Virulence of isolates of <i>Ustilago tritici</i> collected in Manitoba and Saskatchewan, Canada, from 1999 to 2007
Bibliographic record
Abstract
Breeding for resistance to the loose smut pathogen, Ustilago tritici, in wheat is a traditional disease management approach in western Canada. The development of resistant wheat lines relies on accurate methods for identification of effective host resistance. Knowledge of the virulence frequencies of races in the pathogen population is essential to identify effective host resistance. The objective of this work was to characterize the virulence phenotypes of U. tritici isolates collected from 1999 to 2007 in Manitoba and Saskatchewan. Sixty-four isolates of U. tritici from durum wheat and 59 from hexaploid wheat were assessed for virulence. Teliospore suspensions of each isolate were injected into florets of the wheat differential host series by needle inoculation at mid-anthesis. Mature seed from inoculated florets were grown to determine the per cent infected plants. Eighty-five per cent of durum wheat isolates were race T32, possessing virulence to differential lines ‘Mindum’ (TD-1), and ‘Wakooma’ (TD-19). Virulence to ‘Pentad’ (TD-11) was found in only 5% of the durum wheat isolates. Races T7, T5, T64 and T10 were the most commonly identified races from the hexaploid wheat isolates of U. tritici. Six previously unreported races were identified: races T61, T64, T65, T66, T67 and T68. None of the isolates possessed virulence to ‘Sonop’ (TD-14), while >50% of the isolates possessed virulence to ‘Kota’ (TD-4), ‘Little Club’/‘Reward’ (TD-5A), ‘Reward’ (TD-7) and ‘Thatcher’/‘Regent’/‘Reward’ (TD-12A). Virulence to TD-6, which was previously uncommon from Manitoba and Saskatchewan, was possessed by 20% of the hexaploid wheat isolates. The natural population of U. tritici in Manitoba and Saskatchewan continues to evolve in terms of virulence, but effective sources of resistance are still currently available.
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 | 0.001 | 0.002 |
| 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".