Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia.
Institute of Plant Sciences, University of Bern, Bern, Switzerland.
PLoS One. 2019 Jul 10;14(7):e0219527. doi: 10.1371/journal.pone.0219527. eCollection 2019.
We performed a greenhouse experiment to assess how differences in AM fungal community composition affect competitive response of grassland plant species. We used a full factorial design to determine how inoculation with natural AM fungal communities from different habitats in Western Estonia affects the growth response of two grassland forbs (Leontodon hispidus L., Plantago lanceolata L.) to competition with a dominant grass (Festuca rubra L.). We used AM fungal inocula that were known to differ in AM fungal diversity and composition: more diverse AM fungal communities from open grasslands and less diverse AM fungal communities from former grassland densely overgrown by pines (young pine forest). The presence of AM fungi balanced competition between forb and grass species, by enhancing competitive response of the forbs. The magnitude of this effect was dependent on forb species identity and on the origin of the AM fungal inoculum in the soil. The grassland inoculum enhanced the competitive response of the forb species more effectively than the forest inoculum, but inoculum-specific competitive responses varied according to the habitat preference of the forb species. Our findings provide evidence that composition and diversity of natural AM fungal communities, as well as co-adaptation of plant hosts and AM-fungal communities to local habitat conditions, can determine plant-plant interactions and thus ultimately influence plant community structure in nature.
我们进行了一项温室实验，以评估菌根真菌群落组成的差异如何影响草原植物物种的竞争反应。我们采用完全因子设计来确定来自爱沙尼亚西部不同生境的天然菌根真菌群落的接种如何影响两种草原草本植物（Leontodon hispidus L.，Plantago lanceolata L.）对与优势草（Festuca rubra L.）竞争的生长反应。我们使用了已知在菌根真菌多样性和组成上存在差异的菌根真菌接种物：来自开阔草原的菌根真菌多样性更高，而来自以前被松树过度生长的草原的菌根真菌多样性较低（年轻的松林）。菌根真菌的存在通过增强草本植物的竞争反应，平衡了草本植物和草种之间的竞争。这种效应的大小取决于草本植物的种类和土壤中菌根真菌接种物的起源。草原接种物比森林接种物更有效地增强了草本植物的竞争反应，但接种物特异性的竞争反应根据草本植物的生境偏好而有所不同。我们的研究结果提供了证据表明，天然菌根真菌群落的组成和多样性，以及植物宿主和菌根真菌群落与当地生境条件的共同适应，可能决定植物-植物相互作用，从而最终影响自然界中植物群落的结构。
