Ecological Safety Assessment Of Transgenic Hybrid Poplar 741 With Two Insect-resistant Genes On Arthropod Community

The biological security problem has already been one of the main factorswhich hinder the extensive aPplying oftransgenic insect-resistant plants. In order to quest the contents and methods of the assessment of the arthropod community security affected by the transgenic insect-resistani plants, the possible ecological risks on arthropodcommunity, which were imposed by the transgenic insect-resistant plants after it's releasing into the environment, and the regulation and mechanism of the mutual influencebetween plants and arthropod were aPpraised through field system investigation. Thedifferent stands of high insect-resistance hybrid poplar 741(Pb11, Pb29, Pb3) andmedium insect-resistance hybrid poplar 741(Pb17, Pb1) were used as plant materials, soas to provide the scientific foundations to the persisting rational application of theinsect-resistance hybrid poplar 741, the resultS are as follows:(1) Impacts of transgenic insectresistant hybrid poplar 741 on arthropod communitystructureThe abundance of arthropod community of transgenic insect-resistant hybrid poplar741 significantly increased, but the individuals obviously decreased, the communitystructure are more reasonable; species and individuals of natUral enemy all increased, thenumber of pest decreased, individuals of neutral Arthropod increased. there were obviousvariance among the Arthropod community structure feature indices of different hybridpoplar 741. Not only from the dynamic changes to the total trends but also from whole topart, there were bet-ter ecological effect on the arthropod communities in high andmedium insect-resistance hybrid poplar 741 stands. So, transgenic insect-resistant hybridpoplar 741 has no obvious1y negative effect on arthropod community structure.(2) Impacts of transgenic insect-resistant hybrid poplar 741 on nutritional classes andvertical structure of arthropod communitySpecies richness of pests was obviously low in basal species of transgenicinsect-resistant hybrid poplar 741, neutfal Arthropod increased, the individuals ofifltermediate species and top species aPparently increased. In arihropod community, thesuperiority of phytophagous dominan functional groups was higher or lower than that ofCK, and the superiority of predator and parasitoids ascended. Arthropod community intrees and soil was better than CK in delamination of space. Arthropod community in grassand ground was similar to CK. So, transgenic insect-resistant hybrid poplar 741 showedpositive effect on nutritiona1 classes and vertical structure of arthropod community.(3) Impacts of transgenic insect-resistant hybrid poplar 741 on pests and natural enemiespopulation dynamicsIn the time ordef, the transgenic insectresistam hybrid poplar 741 displnyedresistallce on target pests, it's number was aPparently decreased. There was no obviousdifference between high and medium insect-resistance hybrid poplar 741 stands; thetransgenic insectresistant hybrid pop1ar 741 had some effect on non-eqet pests.Comparing the arthropod community in the transgenic insect-resistam hybrid poplar 741stands with that in ck stands, leaf eating insect increased a little, sap-sucking insectmarkedly decreased; predatOrs increased greatly and had little relation to pest, butparasitoids had a little decrease. Transgenic insect-resistan hybrid poplar 741 hasnegative effect on target and non4arget pests, but have positive effect on natUral enemiesand neutral Arthropod.(4) Ecological niche variation of arthropod community in transgenic insect-resistalhybrid poplar 741 standsThe spatial niche breadth of target pests was least, the niche breadths of otherfunctional groups were wide. Predators and parasitoids have a narrower niche overlapwith the target pest, but have a wider niche overlaP with the neutral species. There aresevere competition among pests and between predators and parasitoids. The transgenicinsect-resistant hybrid poplar 741 has a positive effec...