Effects Of Climate Change On The Population Dynamics Of Rice Planthoppers, Nilaparvata Lugens Sogatella Furcifera And Laodelphax Striatellus Fedding On Transgenic Bt Rice

In recent years, rice production has reduced significantly because of agricultural pests, the promotion and application of Transgenic Bt rice is considered to be fundamental methods to reduce the occurrence and hazards of target pests (lepidopteran pests); but corresponding its also lead to new problem of the increased hazards of Non-target pestssuch as Nilaparvata lugens、Sogatella furcifera and Laodelphax striatellus。 Studies have show that Transgenic Bt rice will change its metabolic physiology with the import of exogenous Bt gene, and then change the secondary metabolites which impact the changes of non-target pest population dynamics。 On the other hand, CO2concentration has increased by100μl/L nearly because of the heavy use of fossil fuels and the change of land utilization, and the tendency will continue to increase in the future。 In the past30years, lot of researches elaborated the impact of ecosystems to the climate change, Elevated of atmospheric CO2concentration is conducive to increase crop photosynthesis and productive green plants photosynthesis, and then improve the productivity under the condition of the improvement of CO2concentration significantly, this will impact the redistribution of the product of plant photosynthesis, for example, its will change the insect-resistant materials’composition and content of plant secondary metabolite. The existing studies have shown that toxin expression amount of transgenic Bt rice will be reduced under conditions of CO2’s elevatant. Obviously, transgenic Bt rice’s insect resistance will change in the elevated CO2environment, and temperature will also affect plant metabolism physiological which will also impact transgenic Bt rice’s insect resistance. Clear that such a comprehensive environmental changes reflect the performance of non-target pest populations will help to play a guiding role in pest control of transgenic Bt rice in the context of global climate change,then serve the ecological sustainable use of transgenic Bt rice,now this regard very little both at home or abroad.In summary, this paper took N. lugens, S. furcifera and L. striatellus which feeding Transgenic Bt Rice Chinese recovery (HH1) and its control Minghui (MH63) as object of study,through field trials and open-top chamber (the Open-Top Chamber; OTC) CO2control experiment, studied the impact of Transgenic Bt rice on non-target pest populations under the conditions of high CO2and different temperature environment systematicly, in order to further discuss the impact of Transgenic Bt rice planting on population dynamics of the non-target pests in the future of elevated atmospheric CO2and global temperature environment. The following is the main results:1、A season-long field experiments were conducted in Xing’an county of Guangxi Province in2010to study the occurrence and damage characteristics of the two unique migratory insects, rice leaffolder, Cnaphalocrocis medinalis, and white-backed planthopper, Sogatella furcifera, feeding on transgenic Bt rice (cv. HHl) with dual crylAb+crylAc genes and its corresponding nontransgenic parent (cv. MH63). Results indicated no significant differences in the abundance of eggs and larvae of C. medinalis, while significant decreases were observed in the damage indexes (i.e., percent of the fold-leaf plants to sampling plants per treatment and fold-leaf rate per plant), regardless of the transgenecity of the host. Thus, there appears to be high target-resistance efficiency for the transgenic Bt rice against C. medinalis. In contrast, there were no significant differences in the population abundance of nymphs or adults (including macro-and brachy-pterous forms) for S. furcifera fed on transgenic Bt rice. However, the nymphs and brachypterous adults fed transgenic Bt rice were markedly larger than those fed on nontransgenic rice during the peak stage for the occurrence of S. furcifera, while the effect on the macropterous individuals was just the opposite. Also, the female:male sex ratio of the macropterous adults on Bt rice was generally lower than that on nontransgenic rice. These results suggested that the resistance of transgenic Bt rice against non-target S. furcifera might becomemore complex in commercial production settings.2、A season-long field experiments were conducted in Ningjing county of Shandong Province in2010to study the occurrence and damage characteristics of the three unique migratory insects, planthopper, Nilaparvata lugens, Sogatella furcifera, Laodelphax striatellus, feeding on transgenic Bt rice (cv. HH1) with dual crylAb+crylAc genes and its corresponding nontransgenic parent (cv. MH63). Results indicated for Nilaparvata lugens and L. striatellus, feeding transgenic Bt rice had no significant effect on its’ turn out. Transgenic Bt rice decrease the population of furcifera significantly. Research the Sub-fin type situation of the adult furcifera population, we found that the Long-winged type adult prefer to feeding the control parental treatment.3、We studied the impact of Doubled CO2concentration (657.7μl/L vs.365.7μl/L)on the Nilaparvata lugens, S. furcifera, L. striatellus. population parameters which take transgenic Bt rice HH1and its control parent MH63for food through the open top chamber,we take this population parameters as object researched systematicly the impact of elevated CO2concentration and temperature changes on occurrence of pest populations and damage when we plant transgenic rice.The results show that:S. furcifera and Nilaparvata lugens are dominant populations, its amount greater than L. striatellus significantly, Elevated CO2concentration promoted the populations of the Nilaparvata lugens and L. Striatellus,but inhibited the number of S. furcifera population significantly. Temperature rise did not effact these three planthopper on a significant level, view from population dynamics, the high temperature had a certain degree of promoting affact on the Nilaparvata lugens nymph,and had a certain degree of inhibition of the adult Nilaparvata lugens. There was a certain degree of promoting affact on S. furcifera nymphs population in the peak of the occurrence of S. furcifera population,and had a certain degree of inhibition of L. Striatellus. Adult Nilaparvata lugens population which take transgetic Bt for food growth reached a significant level. For S. Furcifera, three-factor analysis of variance results and the population occurrence of S. furcifera nymphs all show that S. furcifera nymphs tend to take transgetic Bt rice varieties more, formating significant differences with parents (p=0.049<0.05),while the adult S. furcifera tend to parents MH63more, For L. striatellus no significant differences in population dynamics show that L. striatellus population feeding MH63was more than feeding transgenic Bt rice. Three-factor analysis of variance showed that the change of amount of adult Nilaparvata lugens is not significant neither under the impact of CO2(p=0.774>0.05) or under the impact of temperature single-factor(p=324>0.05), but showed significant increases when high CO2level and high-temperature influenced each other (p=0.037<0.05)...