Wang Yong-Long, Zhang Xuan, Xu Ying, Babalola Busayo Joshua, Xiang Si-Min, Zhao Yan-Ling, Fan Yong-Jun
Faculty of Biological Science and Technology, Baotou Teacher's College, Baotou, China.
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Front Microbiol. 2021 Mar 16;12:646821. doi: 10.3389/fmicb.2021.646821. eCollection 2021.
Ectomycorrhizal (EM) fungi play vital roles in ensuring host plants' health, plant diversity, and the functionality of the ecosystem. However, EM fungal diversity, community composition, and underlying assembly processes in Inner Mongolia, China, where forests are typically semiarid and cold-temperate zones, attract less attention. In this study, we investigated EM fungal communities from 63 root samples of five common pine plants in Inner Mongolia across 1,900 km using Illumina Miseq sequencing of the fungal internal transcribed spacer 2 region. We evaluated the impact of host plant phylogeny, soil, climatic, and spatial variables on EM fungal diversity and community turnover. Deterministic vs. stochastic processes for EM fungal community assembly were quantified using β-nearest taxon index scores. In total, we identified 288 EM fungal operational taxonomic units (OTUs) belonging to 31 lineages, of which the most abundant lineages were , , , and . Variations in EM fungal OTU richness and community composition were significantly predicted by host phylogeny, soil (total nitrogen, phosphorus, nitrogen-phosphorus ratio, and magnesium), climate, and spatial distance, with the host plant being the most important factor. β-nearest taxon index demonstrated that both deterministic and stochastic processes jointly determined the community assembly of EM fungi, with the predominance of stochastic processes. At the Saihanwula site selected for preference analysis, all plant species (100%) presented significant preferences for EM fungi, 54% of abundant EM fungal OTUs showed significant preferences for host plants, and 26% of pairs of plant species and abundant fungal OTUs exhibited remarkably strong preferences. Overall, we inferred that the high diversity and distinctive community composition of EM fungi associated with natural pine species in Inner Mongolia and the stochastic processes prevailed in determining the community assembly of EM fungi. Our study shed light on the diversity and community assembly of EM fungi associated with common pine species in semiarid and cold temperate forests in Inner Mongolia, China, for the first time and provided a better understanding of the ecological processes underlying the community assembly of mutualistic fungi.
外生菌根（EM）真菌在确保宿主植物健康、植物多样性和生态系统功能方面发挥着至关重要的作用。然而，在中国内蒙古地区，森林通常处于半干旱和寒温带，该地区的EM真菌多样性、群落组成及潜在的组装过程较少受到关注。在本研究中，我们使用真菌内转录间隔区2区域的Illumina Miseq测序技术，对内蒙古1900公里范围内五种常见松树植物的63个根系样本中的EM真菌群落进行了调查。我们评估了宿主植物系统发育、土壤、气候和空间变量对EM真菌多样性和群落周转的影响。使用β-最近分类单元指数得分对EM真菌群落组装的确定性与随机性过程进行了量化。我们总共鉴定出288个属于31个谱系的EM真菌操作分类单元（OTU），其中最丰富的谱系是 、 、 和 。宿主系统发育、土壤（总氮、磷、氮磷比和镁）、气候和空间距离显著预测了EM真菌OTU丰富度和群落组成的变化，其中宿主植物是最重要的因素。β-最近分类单元指数表明，确定性和随机性过程共同决定了EM真菌的群落组装，且随机性过程占主导地位。在选择用于偏好分析的赛罕乌拉站点，所有植物物种（100%）对EM真菌均表现出显著偏好，54%的丰富EM真菌OTU对宿主植物表现出显著偏好，26%的植物物种与丰富真菌OTU对表现出极强的偏好。总体而言，我们推断内蒙古天然松树物种相关的EM真菌具有高多样性和独特的群落组成，且随机性过程在决定EM真菌群落组装中占主导地位。我们的研究首次揭示了中国内蒙古半干旱和寒温带森林中与常见松树物种相关的EM真菌的多样性和群落组装情况，并更好地理解了共生真菌群落组装背后的生态过程。
