上海地区果树根际细菌群落结构的分析

通过PCR—DGGE技术分析上海不同地区六个果园在根瘤病不同发病程度情况下不同树种根际土壤中的细菌群落结构，为根瘤病的防治确定理论依据。样品包括梨树和桃树共计五个品种两种树龄。分析结果表明，不同园区之间果树根际土壤中细菌群落结构差异明显，在DGGE图谱75％相似性上划分，相同园区样品全部聚在同一簇。通过PCA主成分分析可以看出在同一园区中，发病程度不同的土壤样品细菌群落结构差异不显著，而树种对于根际细菌微生态的影响较大，树龄的影响相对较小。

Analysis of the Rhizosphere Bacterial Community Collected from Different Orchards in Shanghai

Using the PCR-DGGE （polymerase chain reaction-denaturing gradient gel electrophoresis） technique, the bacterial community structure was analyzed of the rhizosphere soil collected from six orchards in Shanghai where root nodule caused by Agrobacterium tumefaciens happened in varying degrees. The peach trees of 3 cuhivars and the pear trees of 2 cuhivars were involved, and their ages were ranged from seven to nine years. The analysis results indicated that significant differences in bacterial community structures were found among different gardens. All the samples from the same orchard were divided into the same cluster group, with a similarity of 75%. Based on the results of principal component analysis （PCA）, it is found that insignificant differences in the rhizosphere bacterial community structure were noted among the soil samples with different disease indices in the same orchard, the cultivars had significant effects on the rhizosphere bacterial community structure, but the age of the trees had little effects.