Study On The Hormesis Induced By Chlorpyrifos In Plutella Xylostella

Hormesis has been proved universality in nature. It has brought about a series of controversies on how to evaluate.Large amounts of pesticides have been produced and applied in the agricultural practices in our country. Organosphosphorus pesticides serve for the production in the agriculture and forest in a long time, which have caused unpleasant in pesticide residues. The problems in pesticide residues have threatened the save of agriculture. Chlorpyrifos occupied an important place in the Organosphosphorus pesticides. It is not presure that the pesticide residues in soil, water and agricultural greenhouses and so on.In this study, chlorpyrifos with 95% content, Plutella xylostella, which was adopted by our lab,was selected as experimental material. Some parameters indicating the toxin in dose effect and high temperature in short-time were determined so as to explore the hormesis induced by chlorpyrifos on Plutella xylostella.These findings wil be hoped to provide some basic data for understanding of the characteristics of hormesis in Plutella xylostella and it will enhanced the understanding of the chlorpyrifos residues in nature.Meanwhile,it will provide a reference for other organosphosphorus pesticides in study on pesticide residues.(1) The 200 μl detection system in automatic microplate reader for determinat--ing the activities of AChE and GSTs in Plutella xylostella was set up, based on the document literature and methods from lab.(2) The susceptibility of S and R of Plutella xylostella to chlorpyrifos was determined.(3) The susceptible strain (S for short), Plutella xylostella,from permanently breeding in glass room and the resistant strain (R for short), Plutella xylostella,from permanently breeding in glass room,which are selected by chlorpyrifos screened from the same commercial vegetable patch in Shangjie town in Fuzhou.With the treatment of acetone, at the first stage,24h pretreatment in Plutella xylostella’s susceptible strain was dealt with by Al in hormesis of S.The second stage,LC10 and high temperature in short-time(25℃、33.5、38℃、40癈)deal with Plutella xylostella’s susceptible strain (4h、8h、12h、18h、24h). At last, determinate the activities of AChE and GSTs. With the treatment of acetone, at the first stage,24h pretreatment in Plutella xylostella’s resistant strain (R) was dealt with by A2 in hormesis of R. At the second stage LCio and high-temperature in short-time(25℃、 33.5℃、38℃、40℃)deal with Plutella xylostella’s resistant strain (R) (4h、8h、12h、 18h、24h). At last, determinate the activities of AChE and GSTs. The results indicated that the activity of AChE both of Plutella xylostella’s susceptible strain and resistant strain (R) in concentration of hormesis were higher than the treatment of acetone after dealt with by LC10.(4) The S and R of Plutella xylostella in the 3rd of the larva was selected as experimental materials.With the treatment of acetone, at the first stage,24h pretreatment in Plutella xylostella’s susceptible strain was dealt with by A1. At the second stage, Plutella xylostella’s susceptible strain was treated with LC50 by 4h、8h、 12h、18h、24h,respectively, at 25℃. At last, determinate the activities of AChE and GSTs. With the treatment of acetone,at the first stage, after 24h pretreatment,Plutella xylostella’s resistant strain (R) was dealt with by A2, the second stage Plutella xylostella’s resistant strain (R) was treated with LC50 by 4h、8h、12h、18h、 24h,respectively, at 25℃. At last, the activities of AChE and GSTs of Plutella xylostella was determinated.The results indicated that the activity of AChE in the of Plutella xylostella’s susceptible strain and resistant strain (R) in concentration of hormesis separately were higher than the treatment of acetone after dealt with by LC50. In addition, obvisiouly,the resistant strain (R) is higer than the susceptible(S) strain in the excited rate of AChE andGSTs activities after dealt with by LC50。...