The Population Dynamics And Different Expressed Genes Of Mvzus Persicae (Sulzer) On Different Host Plants

In the process of long-term coevolution, the phytophagous insects and plants interact each other. Insect behavior, growth and reproduction are influenced by the nutrients and secondary substances of plants which is adopt by insects through various measures. Meanwhile, host plants the insect choose is directly affected by plant nutrients. The change of the host plants nutrients could cause the corresponding changes of insect material inside and metabolic pathways by which insect adapt to the changed enviroment, including the ecological and physiological and biochemical mechanism.Tobacco is one of the main economic crops in China. However, Myzus persicae (Sulzer) happens rampantly every year, which cause severe damage to the country economy. As polyphagous pest, M. persicae can migrate from one host to another in verse under certain conditions. In a word, M. persicae search for the optimal host plants for reproduction and development. Thus exploring the adaptability of M. persicae on different host plants has the vital significance. In the present study, we investigated the occured dynamic of M.persicae on different host plants in field, the effect of the different host plants on population dynamics of M.persicae using the life tables of laboratory population and further manifested that M. persicae physiological reactions and metabolic changes for adapting to different host plants using Digital Gene Expression Profiling. The corresponding results are as follows:1The dynamic of M. persicae on different host plants in the fieldIn the field M. persicae occur heavily on tobacco, rape. considering the plant growth period, M. persicae occur in rape and before transportion of tobacco, then immigrate to tobacco and Descurainia sophia by generating the alatae after tobacco transportion, especially occur in tobacco. The damage of M. persicae peak in May. That is, The damage of M. persicae peak on rape and Peach in early May. Soon the damage of M. persicae peak on tobacco in mid-May. And the viral disease that M. persicae transmit is more serious in tobacco field. So it is very important to prevention M. persicae in advance. 2The result of the life tables of laboratory populationIn order to define its optimal host plants, based on the life tables of laboratory population, researching the developmental duration, the population survival rate and Life table parameters of M. persicae on tobacco, rape and radish. The results show that there were significant differences in development duration and average daily production quantity of M. persicae on different host plants. With the comprehensive evaluation of the life table parameters, The innate capacity for increase (rm) of M. persicae on different host plants were0.308,0.263,0.243, and the net reproductive rate (R0) were73.433,68.582,67.796, According to the analysis above, so we can get the result that M. persicae like eating tobacco most, the following is Rape, the least is Radish.3Gene differential expression analysis of M. persicae (Sulzer) on different host plantsUsing high-throughput tag-sequencing (tag-sqe) analysis on transcription of M. persicae on different host plants, we received4923781,4762501and4658943, the original sequence tags (raw tags), and the corresponding types of tag number (distinct raw tags)156696,155609and208015respectively. After removing low quality tags (clean tags), all high quality sequencing tags are compared with the reference gene pool.55.21%,55.11%,26.31%tags for the three libraries can be uniquely mapped on the reference sequences, correspondingly16.25%,16.25%and16.25%distinct tags can be positioned on the genome sequence. Gene differential profile analysis found that A total332genes from M.persicae feed on Rape are regulated (192genes up-regulation and140genes down-regulation) compared with that of M.persicae feed on tobacco. A total328genes from M.persicae feed on Radish are regulated (110genes up-regulation and218genes down-regulation) compared with that of M.persicae feed on tobacco. A total225genes from M.persicae feed on Radish are regulated (60genes up-regulation and195genes down-regulation) compared with that of M.persicae feed on Rape. Further real-time PCR analysis found that hsp60gene, CYP gene and FE4gene were significantly regulated, consistent with DGE results.