| The diamondback moth(DBM),P.xylostella(Lepidoptera:Plutellidae),mainly harm cruciferous vegetables,such as radish,cabbage andflowering cabbage etc,is an important crucifer pest.According to statistics,the world's annual investment$4~5 billion for the control of the DBM.Currently,the primary means of control DBM is the use of chemical insecticides,but,because of the people in the use of chemicalinsecticides on the unreasonable,and DBM's generation cycle is short,propagation speed,therefore,the DBM had produce certain resistance to the most chemical insecticides.The use of sex pheromone not only can not kill natural enemies,but also environmentally friendly when using a variety of measures to control DBM,and can achieve a good of control effect.So,whether the DBM is also have resistance to sex pheromone,and if it has resistance,the mechanism of it s resistance is what kind of,the paper has been studied,and the results were as follows:1.Because the proportion and content of sex pheromones in DBM populations in different countries and regions were different,so,the proportion of sex pheromone was tested when the resistance was selected by the use of sex pheromone in the laboratory,in the end,it's concluded that the sex pheromone of the proportion of each component in(Z)-11-hexadecenal:(Z)-11-hexadecyl acetate:(Z)-11-hexadecyl=5:5:1,dosage of55?g,which has the best rate of temptation,the best attractivity rate was 85%.2.Resistant population(R)and susceptible population(S)were obtained after breeding for 12 consecutive generations based on the indoor,and the resistance of the resistant strain to the sex pheromone was 25.83 times,which was moderate Horizontal resistance,the temptation rate also decreased from 85%to 48.9%.Through the construction of life table,the biocompatibility of susceptible and resistant lines was compared,and the biocompatibility of resistant strains was decreased which the relative suitability was 0.768,especially significant differences on the spawning.3.In the study of sex pheromone binding proteins and receptor proteins in the two populations of DBM,the expression of sex pheromone receptor protein by Real-Time quantitative PCR showed that the expression of receptor protein was decreased.,and there was a significant difference with the receptor OR1 corresponding to Z11-16:Ald.The amino acid sequence of the sex pheromone binding protein of the resistant strain has a substitution of amino acids compared to the susceptible strain,in which three pairs of amino acids have been replaced in the PBP3 amino acid sequence.The 60-position arginine was replaced by lysine,the 125-position alanine was replaced with glycine,and the 127-position serine was replaced with threonine.The results showed that the binding free energy between the sex pheromone binding protein and the sex pheromone molecule of the resistant strain could be used to simulate the docking of two sex pheromone receptors PBP3 and three sex pheromone molecules,in which the resistant strain's increased slightly.It is speculated that this phenomenon may be caused by DBM on sexual susceptibility of one of the reasons for the decline.4.The realized heritability(h~2)of the 12 consecutive generations was 0.049.In the early screening period(F0~F5),the heritability was 0.062,which was higher than that of the later stage(F6~F11),and the realized heritability was 0.019.Under the premise of the constant heritability of the resistant population,it's assumed that the algebra required to reduce the susceptibility of the diamondback moth to the sexual attractant by tenfoldlower than that of 50%~90% is about 9.4~4.3. |
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