Abstract

This study aimed to understand whether the geo-ecological segregation of native plant species affects the root-associated fungal community. Rhizoplane (RP) and rhizosphere (RS) fungal microbiota of Sedum takesimense native to three geographically segregated coastal regions (volcanic ocean islands) were analyzed using culture-independent methods: 568,507 quality sequences, 1399 operational taxonomic units, five phyla, and 181 genera were obtained. Across all regions, significant differences in the phyla distribution and ratio were confirmed. The Chao’s richness value was greater for RS than for RP, and this variance coincided with the number of genera. In contrast, the dominance of specific genera in the RS (Simpson value) was lower than the RP at all sites. The taxonomic identity of most fungal species (95%) closely interacting with the common host plant was different. Meanwhile, a considerable number of RP only residing fungal genera were thought to have close interdependency on their host halophyte. Among these, Metarhizium was the sole genus common to all sites. These suggest that the relationship between potential symbiotic fungi and their host halophyte species evolved with a regional dependency, in the same halophyte species, and of the same natural habitat (volcanic islands); further, the fungal community differenced in distinct geographical regions. Importantly, geographical segregation should be accounted for in national culture collections, based on taxonomical uniqueness.

摘要

本研究旨在了解本地植物物种的地理生态隔离是否影响根相关真菌群落。景天的根际 (RP) 和根际 (RS) 真菌微生物群使用与文化无关的方法对原产于三个地理隔离的沿海地区（火山海洋岛屿）的植物进行了分析：获得了 568,507 个质量序列、1399 个操作分类单元、5 个门和 181 个属。在所有地区，证实了门分布和比率的显着差异。RS 的 Chao 丰富度值大于 RP，并且该方差与属数一致。相比之下，RS 中特定属的优势（辛普森值）低于所有站点的 RP。与共同寄主植物密切相互作用的大多数真菌物种 (95%) 的分类学特征是不同的。同时，相当多的RP只存在于真菌属被认为与其宿主盐生植物具有密切的相互依赖性。其中，绿僵菌是所有站点共有的唯一属。这些表明潜在的共生真菌与其寄主盐生植物物种之间的关系在同一盐生植物物种和相同的自然栖息地（火山岛）中具有区域依赖性；此外，真菌群落在不同的地理区域存在差异。重要的是，基于分类学的独特性，国家文化收藏中应考虑地理隔离。