Morpho-anatomical differences among mycoheterotrophic Afrothismia spp. (Thismiaceae) indicate an evolutionary progression towards improved mycorrhizal benefit
Bibliographic record
Abstract
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.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.022 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".