Abstract Morels, fungi from the genus Morchella, are popular edible mushrooms. However, little knowledge of their asexual reproduction and inaccessible pure mitospores hamper illumination of their life cycle. Herein, we successfully induced conidiation, conidial germination and chlamydospore formation in pure culture of Morchella sextelata. Conidiation proceeded via four morphologically distinct stages: development of the conidiophore stalk, stalk branching, phialide differentiation, and conidium production. Terminal and intercalary chlamydospores were formed on conidial hyphae. The development of conidiophores occurred earlier, with more conidia produced, in cross-mating cultures than in single-spore cultures. Mature conidia were spherical and 2.5–8 μm in diameter, with a vast majority (nearly 99%) 2.5–5 μm in diameter. Each conidium contained one to three nuclei (80.2% conidia contained one nucleus, 19.1% contained two nuclei, and 0.7% contained three nuclei). The conidial nucleus diameter was 1–2 μm. The nuclear mitosis in detached conidia that was observed may benefit their colony initiation. Additionally, morel conidia formed conidial anastomosis tubes. Conidia (mitospores) likely not only function as spermatia, but also as reproductive propagules in Morchella. Further research is imperative to elucidate the relationship between the conidia and chlamydospores, and their unique function in the morel life cycle.

中文翻译：

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羊肚菌纯培养中分生孢子、分生孢子萌发和厚壁孢子形成的成功诱导和识别

摘要 羊肚菌属羊肚菌属，是一种广受欢迎的食用菌。然而，对其无性繁殖和难以接近的纯有丝孢子知之甚少，阻碍了对其生命周期的了解。在此，我们成功地在纯培养羊肚菌中诱导分生孢子、分生孢子萌发和厚壁孢子形成。分生孢子通过四个形态上不同的阶段进行：分生孢子梗的发育、茎的分枝、小孢子分化和分生孢子的产生。在分生孢子菌丝上形成终末和居间厚壁孢子。与单孢子培养相比，交叉交配培养中分生孢子梗的发育发生得更早，产生的分生孢子更多。成熟的分生孢子呈球形，直径为 2.5-8 μm，绝大多数（近 99%）直径为 2.5-5 μm。每个分生孢子含有一到三个核（80.2% 分生孢子含有一个核，19.1% 含有两个核，0.7% 含有三个核）。分生孢子核直径为1-2μm。观察到的分离分生孢子中的核有丝分裂可能有利于它们的菌落启动。此外，羊肚菌分生孢子形成分生孢子吻合管。分生孢子（有丝孢子）可能不仅作为精子，而且作为羊肚菌的生殖繁殖体。进一步的研究必须阐明分生孢子和厚壁孢子之间的关系，以及它们在羊肚菌生命周期中的独特功能。此外，羊肚菌分生孢子形成分生孢子吻合管。分生孢子（有丝孢子）可能不仅作为精子，而且作为羊肚菌的生殖繁殖体。进一步的研究必须阐明分生孢子和厚壁孢子之间的关系，以及它们在羊肚菌生命周期中的独特功能。此外，羊肚菌分生孢子形成分生孢子吻合管。分生孢子（有丝孢子）可能不仅作为精子，而且作为羊肚菌的生殖繁殖体。进一步的研究必须阐明分生孢子和厚壁孢子之间的关系，以及它们在羊肚菌生命周期中的独特功能。