Abstract: Transgenic maize with insect-resistant gene cry1Ab/cry2Aj and herbicide-tolerant gene G10evo-spsps was planted during the whole growth period. In order to investigate the effect of planting insect-resistant and herbicide-tolerant transgenic maize on rhizospheric microbial communities, quantitative PCR and high-throughput sequencing technologies were employed to analyze the community abundance and composition of bacteria and fungi in maize rhizosphere soils at the jointing and mature stages. The isogenic non-transgenic maize was chosen as the control. Results show that planting transgenic maize had no significant impact on the rhizospheric soil physicochemical properties, fluorescein diacetate hydrolase activity, microbial community abundance and microbial community diversity. At the phylum level, planting transgenic maize significantly increased the relative abundance of rhizospheric Actinobacteria at the jointing and mature stages; at the genus level, planting transgenic maize significantly decreased the relative abundance of rhizospheric Candidatus_Nitrososphaera at the jointing and mature stages. Planting transgenic maize had no impact on fungal taxa at the phylum level, but significantly affected the relative abundance of Fusarium, Staphylotrichum and Lophiostoma at the genus level. In addition, growth stage significantly affected rhizospheric soil dissolved organic carbon and total nitrogen contents; rhizospheric bacterial (rather than fungal community composition and diversity) also affected by growth stage. The findings could provide basic data and theoretical support for the management and control of natural ecological risk of genetically modified crop industrialization.

Key words: stacked traits transgenic crop, rhizosphere environment, high-throughput sequencing, bacteria, fungus, microbial diversity