Abstract: Roundup ready transgenic soybean [Glycine max (L.) Merr.] (RRS) is one of the genetically modified crops and firstly commercialized by the Monsanto Company. In recent years, more attention has been paid on the risk assessment of RRS, including the potential effects on soil biota diversity. Ammoniaoxidizing archaea (AOA) are a group of the key microbes in nitrification, playing an important role in N cycle. By using PCR-DGGE cloning, this paper studied the diversity of AOA communities in the rhizosphere soils of RRS, its non-transgenic parental isoline (RRS-S), wild soybean (W-S), and cultivated soybean (D-46), aimed to provide theoretical basis for the ecological safety assessment on the transgenic soybean. The RRS had no remarkable effects on the AOA diversity, based on the Shannon diversity index and evenness index. The principal components analysis and DGGE analysis showed that the AOA community structure in the rhizosphere of RRS was significantly different with that in the rhizosphere of WS and D-46, but had no significant difference with that in the rhizosphere of RRS-S. Moreover, the AOA amoA gene sequencing of DGGE bands and the phylogenetic analysis revealed that parts of the AOA in the rhizosphere of test soybean cultivars belonged to the clusters already reported in soil/sediment, others belonged to the unknown clusters or groups in soil, but none of them belonged to the clusters in water or sediment. There was little change in the DGGE bands, among which, bands 1, 20, and 25 were missing, and band 3 was specific for RRS. In conclusion, RRS had no apparent effect on the diversity of AOA in rhizosphere soils, but could alter the composition of AOA community.

Key words: Quercus aquifolioides, point pattern analysis, distribution pattern, spatial association.