Photoperiod and temperature effects on the rate of leaf appearance in quinoa ( <i>Chenopodium quinoa</i> )
Bibliographic record
Abstract
Knowledge of factors controlling leaf appearance is important for understanding climatic adaptation of a plant species. For quinoa ( Chenopodium quinoa Willd.) we show that both temperature and photoperiod control the rate of leaf appearance. Minimum phyllochron (thermal time between the appearance of two successive leaves as observed under short days) and photoperiod sensitivity of the phyllochron decreased as latitude of origin of a cultivar increased from 1˚13¢ N to 38˚46¢ S. Minimum phyllochron ranged from 21.8 ˚Cd in the Colombian cv. Nariño, to 15.9 ˚Cd in the Chilean cv. Baer (estimated for a common base temperature of 2˚C). Photoperiod sensitivity ranged from 1.2 ˚Cd h –1 in Nariño to insensitivity (0 ˚Cd h –1 ) in the Bolivian and Peruvian altiplano cvv. Kanckolla, Blanca de Juli and Sajama. The phyllochron sensitivities to photoperiod and temperature were linearly and positively associated with photoperiod and temperature sensitivities of time to visible flower buds (R 2 = 0.70 and 0.55, respectively, P < 0.05), so that shorter phyllochrons were associated with early flowering cultivars. Temperature sensitivity was highest in cvv. originating in cold or dry climates, and lowest for cvv. from more humid and warm climates. We suggest, therefore, that in its domestication as a crop plant, photoperiod sensitivity of quinoa has been selected for as a homeostatic mechanism to counteract the potentially reduced leaf area associated with early flowering under short days and high temperatures in the tropics.
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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".