Mating type distribution and incidence of the teleomorph of <i>Ascochyta rabiei</i> ( <i>Didymella rabiei</i> ) in Canada
Bibliographic record
Abstract
Chickpea (Cicer arietinum L.) acreage has increased rapidly in western Canada since 1995, and Ascochyta rabiei (Pass.) Labr. is the most important pathogen of this new crop. Wind-borne ascospores produced by the teleomorph play an important role in disease spread and pathogen survival in many regions. The teleomorph stage, however, has not been reported in Canada. Mating-type assessments of 42 isolates from 34 fields in Saskatchewan were conducted using tester isolates. The two mating types occurred at similar frequencies across the region. Over-wintered chickpea residue was collected in April of 1999 and 2000. The teleomorph was detected on the residue by microscopic dissection and by two methods of ascospore discharge, one using a novel and inexpensive apparatus. Mature ascospores were found at six of seven sites in 1999. No ascospores were found in material from 13 sites in 2000. However, asci were found later in the season in a separate study conducted at one site. The occurrence of the teleomorph stage in the region may increase field-to-field spread of ascochyta blight of chickpea and contribute to increased genetic variability of the pathogen in western Canada. Depuis 1995, la superficie cultivée en pois chiche (Cicer arietinum L.) s'est accrue rapidement dans l'ouest du Canada et l'Ascochyta rabiei (Pass.) Labr. est le plus important agent pathogène de cette nouvelle culture. Les ascospores aéroportées et produites par le téléomorphe jouent un rôle important dans la propagation de la maladie et la survie de l'agent pathogène dans plusieurs régions. Par contre, le stade téléomorphe n'a pas été signalé au Canada. La détermination du type sexuel de 42 isolats provenant de 34 champs de la Saskatchewan a été réalisée à l'aide d'isolats testeurs. Les deux types sexuels étaient présents à des fréquences similaires dans l'ensemble de la région. Des débris de pois chiche ayant traversé un hiver ont été recueillis en avril de 1999 et de 2000. Le téléomorphe a été détecté dans les résidus par dissection sous microscope et par deux méthodes d'éjection des ascospores, l'une d'entre elles utilisant un nouvel appareil peu coÛteux. En 1999, des ascospores matures ont été trouvées sur six de sept sites. Aucune ascospore n'a été trouvée en 2000 dans les débris provenant de 13 sites. Cependant, des asques ont été trouvés plus tard en saison dans une étude distincte menée à un des sites. La présence du stade téléomorphe dans la région peut favoriser la propagation de la brÛlure ascochytique du pois chiche et contribuer à la croissance de la variabilité génétique de l'agent pathogène dans l'ouest du Canada.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".