For the very first time, morpho-anatomical features of both fruiting bodies as well as below-ground structures have been confronted with a newly produced multigene phylogeny of root symbiotic basidiomycetes using one of the most speciose genera of ectomycorrhizal fungi (Russula, Russulales) as an example. In this first of two papers, the authors focus more specifically on below-ground structures. Our five-gene phylogeny divides the genus in five main clades, here interpreted as representing seven subgenera, all significantly supported. Although more conserved than features of fruiting bodies, the anatomy of ectomycorrhiza does not allow for an unambiguous characterization of the main clades resolved by phylogenetic analysis, but the anatomy of ectomycorrhiza performs better to naturally classify the species of this genus. Features of fruiting bodies remain much more adequate for the delimitation of terminal clades and are irreplaceable for morphological species identification. Tropical taxa mostly nest in ancient lineages, but are also present in some terminal clades of otherwise temperate species groups. The shift from plectenchymatic to pseudoparenchymatic ECM outer mantle structures happened most likely already in the paleotropics, and is here hypothesized to have facilitated a major diversification of the genus with new hosts in the northern hemisphere. Available data as well as our own observations on below ground structures of several Lactifluus species suggests that this genus shares with Russula the absence of lactifers in ECM mantles and rhizomorphs, contrary to species of Lactarius where lactifers are always present. First observations on rhizomorphs of species in Multifurca confirm the presence of vessel-like and ladder-like hyphae, also found in the other agarioid genera of this family, while distinct lactifers are only present in the lactarioid, but not in russuloid members of this genus.

中文翻译：

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走细线…十年后：地上和地下特征的困境，以支持俄罗斯菊科（Basidiomycota）的系统发育

第一次，子实体和地下结构的形态解剖学特征都面临着使用最外生菌根真菌（Russula）最特殊属之一的根生共生担子菌的多基因系统发育的新问题。，例如Russulales）。在这两篇论文的第一篇中，作者更具体地关注地下结构。我们的五基因进化史将属划分为五个主要进化枝，在这里被解释为代表七个亚属，所有这些都得到了大力支持。尽管比子实体的特征更为保守，但外生菌根的解剖结构无法对通过进化系统分析所解析的主要进化枝进行明确的表征，但是外生菌根的解剖结构表现得更好，可以自然地对该属的物种进行分类。子实体的特征对于限定末端进化枝仍然更加合适，并且在形态学物种鉴定中是不可替代的。热带分类单元大多筑巢于古代血统，但也存在于其他温带物种种群的终末进化枝中。ECM外地幔结构从早动性转变为准早性外地幔结构很可能已经发生在古气候中，并且据推测，这促使北半球有了新的寄主，使该属大大多样化。可用数据以及我们对以下几种地下结构的观察Lactifluus物种表明，该属与Russula一样，在ECM地幔和根茎中不存在催乳素，这与Lactarius始终存在催乳素的物种相反。首次对Multifurca中物种的根茎形态进行观察证实，在该家族的其他琼脂类属中也发现了血管状和梯状菌丝的存在，而不同的泌乳素仅存在于乳类动物中，而在该属的类瘤状体中不存在。 。