水葫芦根际细菌群落结构多样性分析

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

摘要:

【目的】了解水葫芦根际细菌群落结构。【方法】运用末端限制性片段长度多态性(Terminal restriction fragment length polymorphism，T-RFLP)技术分析富营养化水体中水葫芦根际和水葫芦近、远水样的细菌群落特征及多样性，结合克隆文库技术和培养法分析根际的细菌种群类型。【结果】同一时期水葫芦根际细菌多样性(Shannon-Weiner指数H′或Simpson指数D)更高，水葫芦近水样次之，远水样最小。10月份的细菌多样性高于5月份的。通过水葫芦根际细菌的克隆文库可知变形杆菌门(Proteobacteria)是水葫芦根际细菌的主要类群，占总群体的65.1%，包括噬菌弧菌(Bacteriovorax sp.)、Dechloromonas sp.、Leptothrix sp.、红螺菌科(Rhodospirillaceae)、Rhodoferax sp.和红环菌科(Rhodocyclaceae)等。T-RFLP图谱显示159 bp为最大优势菌，247 bp为第二大优势菌，对照克隆文库及培养结果分析247 bp属于γ-Proteobacteria，159 bp为不动杆菌(Acinetobacter sp.)。【结论】水葫芦根际细菌的群落结构丰富，不同时段水葫芦根际细菌的丰度略有变化，主要类群为变形杆菌门。

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.