金沙江石斛是极小种群植物的典型代表，目前已处于濒临灭绝边缘。利用生态专一型促萌发兰科菌根真菌进行种子共生萌发，已成为兰科植物原生地保育的研究热点，但促萌发机制认识的不足限制了其在保护中的应用。前期研究发现，原球茎来源的三种镰刀菌属真菌在实验室内能促进金沙江石斛种子出苗。基于此，本项目拟利用原生境共生萌发鉴定生态专一型促萌发菌根真菌，探索该石斛自然种群回归；利用宏基因组学手段，从促萌发真菌角度揭示其狭域分布格局成因；进而，在原位培养条件下，监测促萌发菌根真菌定位及群落动态变化，发掘其特异诱导的金沙江石斛关键萌发基因；并通过代谢组学及影像质谱联用，揭示二者共生体在化学交流过程中，真菌所产生的促萌发活性分子及其行为，进而阐释共生真菌促萌发机理。本研究解析了金沙江石斛种群分布格局成因及真菌共生萌发机制，为其种群自然回归奠定扎实基础，同时本研究体系也可为兰科植物保育提供重要借鉴。

Dendrobium wangliangii,one of the Plant species with extremely small populations( PSESP), is on the verge of extinction. The symbiotic germination of orchid mycorrhizal fungi in the original habitat is a hot topic in orchid conservation, but the mechanism of promoting germination has not fully been revealed, which limits the application in orchid conservation. Previous studies showed that three Fusarium spp. from protoccorms of Dendrobium wangliangiicould promote the seed emergence of the orchid under laboratory conditions. Based on this observation, eco-specific germination-promoting fungi will be confirmed by symbiotic germination in the original habitat, and then we aim at exploring the field population propagation and regression of the orchid. Secondly, macrogenomics and ex-situ symbiotic germination were used to reveal the origin of the narrow-area distribution pattern of Dendrobium wangliangii from the perspective of eco-specific germination-promoting fungi. Thirdly, the location and dynamic change of community of eco-specific germination-promoting fungi were monitored under in-situ culture conditions. The key germination genes of Dendrobium wangliangii were identified by transcriptome analysis. Metabonomics and MALDI-imaging-MS were used to reveal the germination-promoting active molecules produced by fungi and the orchid during and their behavior in the process of chemical communication. Based upon these investigations, the germination-promoting mechanism of symbiotic fungi would be carefully elucidated. From the perspective of eco-specific germination-promoting fungi, this study analyzes the causes of population distribution pattern of in Dendrobium wangliangii, clarifies the mechanism of symbiotic germination, and then lays a foundation for the conservation of wild population of the Dendrobium. Importantly, the strategy and technology system created in this study provides reference for the orchid conservation.