Analysis of the diversity of bacterial community structure in the rhizosphere of Eichhornia crassipes

Abstract:

[Objective] To investigate the bacterial community structure in the rhizosphere of Eichhornia crassipes. [Methods] Terminal restriction fragment length polymorphism (T-RFLP) technique was used to analyze the characteristics and diversity of bacterial community in the rhizosphere of E. crassipes and the water samples near and far from it. Clone library technique and culturing method were also used to identify bacteria in the rhizosphere of E. crassipes. [Results] The bacterial community diversity (Shannon-Weiner diversity index H′ or Simpson diversity index D) in the rhizosphere of E. crassipes was the most abundant. The second and the third were that near and far from the rhizosphere of E. crassipes respectively. The bacterial community diversity in October was higher than that in May. According to the clone library of the bacteria in rhizosphere of E. crassipes, the dominant bacteria group was Proteobacteria (65.1%), including Bacteriovorax sp., Dechloromonas sp., Leptothrix sp., Rhodospirillaceae, Rhodoferax sp. and Rhodocyclaceae, etc. T-RFLP profiles revealed that the dominant bacteria was 159 bp, and the second dominant bacteria was 247 bp. 247 bp was identified as γ-Proteobacteria and 159 bp was belonged to Proteobacteria according to the result of the clone library and culture method. [Conclusion] This research indicates that the bacterial community diversity in the rhizosphere of E. crassipes was abundant, and its abundancy changed slightly in different period. The dominant bacterial community in the rhizosphere of E. crassipes was Proteobacteria.