Molecular evidence that <i>Verticillium ablo‐atrum</i> Grp 2 isolates are distinct from <i>V. albo‐atrum</i> Grp 1 and <i>V. tricorpus</i>
Bibliographic record
Abstract
summary Verticillium species-specific primers were used in a polymerase chain reaction to differentiate between Verticillium albo-atrum groups and V. tricorpus. Amplification with species-specific primers identified 21 isolates from the 64 V. albo-atrum isolates tested as Grp2. Genome analysis using RAPDs and restriction fragment length polymorphism (RFLP) of the intergenic (IGS) region of the rDNA showed that V. albo-atrum Grp2 isolate were genetically distinct from either V. albo-atrum Grp1 or V. tricorpus, demonstrating a significant differentiation between these species. The sizes of the amplified IGS fragment were different, with Grp1 isolates having a smaller fragment ( approximately 2.1 kb) than either Grp2 ( approximately 2.3 kb) or V. tricorpus ( approximately 2.7 kb). Based on RAPD analysis, the average similarity coefficients between Grp1 and Grp2 were 35% and 34% between Grp2 and V. tricorpus. Multiple correspondence analysis separated the isolates into three major groups corresponding to Grp1, Grp2 and V. tricorpus. Surprisingly, isolates collected from Pisum sativa were distinct from other Grp1 V. albo-atrum isolates. The observed low levels of genetic similarity, the differences in sizes of IGS fragments, IGS-RFLP profiles and the RAPD patterns point to the possibility of Grp2 isolates comprising a different species of Verticillium than those occupied by either V. albo-atrum Grp1 isolates or V. tricorpus.
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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 | 0.000 | 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".