Aims

Arbuscular mycorrhizal (AM) fungi are intimately associated with fine roots and are involved in nutrient acquisition. However, little information is available on the links between roots of individual orders and fungus colonization and community structure. Our aim was to elucidate AM fungal communities in the fine root systems of the temperate coniferous tree species, Cryptomeria japonica (Cupressaceae).

Methods

We characterized the morphological traits of AM fungi microscopically and determined the community structure of AM fungi using metabarcoding with an Ion Torrent Personal Genome Machine (PGM) focusing on lower-order roots from first to third order roots.

Results

Paris-type and Arum-type AM morphologies were both generally more prevalent on first-order roots than on second- or third-order roots, but the colonization rates by the Paris type were higher than those by the Arum type. We found a total of 48 fungal operational taxonomic units dominated by Glomeraceae, and all the AM taxa detected on third order roots were also found on first and/or second order roots. In the case of the second and third orders, AM fungal communities were affected by soil conditions: electrical conductivity, pH, and N concentration.

Conclusion

These results suggest that the abundance and species richness of AM fungi vary among lower root order systems, and that the AM community is sensitive to soil conditions and turns over as roots age.

中文翻译：

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针叶树 Cryptomeria japonica 丛枝菌根真菌定植现状及群落结构，特别参考根序

宗旨

丛枝菌根 (AM) 真菌与细根密切相关，并参与养分获取。然而，关于单个命令的根与真菌定植和群落结构之间的联系的信息很少。我们的目标是阐明温带针叶树种Cryptomeria japonica（柏科）的细根系统中的 AM 真菌群落。

方法

我们在显微镜下表征了 AM 真菌的形态特征，并使用元条形码和 Ion Torrent Personal Genome Machine (PGM) 确定了 AM 真菌的群落结构，重点是从一阶到三阶根的低阶根。

结果

巴黎型和阿鲁姆型 AM 形态在一级根上普遍高于二级或三级根，但巴黎型和阿鲁姆型的定植率高于阿鲁姆型。我们发现了总共 48 个以 Glomeraceae 为主的真菌操作分类单元，并且在三级根上检测到的所有 AM 分类群也在一级和/或二级根上发现。在二阶和三阶的情况下，AM 真菌群落受土壤条件的影响：电导率、pH 值和 N 浓度。

结论

这些结果表明，AM 真菌的丰度和物种丰富度在较低的根序系统中有所不同，并且 AM 群落对土壤条件很敏感，并随着根年龄的变化而变化。