Molecular evaluation of <i>Plasmodiophora brassicae</i> collections for the presence of divergent genetic pathogen populations before and after the release of clubroot resistant canola
Bibliographic record
Abstract
Plasmodiophora brassicae Woronin, the cause of clubroot of crucifers, is now established across most of Alberta, Canada, and has become a major constraint in canola (Brassica napus L.) production. Disease control is achieved mainly by planting clubroot-resistant (CR) canola varieties. The first CR canola in Canada was released in 2009. In 2013, severe clubroot was detected on CR canola in several fields in Westlock County, Alberta, and found to be caused by a ‘new’ strain of P. brassicae termed ‘5X’. These strains have been shown to be genetically distinct from other P. brassicae strains in Alberta (‘population one’) and belong to a second population (‘population two’) of the pathogen. In this study, multiple molecular markers, specific for ‘population two’, were used to determine the occurrence of members of this population over time throughout central Alberta. Two hundred and twenty-four clubroot galls collected from 2005 to 2016 from non-CR canola varieties were examined. The presence of ‘population two’ DNA was detected at low levels in at least 47 of the galls, and it was the predominant population of P. brassicae in another 10 of the samples. These samples were found in Flagstaff County starting in 2008, Westlock County starting in 2009, the County of Vermillion River in 2011 and Red Deer County in 2014. Although relatively uncommon, members of this population were widespread, occurring at locations 168 km apart prior to the release of CR canola.
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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 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".