Defoliation patterns and genetics of insect resistance in cottonwoods
Bibliographic record
Abstract
In 1995, an outbreak of a leaf beetle, Phratora californica Brown (Coleoptera: Chrysomelidae), began in a three-generation Populus trichocarpa Torr. & Gray × Populus deltoides Bartr. pedigree planting near the lower Columbia River in Oregon. This outbreak provided us with an opportunity to assess leaf beetle feeding patterns and the genetics of cottonwood resistance to defoliation. We developed a method for estimating damage levels by training personnel to visually estimate percent damage in leaf samples. Digital image analysis was used to measure damage to the leaves used in the training. Based on a sample of 300 trees from 100 genotypes, herbivory was found to be greatest in the upper canopy and in the fall. Broad-sense heritability was estimated to be 0.88 and 0.80 for July and October, respectively, demonstrating that resistance to P. californica is under relatively strong genetic control. Resistance in the F2 likely came from the P. trichocarpa parent, because this parent was less susceptible, on average, than the P. deltoides parent. However, the difference between parents was not great, and any further genetic analysis of resistance to Phratora californica should employ crosses between individuals with more strongly contrasting phenotypes.
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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".