Systematic revision of the <i>Tubifera casparyi–T</i>. <i>dictyoderma</i> complex: Resurrection of the genus <i>Siphoptychium</i> and introduction of the new genus <i>Thecotubifera</i>

The genus <i>Siphoptychium</i> is resurrected on the basis of comparative morphology and phylogeny of partial nuc 18S rDNA (18S) and translation elongation factor 1-alpha (<i>EF1A</i>) nucleotide sequences. The genus is characterized by the firm upper surface of the pseudoaethalium, accreted but easily separable sporothecae, a tubular or fibrous columella, and spores with a reticulate ornamentation consisting of 7–9 meshes across the diameter. In addition to the currently known single species <i>S. casparyi</i> (= <i>Tubifera casparyi</i>), two new members of <i>Siphoptychium</i> are described: <i>S. violaceum</i> from coniferous forests of Europe, east Asia, and southeast Asia, and <i>S. reticulatum</i> from temperate and subarctic regions of North America and alpine regions of Europe. A second genus, <i>Thecotubifera</i>, is described to accommodate <i>Tubifera dictyoderma</i>. The fruiting body of this species is transitional between a pseudoaethalium and a true aethalium. It is covered by a contiguous membranous cortex formed by the fused tips of the sporothecae, a feature typical for aethalia. However, the inner portions of sporothecae remain discernible, a feature more typical for pseudoaethalia. Columellae of <i>Th. dictyoderma</i> are formed by perforated plates, and the spores have a reticulate ornamentation consisting of 2–5 meshes across the diameter. For <i>Th. dictyoderma</i>, we could confirm records only for tropical regions and Japan, whereas all studied European specimens, including those mentioned in current monographs, represent species of <i>Siphoptychium</i>.本研究通过比较形态学分析及针对部分核18S核糖体DNA（18S）与翻译延伸因子1-α（EF1A）核苷酸序列的系统发育研究，恢复了Siphoptychium属的有效分类地位。该属的鉴别特征为：假复囊体的上表面坚实；孢囊聚生但易于分离；囊轴呈管状或纤维状；孢子具网状纹饰，每直径方向上的网孔数为7~9个。除当前已知的单一物种S. casparyi（异名为Tubifera casparyi）外，本研究还描述了Siphoptychium属的2个新成员：分别为采自欧洲、东亚及东南亚针叶林的S. violaceum，以及采自北美洲温带与亚北极地区及欧洲阿尔卑斯山区的S. reticulatum。此外，本研究还建立了新属Thecotubifera，以容纳Tubifera dictyoderma。该物种的子实体处于假复囊体与真复囊体的过渡类型：其表面被一层由孢囊顶端融合形成的连续膜状皮层所包裹，这一特征是真复囊体的典型特征；但孢囊的内部结构仍可分辨，这一特征更符合假复囊体的特点。Th. dictyoderma的囊轴由穿孔板构成，其孢子具网状纹饰，每直径方向上的网孔数为2~5个。本研究仅在热带地区及日本确认了Th. dictyoderma的分布记录，而所有已研究的欧洲标本（包括当前分类专著中提及的标本）均隶属于Siphoptychium属物种。

搜集汇总

背景与挑战

背景概述

该数据集基于形态学和分子系统发育分析，对粘菌中的Tubifera casparyi–T. dictyoderma复合体进行了系统修订。它恢复了Siphoptychium属（包括三个物种，描述其子实体结构和孢子特征），并引入了新属Thecotubifera以容纳Tubifera dictyoderma，重点阐述了其过渡性子实体形态和地理分布。