Effects Of Transgenic Hybrid Poplar741on Arthropod Community And Soil Microorganism

In recent years, biosecurity of transgenic plants has attracted much attention. Withthe spread widely of transgenic plants，the study of the potential safety of transgenichybrid poplar741on arthropod community and soil microorganisms become more andmore urgent. In order to study the mechanism and rules of the transgenic poplar onarthropod community structure and characteristics and dynamic fluctuation of arthropodguilds，the arthropod community of transgenic poplar with BtCry3A and BtCry1Ac genewas investigated for two years. And the species and quantities distribution of soilmicroorganisms were studied for two years to each strain of BtCry3A transgenic poplarand BtCry1Ac transgenic poplar in the laboratory. The main results are as follows:1. Effects of transgenic poplar741with BtCry3A and BtCry1Ac gene on arthropodcommunity structureThe two gene transgenic poplar clones had obvious inhibition on herbivorous insect,in2013the number of leaf-eating insects had a decreasing trend compared to in2012. Intransgenic poplar741with BtCry3A and BtCry1Ac test forest, the quantities of suckinginsects of the two gene transgenic poplar741clones were slightly less that of the controlpoplar, but in2013the quantities had increased. The individuals of pest sub-communitywere sharply fewer that of control.The results showed transgenic hybrid poplar741had abetter resistance on pests. The two gene transgenic poplar clones had little effect onpredacitica natural enemy and neutral arthropod. The community structure characteristicindex also proved that transgenic poplar741with BtCry3Ac and transgenic poplar741with BtCry1Ac weres more reasonable than the control on composition structure.2. Effects of transgenic poplar741with BtCry3A and BtCry1Ac on nutritional classes ofarthropod communityCompared to control, the basal species of transgenic poplar741with BtCry3A andBtCry1Ac were almost on difference. The number of Lepidoptera pests was significantlyreduced, the species richness decreased in the following sequence: CK> BtCry3A>BtCry1Ac. The results showed that Lepidoptera pests were restrained by transgenicpoplar741with BtCry1Ac. Compared to control, the richness and individuals of the intermediate species and top species were not difference. The functional groups andquantity were no difference.3. Effects of transgenic poplar741with BtCry3A and BtCry1Ac gene on characteristicindex of arthropod communityThe diversity index and evenness index of the two genes transgenic poplar cloneswere slightly higher than that of control, but the dominant index lower than that ofcontrol, and dynamic trend was consistent. Whether dynamic changes or the generaltrends, the arthropods community stability of transgenic poplar741with BtCry3A andBtCry1Ac were better that of control. Characteristic index of each functional group weresignificantly unlikeness between the two gene transgenic poplar clones, from whole topart, arthropod community had shown well ecological effects, and those index betweentwo genes clones was no significant difference.4. Comprehensive index ranking and clustering analysis of transgenic poplar741withBtCry3A and BtCry1Ac geneCluster analysis showed that three kinds of sample plots could be divided into twoparts. Transgenic poplar741with BtCry1Ac was most similar with control poplar,followed with transgenic hybrid poplar741with BtCry3A. Comprehensive index rankingshowed that the stability of transgenic hybrid poplar741with BtCry3A and BtCry1Acwere better than the control poplar, with a stronger buffering capacity resistanting to theexternal environment.5. Effects of transgenic poplar741with BtCry3A and BtCry1Ac gene on the soilmicroorganismsTransgenic poplar had a significant effect on bacteria, actinomycetes and fungiisolated from soil, and there were significant differences to control. Dynamic trend ofbacteria, actinomyces of each strains were regularity in the rooting zone, rhizospheresoil and root surface： in August the number of bacteria and actinomycetes wassignificantly higher than in other months. There was significant difference to control inthe number of bacteria and actinomycetes, which contained in the rooting zone,rhizosphere soil and root surface in different period. The fungi were isolated from therooting zone, rhizosphere soil, root surface of transgenic clones and non-transgenicclones, while dynamic trend didn’t show the regularity. The number of fungi was morethroughout the growing season, and there were statistically significant difference indifferent months.6. Effects of transgenic poplar741with BtCry3A and BtCry1Ac gene on thecharacteristics index soil fungal communitiesFrom the general trend, the specises of fungi contained in the rooting zone weremore than in the root surface soil. The diversity index and evenness index in the rootingzone of transgenic poplar741with BtCry3A were higher than that of control, but the dominant index lower than that of control. The diversity index and evenness index in therhizosphere soil and the root surface soil of the two genes of transgenic poplar741werehigher, the dominant index lower than that of the control. So two genes of transgenicpoplar741fungi communities showed the better stability.