Nitrogen-mediated Effects Of Transgenic CrylAb Rice On A Population Of Nilaparvata Lugens (St(?)l)

The application of nitrogen fertilizer can improve the nutritional status of rice,and it can promote the continuous and stable expression of Bt crystal protein in transgenic rice.On the other hand,excessive application of nitrogen fertilizer can also lead to leggy rice plants,reduce rice yield,and increase the incidence of rice pests and diseases.The risk may be that the resistance to nontarget pests may be reduced on transgenic insect-resistant rice,which will benefit nontarget pest populations.In this paper,transgenic crylAb rice and its parental nontransgenic rice were used as experimental materials and grown under controlled conditions in artificial climate chambers to investigate the effects of nitrogen-mediated transfer of crylAb rice on a population of the nontarget pest:the brown planthopper.The main findings are as follows:Rice varieties had less effect on amino acid content in rice stems under low nitrogen and normal nitrogen levels,and had greater influence on amino acid content in rice stems under high nitrogen conditions.There was significant difference in amino acid content in rice varieties with different nitrogen levels.The results showed a tendency that high nitrogen promoted amino acid expression in rice stems,and only a few amino acids declined.Feeding selectivity studies found that the feeding of adults of the brown planthopper(Nilaparvata lugens)was promoted by a high nitrogen level.However,there was no significant difference in the feeding selectivity of the brown planthopper between the crylAb rice and the nontransgenic rice at the same nitrogen level.After 12,48,and 72 h,the nymphs of N.lugens fed on the crylAb rice were significantly more abundant than were the N.lugens nymphs fed on nontransgenic rice treated with low nitrogen and normal nitrogen.The oviposition selectivity study found that there was no significant difference in the fecundity of brown planthopper between transgenic crylAb rice and non-transgenic rice in the same nitrogen level.In the non-transgenic rice,the fecundity of the brown planthopper was significantly different between the three nitrogen levels.In the transgenic crylAb rice,the difference in the fecundity of the brown planthopper between the low nitrogen and normal nitrogen levels was not significant,while the fecundity under the high nitrogen was significantly higher than those under the other two nitrogen levels.In each nitrogen level,the life table of a two-sex population was found for the brown planthoppers with long-term feeding on non-genetically modified rice(CC),short-term feeding on crylAb rice(CT)and long-term feeding on crylAb rice(TT).The intrinsic,weekly and net value added rates were not significantly different,but to a certain extent,the average generation period of the CT and TT strains was prolonged,and that of the CT strain was significantly prolonged in both the low and normal nitrogen treatments.The average generation period of the TT strain was significantly longer than that of the CC strain in the normal nitrogen treatment.The low nitrogen treatment significantly reduced the intrinsic rate of growth and the weekly growth rate of the CT strain,significantly prolonging the average generation cycle,while the low nitrogen and high nitrogen treatment had no significant effect on the dynamic parameters of the life table of the TT strain.In summary,nitrogen rates had certain effects on the growth and development,life history parameters,feeding and oviposition behavior of the brown planthopper,however,the transgenic crylAb rice had no significant effect on the growth and development,life history parameters,feeding and oviposition behavior of the brown planthopper mediated by nitrogen.