongxian, Beijing and Sanya, Hainan exhibited resistance to bifenthrin with the LC50 values of 1 982.6 mg/L and 2 767.4 mg/L, which are 6.0- and 8.4-fold respectively, higher than that of the susceptible strain. PASA genotyping results indicate that the F1538I mutation frequency was 10.0% in heterozygotes in the susceptible strain, whereas mutation frequencies as high as 50.0% and 53.3% were found in the Beijing and Hainan populations, respectively. [Conclusion] The PASA technique can be used to detect gene mutations in wild populations of T. urticae that are indicative of resistance to bifenthrin.