Stürmer Sidney Luiz, Kemmelmeier Karl, Deveautour Coline, Bentivenga Stephen P, Bever James D
Departamento de Ciências Naturais, Universidade Regional de Blumenau, Blumenau, SC, 89030-903, Brazil.
Institut Polytechnique UniLaSalle, Unité AGHYLE, Mont-Saint- Aignan, Campus Rouen, Normandie, 76130, France.
Mycorrhiza. 2025 Feb 28;35(2):16. doi: 10.1007/s00572-025-01182-y.
Taxonomy of arbuscular mycorrhizal fungi (Glomeromycota) historically has been based mostly on analyses of spore morphology. Molecular evidence has been widely used in phylogeny since the turn of the century and has contributed to the nomenclature of arbuscular mycorrhizal fungi. Considering that some species were described solely from field collected spores which often are degraded, synonymy amongst described species is likely. Type and living cultures of Rhizophagus clarus and Rhizophagus manihotis, and protologue of Glomus zaozhuangianus were analyzed to compare spore wall structure. Sequences of the large subunit (LSU) of the rDNA gene of living isolates of Rhizophagus clarus and Rhizophagus manihotis also were used to test phylogenetic relationships. A comprehensive biogeography of arbuscular mycorrhizal fungi was used to investigate species distribution according to soil and climate factors. Spore wall structure analysis indicates that the three species are morphologically indistinguishable. Spore color, size, and shape all overlap highly among the three species. The spore wall of each is composed of an outer hyaline mucilaginous layer, a rigid hyaline laminated layer conferring a visible "halo" to mature spores, and a third rigid pigmented laminated layer that confers spore color. Phylogenetic analysis shows that living isolates identified as R. manihotis were nested with living isolates of R. clarus, forming a monophyletic clade with 99% bootstrap support. Spores of R. clarus (as amended here) have been recorded in six continents and 31 countries in 10 biogeographical realms. R. clarus was detected most often in soil pH 5.0-6.0, soil P up to 5 mg/dm, and soil organic matter up to 2.5%. Polynomial models indicate that the probability of occurrence of R. clarus is optimized at a temperature of 20 C and 2,000 mm precipitation.
丛枝菌根真菌（球囊菌门）的分类学在历史上主要基于孢子形态分析。自本世纪初以来，分子证据已广泛应用于系统发育研究，并为丛枝菌根真菌的命名做出了贡献。鉴于一些物种仅根据野外采集的往往已降解的孢子进行描述，已描述物种之间可能存在同物异名。对明球囊霉和木薯球囊霉的模式和活体培养物以及枣庄球囊霉的原始描述进行了分析，以比较孢子壁结构。还使用了明球囊霉和木薯球囊霉活体分离株的核糖体DNA基因大亚基（LSU）序列来测试系统发育关系。利用丛枝菌根真菌的综合生物地理学，根据土壤和气候因素研究物种分布。孢子壁结构分析表明，这三个物种在形态上无法区分。这三个物种的孢子颜色、大小和形状高度重叠。每个孢子壁都由一个外部透明粘液层、一个赋予成熟孢子可见“光晕”的刚性透明层状层以及赋予孢子颜色的第三个刚性色素层状层组成。系统发育分析表明，被鉴定为木薯球囊霉的活体分离株与明球囊霉的活体分离株嵌套在一起，形成了一个具有99%自展支持的单系分支。明球囊霉（如本文所修正）的孢子已在六大洲的10个生物地理区域的31个国家被记录。明球囊霉在土壤pH值为5.0 - 6.0、土壤有效磷高达5mg/dm以及土壤有机质高达2.5%的环境中最常被检测到。多项式模型表明，明球囊霉出现的概率在温度为20℃和降水量为2000mm时达到最佳。
