Host Switching Affects The Fitness And Metabolism Of Myzus Persicae (Sulzer)

Feeding range widely and can transfer damage between different host plants,which caused the uninterrupted and sudden Myzus persicae infestation,it's infestation from the beginning to the outbreak often do not need a very long time.The migration of aphid is one of the important reasons why it is difficult to control,In the face of environmental stress of Myzus persicae will produce alatae,then fly to more suitable environments for their offspring growth and development.Therefore,research on transfer mechanism of aphid to adapt to the host plant in the process,has important significance for the prevention and control of Myzus persicae.We studied the adaptation process from the following three aspects of Myzus persicae:First,the ecological indicators change after peach aphid adapt to a new host plant.We start the research from three parts,the weight difference,the proportion of alatae aphids and the selectivity of two kinds of aphids in the process of pecch adapt to the faba bean aphid.the results show that the aphids from pepper weighed more than the individual have adapted to faba bean;Before adaptation peach aphids has low selectivity to faba bean(far less than the selectivity of pepper),with the time increasing,the selective to faba bean gradually increased;The fitness of peach aphid can be initially concluded by the proportion of alatae.Before 6 generations peach aphid produced more alatae aphids,after the 6 generation Myzus persicae feed on Faba Bean produces few alatae aphids,that means after the 6 generation peach aphid fitness reached a stable level on faba bean.Second,We select several genes in CYP3A4 gene metabolic pathways of peach aphid after it has adapted to faba beans according to transcriptome data,with significant expression of real-time fluorescence quantitative PCR.3 of the selected genes belonging to the cytochrome P450 6family,1 gene belonging to the glutathione S-transferase family and 8 genes belonging to UDP-glucuronosy transferase family,this three genes have an important role in the detoxification of insects.The results show that: there are 9 genes' s expression level have significance differences between peach aphid feed on pepper and faba bean;3 genes' s expression level have no significance differences between aphids feen on pepper an faba bean.We also select two genes CYP6a13 and CYP6a14 doing each generation quantitative,we found that up-regulated gene CYP6a14 was up-regulated in 7 generations,after the 7 generation it basically reached a stable level;and the down-regulation of CYP6a13 was stable after 6 generations,within 6 generations the gene continued downward.This part of results were identical to the proportion of alatae aphids apear regular in the first part.We interferenced CYP6a13 and UGT2B7-3 respectively by injection and leaf absorption,the interference results show that injection interference effect is obviously better than that of absorption leaves in the interference CYP6a13 gene.The interference for UGT2B7-3 are are failed.