Premise Pyrophilous fungi form aboveground fruiting structures (ascocarps) following wildfires, but their ecology, natural history, and life cycles in the absence of wildfires are largely unknown. Sphaerosporella is considered to be pyrophilous. This study explores Sphaerosporella ascocarp appearance following a rare 2016 wildfire in the Great Smoky Mountains National Park (GSMNP), compares the timing of ascocarp formation with recovery of Sphaerosporella DNA sequences in soils, and explores the association of Sphaerosporella with post‐fire Table Mountain pine (Pinus pungens) seedlings. Methods Burned sites in the GSMNP were surveyed for pyrophilous fungal ascocarps over 2 years. Ascocarps, mycorrhizae, and endophyte cultures were evaluated morphologically and by Sanger sequencing of the nuclear ribosomal ITS gene region (fungal barcode; Schoch et al., 2012). DNA from soil cores was subjected to Illumina sequencing. Results The timing and location of post‐fire Sphaerosporella ascocarp formation was correlated with recovery of Sphaerosporella DNA sequences in soils. Genetic markers (fungal barcode) of Sphaerosporella were also recovered from mycorrhizal root tips and endophyte cultures from seedlings of Pinus pungens. Conclusions This study demonstrates that Sphaerosporella species, in the absence of fire, are biotrophic, forming both mycorrhizal and endophytic associations with developing Pinus pungens seedlings and may persist in nature in the absence of wildfire as a conifer symbiont. We speculate that Sphaerosporella may fruit only after the host plant is damaged or destroyed and that after wildfires, deep roots, needle endophytes, or heat‐resistant spores could serve as a source of soil mycelium.

中文翻译：

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球孢子菌属嗜热真菌的秘密生活方式

前提 嗜火真菌在野火后形成地上果实结构（囊果壳），但在没有野火的情况下，它们的生态、自然历史和生命周期在很大程度上是未知的。球孢子菌被认为是嗜火的。本研究探讨了 2016 年大烟山国家公园 (GSMNP) 发生罕见野火后球孢子菌子囊果的外观，比较了子囊果形成时间与土壤中球孢子菌 DNA 序列的恢复，并探讨了球孢子菌与火灾后桌山松树的关联(Pinus pungens) 幼苗。方法 对 GSMNP 中燃烧的部位进行了为期 2 年的嗜火真菌子囊果皮调查。囊果、菌根和内生菌培养物通过形态学和核核糖体 ITS 基因区域的 Sanger 测序（真菌条码；Schoch 等人，2012 年）。来自土壤核心的 DNA 进行了 Illumina 测序。结果 火灾后球孢子菌子囊果皮形成的时间和位置与土壤中球孢子菌 DNA 序列的恢复相关。Sphaerosporella 的遗传标记（真菌条码）也从红松幼苗的菌根根尖和内生菌培养物中回收。结论 本研究表明，在没有火的情况下，球孢菌属物种是生物营养的，与正在发育的红松幼苗形成菌根和内生关联，并且可以在没有野火的情况下作为针叶树共生体在自然界中持续存在。我们推测 Sphaerosporella 可能只有在宿主植物被破坏或破坏后才能结果，并且在野火、深根、针状内生菌、