Graduate School of Education, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
Faculty of Education, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
Mycorrhiza. 2020 May;30(2-3):257-268. doi: 10.1007/s00572-020-00945-z. Epub 2020 Mar 13.
We investigated arbuscular mycorrhizal (AM) fungal communities in secondary forests and/or Chamaecyparis obtusa plantations at eight study sites in Japan's temperate region. In the secondary forests, AM plants of the families Lauraceae, Sapindaceae, Rutaceae, Araliaceae, Rosaceae, Magnoliaceae, Cornaceae, Piperaceae, and Anacardiaceae were found. The AM fungal communities were evaluated based on compositions of the AM fungal operational taxonomic units (OTUs), which were clustered at a 97% similarity threshold of the sequences of a partial small subunit of a nuclear ribosomal RNA gene obtained from the plant roots. The compositions of AM fungal OTUs were significantly correlated with the plant family compositions and were significantly differentiated among the study sites and between the study forests. Interestingly, only 19 OTUs remained after selecting for those that had more than 1.0% of the total reads, and these 19 OTUs accounted for 86.3% of the total rarefied reads that were classified into 121 OTUs. Furthermore, three dominant OTUs constituted 48.0% of the total reads, and the most dominant OTU was found at all study sites, except at one. These results indicate that AM fungal communities are primarily constituted by limited AM fungal taxa in the forest ecosystems with diverse plant taxa in Japan's temperate region. The results of basic local algorithm search tool (BLAST) searches against MaarjAM, a database of AM fungal sequences, also revealed that the AM fungi which were the three dominant OTUs are distributed in forest ecosystems on a worldwide scale.
我们调查了日本温带地区八个研究点的次生林和/或柏木人工林的丛枝菌根（AM）真菌群落。在次生林中，发现了樟科、无患子科、芸香科、五加科、蔷薇科、木兰科、山茱萸科、胡椒科和漆树科的 AM 植物。AM 真菌群落是根据 AM 真菌操作分类单元（OTU）的组成来评估的，这些 OTU 是根据从植物根系获得的核核糖体 RNA 基因部分小亚基序列的 97%相似性阈值聚类的。AM 真菌 OTU 的组成与植物科组成显著相关，并在研究点之间以及研究林之间存在显著差异。有趣的是，在选择那些总读取量超过 1.0%的 OTU 后，只剩下 19 个 OTU，而这 19 个 OTU占总共分类为 121 个 OTU 的 86.3%的稀有读取量。此外，三个主要的 OTU 构成了总读取量的 48.0%，除了一个研究点外，所有研究点都发现了最主要的 OTU。这些结果表明，在日本温带地区具有多种植物类群的森林生态系统中，AM 真菌群落主要由有限的 AM 真菌类群组成。对 AM 真菌序列数据库 MaarjAM 进行基本局部算法搜索工具（BLAST）搜索的结果也表明，这三个主要 OTU 的 AM 真菌分布在全球范围内的森林生态系统中。
