Epiphytism is an example of an obligate interspecific interaction between plants, where a plant species grows on another plant species for physical support. In epiphytic orchids that rely on suitable host tree species (phorophytes) and mycorrhizal fungi for germination and growth, a distinct preference has been observed for particular host tree species. However, the factors driving this host preference remain unclear. In this study, we investigated whether mycorrhizal fungi that promote seedling development determine the preference of phorophytes in the epiphytic orchid Dendrobium wangliangii. First, we identified the preferred host tree species for this orchid. Next, in vitro and in situ germination experiments were conducted to identify potential fungi that promote seed germination. Finally, high‐throughput sequencing was used to assess the distribution of these fungi on both colonized host trees and potential host trees, including individual trees of the host species not yet colonized by the orchid and trees of another species growing in the vicinity of a colonized tree. Dendrobium wangliangii exhibited a preference for trees within the Fagaceae family. Two Fusarium species from the bark of host trees were identified as the primary fungi that promote seed germination. Successful protocorm formation and seedling development were observed exclusively on preferred phorophytes. Fungal community analyses further indicated that both Fusarium spp. occurred on all potential host trees, suggesting that the host preference of this epiphytic orchid is not constrained by the distribution of suitable mycorrhizal fungi. Synthesis: Regarding the epiphytes that depend on mycorrhizal fungi for successful seedling recruitment, we conclude that strong epiphyte–phorophyte associations do not arise from the limited distribution of mycorrhizal fungi but are more likely the result of other factors inherent in the phorophyte environment.

中文翻译：

---

附生兰花（王梁石斛兰）对磷藻的偏好与促进种子萌发的兰花菌根真菌无关

附生现象是植物之间必然的种间相互作用的一个例子，其中一种植物物种生长在另一种植物物种上以获得物理支持。在依靠合适的寄主树种（藻类）和菌根真菌进行发芽和生长的附生兰花中，观察到对特定寄主树种的明显偏好。然而，驱动这种宿主偏好的因素仍不清楚。 在本研究中，我们研究了促进幼苗发育的菌根真菌是否决定了附生兰花中含藻植物的偏好王梁石斛。首先，我们确定了这种兰花的首选寄主树种。接下来，进行体外和原位发芽实验来鉴定促进种子发芽的潜在真菌。最后，使用高通量测序来评估这些真菌在定殖宿主树和潜在宿主树上的分布，包括尚未被兰花定殖的宿主物种的个体树和生长在定殖物附近的另一个物种的树木。树。 王梁石斛对壳斗科 (Fagaceae) 科的树木表现出偏爱。二镰刀菌属来自宿主树皮的物种被确定为促进种子发芽的主要真菌。仅在优选的含藻植物上观察到成功的原球茎形成和幼苗发育。真菌群落分析进一步表明，镰刀菌属种。发生在所有潜在寄主树上，表明这种附生兰花的寄主偏好不受合适菌根真菌分布的限制。 合成：关于依靠菌根真菌成功招募幼苗的附生植物，我们得出的结论是，强的附生植物-叶绿植物关联并不是由菌根真菌的有限分布引起的，而更有可能是叶绿植物环境中固有的其他因素的结果。