Morphological variation in <i>Bromus</i> sect. <i>Ceratochloa</i> germplasm of Patagonia
Bibliographic record
Abstract
South American representatives of Bromus sect. Ceratochloa make up a morphologically diverse group of grasses indigenous to the southern Andes of Argentina and Chile. The objectives of the present study were to describe patterns of morphological variation among 30 accessions representing six species (Bromus catharticus Vahl, Bromus coloratus Steud., Bromus lithobius Trin., Bromus mango E. Desv., Bromus stamineus E. Desv., and Bromus tunicatus Phil.) in a common garden, correlate morphological and previously obtained molecular data, and develop a taxonomic treatment within sect. Ceratochloa of South America. Plant materials included 28 hexaploid (2n = 6x = 42) and 2 octoploid (2n = 8x = 56) accessions. Based on multivariate analyses of 24 characters, the two octoploid accessions formed an isolated, well-defined group, while the hexaploids formed two less-defined groups. Characterized by lemma awns longer than 3 mm, one group consisted of those accessions of B. coloratus, B. lithobius, and B. stamineus, whereas the other group consisted of B. catharticus, B. mango, and B. tunicatus. A significant Mantel test statistic (r = 0.70, P = 0.001) suggested a high correlation between morphological variation and DNA polymorphism. Taken together, our results indicated that the hexaploid complex should be described as a single variable species (B. cathar ticus), with two nearly continuous groups: B. catharticus subsp. catharticus (Vahl) Herter and B. catharticus subsp. stamineus (E. Desv.) Massa. Based on nomenclature priority and type specimen designations, the octoploid accessions should be described as Bromus coloratus.Key words: Bromus, morphology, multivariate analysis, Patagonia, taxonomy.
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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 | 0.001 |
| 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".