A Canadian strain of Pseudomonas syringae causes white-colour disease of Cirsium arvense (Canada thistle).
Bibliographic record
Abstract
Patches of white-coloured Cirsium arvense (Canada thistle) plants were recently found on roadsides, pastures and market gardens in Devon, Mulhurst, Stony Plain and Edmonton, Alberta, Canada. The diseased plants showed apical chlorosis, sometimes with dark and necrotic leaf spots. These symptoms were also associated with stunted growth, fewer shoots, inhibition of flowering and/or sterility. A total of 101 bacterial strains were isolated from the leaves, stems and flowers of white-coloured C. arvense plants. A bacterial species (one strain designated CT99B016C) was consistently isolated from diseased plants and was found to produce similar symptoms on C. arvense under both greenhouse and field conditions. The organism was reisolated from inoculated, diseased plants, thereby fulfilling Koch’s postulates. The optimal bacterial cell concentration to achieve maximum disease was within the range of 108–109 colony forming units (cfu)/mL, while the optimal surfactant concentration was 0.15–0.3% Silwet L-77®. The CT99B016C strain also caused severe disease of Sonchus oleraceus and S. asper (annual and spiny sowthistle) and Taraxacum officinale (dandelion). The disease severity on these weed species was even greater than that on C. arvense. Results of phenotypic tests and fatty-acid analysis clearly placed the CT99B016C strain within the Pseudomonas syringae group. Fatty-acid analysis also indicated that isolate CT99B016C is more closely related to P. syringae pv. tabaci and P. syringae pv. syringae than P. syringae pv. tagetis. Results from polymerase chain reactions (PCRs) with primer sets TAGTOX-9 and TAGTOX-10 also indicated that CT99B016C is different from P. syringae pv. tagetis. The exact pathovar identification of CT99B016C remains to be determined.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 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".