ABSTRACT Many discomycetes show the phenomenon of “puffing”: the quasi-simultaneous discharge of large numbers of ascospores, rendering them visible to the unaided eye as a whiff of smoke above the fruitbody. Obviously, some kind of synchronization mechanism must be present to make all asci involved burst at about the same time. This mechanism has generally been understood to be of a mechanical nature. For a (small, dung-inhabiting) Ascobolus species, puffing was shown to involve a discharge wave propagating radially outward from a random origin at a speed of about 1.5 cm/s. Using high-speed imaging, we have found no evidence for such a wave in puffing by the (much larger, wood-inhabiting) apothecia of Sarcoscypha austriaca. Rather, extended (but limited) areas seem to become active essentially simultaneously, and within these areas a few percent of the asci discharge their spores randomly. In these large fruitbodies, puffing is found to be preceded by a small but distinct deformation of the apothecium, the geometry of which is such that it increases the lateral compressive stress in the hymenium. The observations suggest that this increase in stress is instrumental in causing many asci to burst quasi-simultaneously in the affected area, a hypothesis essentially already proposed by H. Ziegenspeck, about a century ago.

中文翻译：

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Sarcoscypha austriaca 中的“膨化”：回到 Ziegenspeck

摘要 许多盘状菌显示出“膨化”现象：大量子囊孢子准同时排出，使它们在子实体上方的肉眼可见，就像一股烟雾。显然，必须存在某种同步机制才能使所有涉及的 asci 几乎同时突发。这种机制通常被理解为具有机械性质。对于（小型的、栖息在粪便中的）Ascobolus 物种，膨化显示涉及以大约 1.5 cm/s 的速度从随机源径向向外传播的放电波。使用高速成像，我们没有发现这种波是由（更大的，栖息在木头上的）奥地利肉螟的药囊产生的。相反，扩展（但有限）的区域似乎基本上同时变得活跃，在这些区域内，百分之几的 asci 会随机释放它们的孢子。在这些大型子实体中，发现膨化之前是小而明显的果囊变形，其几何形状增加了子膜中的横向压缩应力。观察结果表明，这种压力的增加有助于导致受影响区域的许多腹水准同时爆裂，这一假设基本上已经由 H. Ziegenspeck 在大约一个世纪前提出。