Potential use of barcoding to identify aquatic hyphomycetes
Bibliographic record
Abstract
Tetracladium is a common aquatic hyphomycete genus, whose taxonomy has been based on the morphology and development of asexual spores. Ecological surveys have relied almost exclusively on spore morphology. Since selective pressures have resulted in convergent shapes, misidentifications are a concern. To supplement morphological information, we determined COX1, ITS and D1/D2 sequences as potential barcodes on 21 strains belonging to 7 described Tetracladium species and an unidentified strain. Attempts to amplify the IGS region were unsuccessful. The ratio of intraspecific to interspecific variability was optimal with ITS, which also provided the intuitively most acceptable cladogram. Typical conidia and their variability for the seven described species are illustrated. Internal node reliability depended less on total sequence length and more on the mixture of conserved and variable regions used to build cladograms. This finding can be exploited for quickly increasing phylogenetic accuracy without greatly increasing the amount of amplification and sequencing. The results have important implications for identifying freshwater hyphomycetes in the field but further work is required to establish if this method works with plant pathogens.
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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 | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".