不同蔬菜连作对土壤细菌DNA分子水平多态性影响的研究

 采用从土壤中直接提取微生物总DNA，并用细菌16S rDNA特异性引物进行PCR扩增、变性梯度凝胶电泳（DGGE）、克隆和测序等一系列分子生物学手段，研究了不同蔬菜连作对土壤中细菌群落结构的影响。结果表明,采自同一地区的土壤样品，其DGGE图谱的相似性很高；同时蔬菜连作对土壤中细菌的群落组成产生影响，这种影响同蔬菜作物种类和连作年限有关。研究结果还表明，所取土样中的细菌大多数为Proteobacteria 类细菌，另外Acidobacteria、Sphingobacteria和Actinobacteria 类细菌只占少量比例。

Effct of Continuous Cropping of Different Vegetables on DNA Polymorphorism of Soil Bacterial

Soil bacterial communities were examined by culture-independent means, namely, 16S rDNA-nested PCR-DGGE profiling. Crude DNA was extracted from soil grown with different vegetables for different years, amplified with bacterial specific primers of 16S rDNA by PCR, and separated by denaturing gradient gel electrophoresis (DGGE). Subsequently, bands on DGGE gels were cloned, sequenced and the resultant information was used to infer the diversity of bacteria in different soils. The results showed that soil samples collected from same area had the high identity in DGGE bands patterns. Bacterial community structure was significantly influenced by continuous cropping system. The effects were closely related to the kind of vegetables and the history of continuous cropping. The sequence results showed that most of the bacteria belong to Proteobacteria; Acidobacteria, Sphingobacteria and Actinobacteria also appeared in the continuously cropped soils.