Biological and genetic characterisation of <i>Phoma macrostoma</i> isolates with bioherbicidal activity
Bibliographic record
Abstract
The fungus Phoma macrostoma Mont. isolate 94-44B was registered as a bioherbicide for control of broadleaved weeds in Canada and the USA in 2011 and 2012, respectively. To obtain the registrations, the fungus had to be characterised both biologically and genetically. The objectives of this study were to demonstrate that bioherbicidal activity was associated with specific genetic markers and to determine whether bioherbicidal activity was a general trait of the species or only selected isolates. A collection of 64 isolates of P. macrostoma was established. A greenhouse bioassay and bioherbicidal-specific primers were used to determine bioherbicidal activity of all isolates. Only isolates originating from Canada thistle demonstrated the ability to reduce dandelion seedlings and display the 853 bp amplicon for the bioherbicidal-specific primer. Bioherbicidal isolates were consistently differentiated from all other isolates with two main genotypic groupings (I and II) arising from internal transcribed spacer (ITS) and amplified fragment length polymorphisms (AFLP) sequence analyses. Using AFLP, two biotypes of bioherbicidal isolates were also differentiated by the presence or absence of an AFLP marker at a single polymorphic locus. The genetic divergence among the bioherbicidal and nonbioherbicidal isolates of P. macrostoma was only 2.21% which was lower than that reported for other related Phoma sp. Other than the bioherbicidal trait, there was no apparent affiliation of the genetics with known varietal types, host or geographic origin. ITS sequence analysis and AFLP fingerprinting may be used as tools to detect bioherbicidal isolates of P. macrostoma.
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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) | 0.000 | 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".