Abstract: Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and sequence analysis were employed to assess the effects of transgenic Bt maize on the bacterial community structure and phylogeny in rhizosphere soil. In the rhizosphere soils of transgenic maize and its non-transgenic parents, most sequences were characterized by the members of Proteobacteria, Verrucomicrobia, Actinobacteria, Bacteroidetes, Firmicutes, Gemmatimonadetes, and Acidobacteria, among which, Proteobacteria was the dominant group, accounting for 43.5% of the total. The bacterial community structure in the rhizosphere soils of transgenic maize and its non-transgenic parents at different growth stages was highly similar, and had few different bands. Canonical correspondence analysis of the DGGE fingerprints and nutrient contents in rhizosphere soils of transgenic Bt maize and its non-transgenic parents revealed that the bacterial community composition was strongly correlated with soil total nitrogen, total phosphorus, and available nitrogen contents. Principal component analysis showed that the available nutrient contents and bacteria community structure in rhizosphere soils of transgenic Bt maize and its non-transgenic parents were very similar. In sum, there was no evident difference in the bacterial community structure in the rhizosphere soils of transgenic Bt maize planted for one year and of non-transgenic maize.

Key words: Alexandrium tamarense, Prorocentrum donghaiense Lu, Brachionus plicatilis