Maturation temperature regulates germinability and chemical constituents of Scotch thistle (<i>Onopordum acanthium</i>) cypselas
Bibliographic record
Abstract
The effects of maturation temperature on germinability and chemical constituents of Scotch thistle ( Onopordum acanthium L.) cypselas (fruits) were determined as part of our ongoing investigation into the causes of intermittent germination in this species. Mature cypselas were collected from plants that were grown under higher (28 or 30 °C) and lower (20 or 22 °C) temperature regimes in greenhouses in 2000 and 2001. Two collections were made, from early- and late-ripening capitula. Germinability and the amounts of moisture, wax, phenolic compounds, and lignin were determined for cypselas from all collections. Cypselas that matured in the first year had lower amounts of moisture and wax than second-year cypselas, but did not differ in amounts of other components. Cypselas that matured under the higher temperatures generally had lower amounts of moisture, wax, and phenolic compounds, faster germination, and higher germination percentages. Early-matured cypselas had higher amounts of moisture and wax, faster germination, and higher germination percentages, but lower amounts of phenolic compounds. However, maturation temperature and collection date did not affect lignin content. Consistent and significant differences in germination patterns and chemical constituents between cypselas that matured under contrasting temperatures confirmed that maturation temperature altered the germinability of O. acanthium cypselas. Thus, under field conditions, cypselas that mature under low temperatures can have stronger dormancy and exhibit greater intermittency in germination/emergence patterns than those that mature under high temperatures.
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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) | 0.001 | 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".