Department of Genetics and Microbiology, Faculty of Bioscience, Autonomous University of Barcelona, Bellaterra, Spain.
Int Microbiol. 2010 Sep;13(3):123-34. doi: 10.2436/20.1501.01.117.
A cultivation-independent approach based on polymerase chain reaction (PCR)-amplified partial small subunit rRNA genes was used to characterize bacterial populations in the surface soil of a commercial pear orchard consisting of different pear cultivars during two consecutive growing seasons. Pyrus communis L. cvs Blanquilla, Conference, and Williams are among the most widely cultivated cultivars in Europe and account for the majority of pear production in Northeastern Spain. To assess the heterogeneity of the community structure in response to environmental variables and tree phenology, bacterial populations were examined using PCR-denaturing gradient gel electrophoresis (DGGE) followed by cluster analysis of the 16S ribosomal DNA profiles by means of the unweighted pair group method with arithmetic means. Similarity analysis of the band patterns failed to identify characteristic fingerprints associated with the pear cultivars. Both environmentally and biologically based principal-component analyses showed that the microbial communities changed significantly throughout the year depending on temperature and, to a lesser extent, on tree phenology and rainfall. Prominent DGGE bands were excised and sequenced to gain insight into the identities of the predominant bacterial populations. Most DGGE band sequences were related to bacterial phyla, such as Bacteroidetes, Cyanobacteria, Acidobacteria, Proteobacteria, Nitrospirae, and Gemmatimonadetes, previously associated with typical agronomic crop environments.
基于聚合酶链反应（PCR）扩增的部分小亚基 rRNA 基因的非培养方法用于表征两个连续生长季节中不同梨品种的商业梨园表土中的细菌种群。梨属植物的梨品种 Blanquilla、Conference 和 Williams 是欧洲种植最广泛的品种之一，占西班牙东北部梨产量的大部分。为了评估社区结构对环境变量和树木物候的异质性，使用 PCR-变性梯度凝胶电泳（DGGE）检查细菌种群，然后通过算术平均值的未加权对组方法对 16S 核糖体 DNA 图谱进行聚类分析。对条带模式的相似性分析未能确定与梨品种相关的特征指纹。基于环境和生物的主成分分析均表明，微生物群落全年根据温度显着变化，在较小程度上受树木物候和降雨的影响。突出的 DGGE 条带被切除并测序，以深入了解主要细菌种群的身份。大多数 DGGE 条带序列与先前与典型农业作物环境相关的细菌门有关，例如拟杆菌门、蓝细菌门、酸杆菌门、变形菌门、硝化螺旋菌门和芽单胞菌门。
