关键词: 水稻 （Oryza sativa L.）；根系；根际；细菌群落；16S rRNA基因；qPCR；T\, RFLP

Abstract: In the pot experiment， bacterial 16S rRNA gene was targeted as the molecular biomarker. Quantitative PCR （qPCR） and terminal restriction fragment length polymorphism （T-RFLP） were applied to explore the effects of rice roots on the bacterial community during the rice growing season. Results showed that bacterial abundance in the rhizospheric soil was significantly increased by rice roots， but Shannon diversity index （H′） and evenness index （E） of bacterial community were lower in the rhizosphere than bulk soil. Bacterial community structures were clearly different between rhizosphere and non-rhizosphere soil， dominant bacterial communities appeared with a relatively higher abundance in the rhizosphere soil， while the dominant bacterial communities were different between the flooded and drained treatments. Soil properties in the rhizosphere soil were obviously influenced by the rice roots. Bacterial community structures were closely correlated with soil NH+4-N， TC under the flooded treatment， but with soil pH and moisture under the drained. In summary， growing rice roots could exert significant influence on bacterial abundance and community structures during rice growing season， which could be induced by the variation of soil properties due to rice roots activities. Therefore， rice roots and water status might be important factors affecting bacterial ecological function in paddy fields.

Key words: rice （Oryza sativa L.）, root, rhizosphere, bacterial community, 16S rRNA gene, qPCR, T-RFLP