Institute of Agricultural Sciences, ETH Zurich, Eschikon 33, 8315, Lindau, Switzerland; Research Institute for Organic Agriculture (FiBL), Ackerstrasse, 5070, Frick, Switzerland.
Mol Ecol. 2014 Feb;23(3):733-46. doi: 10.1111/mec.12625.
Interactions between arbuscular mycorrhizal fungal (AMF) species cocolonizing the same host plant are still little understood in spite of major ecological significance of mycorrhizal symbiosis and widespread occurrence of these fungi in communities rather than alone. Furthermore, shifting the composition of AMF communities has demonstrated consequences for the provision of symbiotic benefits to the host as well as for the qualities of ecosystem services. Therefore, here we addressed the nature and strength of interactions between three different AMF species in all possible two-species combinations on a gradient of inoculation densities. Fungal communities were established in pots with Medicago truncatula plants, and their composition was assessed with taxon-specific real-time PCR markers. Nature of interactions between the fungi was varying from competition to facilitation and was influenced by both the identity and relative abundance of the coinoculated fungi. Plants coinoculated with Claroideoglomus and Rhizophagus grew bigger and contained more phosphorus than with any of these two fungi separately, although these fungi obviously competed for root colonization. On the other hand, plants coinoculated with Gigaspora and Rhizophagus, which facilitated each other's root colonization, grew smaller than with any of these fungi separately. Our results point to as yet little understood complexity of interactions in plant-associated symbiotic fungal communities, which, depending on their composition, can induce significant changes in plant host growth and/or phosphorus acquisition in either direction.
尽管菌根共生具有重要的生态意义，并且这些真菌在群落中广泛存在而不是单独存在，但同一宿主植物上共生活的丛枝菌根真菌（AMF）种间相互作用仍知之甚少。此外，改变 AMF 群落的组成已经证明对宿主提供共生益处以及生态系统服务的质量都有影响。因此，在这里，我们在接种密度梯度上的所有可能的两种真菌组合中，研究了三种不同 AMF 种间的相互作用的性质和强度。在装有紫花苜蓿植物的盆中建立了真菌群落，并使用分类特异性实时 PCR 标记评估了它们的组成。真菌之间的相互作用性质从竞争到促进不等，并且受到共接种真菌的身份和相对丰度的影响。与这两种真菌中的任何一种单独接种相比，与 Claroideoglomus 和 Rhizophagus 共接种的植物生长更大，并且含有更多的磷，尽管这些真菌显然在争夺根定植。另一方面，与 Gigaspra 和 Rhizophagus 共接种的植物相互促进根定植，其生长小于与这两种真菌中的任何一种单独接种的植物。我们的结果表明，植物相关共生真菌群落中的相互作用的复杂性尚未被理解，根据其组成，这可能会导致植物宿主生长和/或磷吸收发生显著变化。
