Mycoheterotrophic plants (MHPs) are leafless, achlorophyllous, and completely dependent on mycorrhizal fungi for their carbon supply. Mycorrhizal symbiosis is a mutualistic association with fungi that is undertaken by the majority of land plants, but mycoheterotrophy represents a breakdown of this mutualism in that plants parasitize fungi. Most MHPs are associated with fungi that are mycorrhizal with autotrophic plants, such as arbuscular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi. Although these MHPs gain carbon via the common mycorrhizal network that links the surrounding autotrophic plants, some mycoheterotrophic lineages are associated with saprotrophic (SAP) fungi, which are free-living and decompose leaf litter and wood materials. Such MHPs are dependent on the forest carbon cycle, which involves the decomposition of wood debris and leaf litter, and have a unique biology and evolutionary history. MHPs associated with SAP fungi (SAP-MHPs) have to date been found only in the Orchidaceae and likely evolved independently at least nine times within that family. Phylogenetically divergent SAP Basidiomycota, mostly Agaricales but also Hymenochaetales, Polyporales, and others, are involved in mycoheterotrophy. The fungal specificity of SAP-MHPs varies from a highly specific association with a single fungal species to a broad range of interactions with multiple fungal orders. Establishment of symbiotic culture systems is indispensable for understanding the mechanisms underlying plant–fungus interactions and the conservation of MHPs. Symbiotic culture systems have been established for many SAP-MHP species as a pure culture of free-living SAP fungi is easier than that of biotrophic AM or ECM fungi. Culturable SAP-MHPs are useful research materials and will contribute to the advancement of plant science.

异养菌植物 (MHP) 无叶、无叶绿素，完全依赖菌根真菌提供碳源。菌根共生是大多数陆生植物与真菌的互惠关系，但菌根异养代表了这种互惠关系的崩溃，因为植物寄生真菌。大多数 MHP 与自养植物菌根真菌有关，例如丛枝菌根 (AM) 或外生菌根 (ECM) 真菌。尽管这些 MHPs 通过连接周围自养植物的常见菌根网络获取碳，但一些异养菌谱系与腐生 (SAP) 真菌相关，后者是自由生活的并分解落叶和木材材料。这种 MHPs 依赖于森林碳循环，其中涉及木屑和落叶的分解，具有独特的生物学和进化史。迄今为止，与 SAP 真菌 (SAP-MHP) 相关的 MHP 仅在兰科植物中发现，并且可能在该科中独立进化了至少九次。系统发育上不同的 SAP 担子菌门，主要是伞菌目，但也有膜壳菌目、多孔菌目等，参与真菌异养。SAP-MHP 的真菌特异性从与单一真菌物种的高度特异性关联到与多种真菌顺序的广泛相互作用不等。共生培养系统的建立对于理解植物-真菌相互作用的机制和 MHPs 的保护是必不可少的。许多 SAP-MHP 物种已经建立了共生培养系统，因为自由生活的 SAP 真菌的纯培养比生物营养 AM 或 ECM 真菌更容易。可培养的 SAP-MHP 是有用的研究材料，将有助于植物科学的进步。