Hempel Stefan, Renker Carsten, Buscot François
Terrestrial Ecology, Institute of Biology I, University of Leipzig, Johannisallee 21-23, D-04103 Leipzig, Germany.
Environ Microbiol. 2007 Aug;9(8):1930-8. doi: 10.1111/j.1462-2920.2007.01309.x.
Most studies on the species composition of arbuscular mycorrhizal fungi (AMF) have solely analysed mycorrhizal roots or AM spores collected from soil samples. However, the spore production rate and proportions of AMF mycelium in roots and soils have all been shown to vary substantially in a taxon-specific manner. Therefore, in the study presented here we used a molecular approach to analyse the species composition of AMF in spores, intra-radical and extra-radical mycelium in an intensively farmed meadow in central Germany. By polymerase chain reaction and sequencing of the ITS region members of seven different families and species groups within Glomeromycota were identified. The data revealed remarkable differences in the composition of AMF taxa both between the spores and the mycelia, and between the two types of mycelia. Glomus group Ab was dominant in roots and spores, in accordance with previous research. However, members of this group were rarely detected as extra-radical mycelium, in which Paraglomeraceae were dominant, although we found no evidence for the presence of Paraglomeraceae in roots or spores, even when a specific primer set was used. These results may be interpreted as a further indication that AMF are not necessarily obligate symbionts of plants.
大多数关于丛枝菌根真菌（AMF）物种组成的研究仅分析了从土壤样本中采集的菌根根或AM孢子。然而，AMF的孢子产生率以及在根和土壤中的菌丝体比例均已表明会以特定分类群的方式大幅变化。因此，在本文所呈现的研究中，我们采用分子方法分析了德国中部一块集约化种植草甸中孢子、根内和根外菌丝体中AMF的物种组成。通过聚合酶链反应和对ITS区域进行测序，鉴定出了球囊菌门内七个不同科和物种组的成员。数据显示，AMF分类群的组成在孢子与菌丝体之间以及两种类型的菌丝体之间均存在显著差异。与先前的研究一致，Glomus组Ab在根和孢子中占主导地位。然而，该组的成员在根外菌丝体中很少被检测到，根外菌丝体中Paraglomeraceae占主导地位，尽管即使使用了特定的引物组，我们也未在根或孢子中发现Paraglomeraceae存在的证据。这些结果可能被解释为进一步表明AMF不一定是植物的专性共生体。
