Achlorophyllous, mycoheterotrophic plants depend on their mycorrhizal fungi for 100% of their carbon supply. Hence, there is strong evolutionary pressure towards a well-organized functioning of the association from the plant’s perspective. Members of the mycoheterotrophic genus Afrothismia have evolved elaborate fungal colonization patterns allowing a sustained benefit from external fungal penetration events. On the basis of anatomical details of the root-shoot systems of A. korupensis and A. hydra, we elucidate an evolutionary progression between the comparatively simple mycorrhizal pattern in A. gesnerioides and the so far most complex mycorrhiza in A. saingei. We detected two major advancements: (1) two species, A. korupensis and A. saingei, use the fungus itself as energy storage, replacing starch depositions used by A. gesnerioides and A. hydra, and (2) the morphological complexity of hyphal forms in plant tissue compartments increases from A. gesnerioides to A. saingei. We discuss the omitting of starch metabolism as well as the morpho-anatomical differences as an evolutionary fine-tuning of the compartmented mycorrhizal organization in Afrothismia. Our results support the idea of a taxonomic distinction between Afrothismia and other Thismiaceae.

中文翻译：

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异肌营养不良性非洲人种之间的形态解剖学差异。（蓟科）表明向改善的菌根有益性的进化进展。

绿藻类，异养真菌的植物100％的碳供应依赖于其菌根真菌。因此，从植物的角度来看，对组织的组织功能有很大的进化压力。真菌异养型非洲失语属的成员已经进化出精细的真菌定植模式，从而可以从外部真菌渗透事件中持续受益。根据A的根冠系统的解剖细节。korupensis和一个。hydra，我们阐明了相对较简单的gernerioides菌根模式与迄今为止最复杂的a。saingei菌根之间的进化进程。。我们检测到两个主要进展：（1）两个物种，A。korupensis和A. saingei，使用真菌本身作为能量存储，替代了A. gesnerioides和A. hydra使用的淀粉沉积，以及（2）菌丝的形态复杂性植物组织区室中的形式从gersnerioides到a。saingei增加。我们讨论了省略淀粉代谢以及形态-解剖学差异，作为对非洲痴呆症的分隔性菌根组织进行进化的微调。我们的结果支持非洲菊苣和其他菊科之间的分类学区分。