Variation in germination response among local populations of Scotch thistle, Onopordum acanthium L.
Bibliographic record
Abstract
Cypselas of Scotch thistle, Onopordum acanthium L., collected from four populations in or near London, Ontario in September 1996, were incubated under seven diurnal light and temperature regimes (35/20, 25/10 and 10/5°C, both under alternating light and darkness and continuous dark conditions, plus a 20°C dark treatment). Although all populations originated on gravel soil of similar pH near the Thames River, there were large differences among populations in both germination rates and final percentages in several treatments. At 25/10°C, cypselas from all populations had 3.5 to 13 times as much germination in alternating light and dark as in continuous darkness. At 35/20°C three of the populations had higher germination percentages in continuous darkness than under alternating light and dark. Under both 10/5°C treatments, as well as at 20°C in darkness, less than 8% germination was recorded for any population. Under alternating light and dark, cypselas of all populations germinated fastest in the 25/10°C treatment. Variation in germination response among local populations gives a species a greater range of responses and a better chance of surviving changeable environmental conditions.
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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 | 0.001 | 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) | 0.001 | 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".