Spatial separation of mycobionts in the giant, differentiated root system of <i>Cyrtosia septentrionalis</i>, a fully myco-heterotrophic orchid
Bibliographic record
Abstract
The rare achlorophyllous orchid Cyrtosia septentrionalis (Rchb.f.) Garay is thought to switch mycobiont from a Physisporinus species (‘TK-10’) to an Armillaria species as it develops. We conducted morphological, chemical, and molecular analyses of the root system of three adult plants growing sympatrically in Japan to assess reliance on different mycorrhizae. The root systems were found to comprise several long primary roots that radiate outwards from the emergent stem and many shorter lateral ones. Long roots branched most vigorously where they encountered Armillaria gallica in the soil, and the resulting lateral roots contained the highest density of intra-radical rhizomorphs. One plant was associated with ‘TK-10’ and the other two with A. gallica, but only the apical portion of long roots and a few lateral roots were colonized. Mycobionts isolated from the base of long roots proved incapable of germinating C. septentrionalis seeds. Whereas glucose was the dominant monosaccharide in non-mycorrhizal roots, galactose was in mycorrhizal ones. Lateral roots are specialized in mycorrhization and their velamen, and mucilage may play a key role in preventing desiccation. We hypothesize that C. septentrionalis can associate with either fungus from germination to adulthood, but that detection of A. gallica in the soil can prompt replacement of ‘TK-10’.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".