Trimorphic Incompatibility in<i>Pontederia subovata</i>(Pontederiaceae): An Aquatic Macrophyte from Lowland South America
Bibliographic record
Abstract
Premise of research. Tristyly is a floral polymorphism that is reliably reported from six flowering plant families. Populations of tristylous species often contain three floral morphs that differ reciprocally in stigma and anther height. Trimorphic incompatibility and a suite of ancillary pollen and stigma polymorphisms are commonly associated with sex organ trimorphism. Here, we investigate the tristylous syndrome of Pontederia subovata (Pontederiaceae), a little-known aquatic from southwest Brazil.Methodology. We conducted measurements of sex organ position, pollen size, pollen production, and stigmatic papillae length on the three floral morphs under glasshouse conditions and carried out a controlled pollination program to investigate whether P. subovata possesses a trimorphic incompatibility system and whether its expression varies among the floral morphs.Pivotal results. Pontederia subovata displays reciprocal stigma and anther heights and trimorphism in the size of pollen grains and the length of stigmatic papillae. Controlled pollinations provided evidence of trimorphic incompatibility: self- and intramorph crosses yielded significantly less seed than do intermorph crosses when pollen from anthers and stigmas of equivalent height were employed. However, trimorphic incompatibility was weakly expressed in the mid-styled morph when pollinations involved long-level anthers. The occurrence of stem-borne tubers is reported for the first time from Pontederiaceae.Conclusions. Our results confirm the presence of tristyly in P. subovata. The species has several features in common with other tristylous members of Pontederia, including striking variation in the strength of incompatibility among the floral morphs. We suggest that weak incompatibility in the mid-styled morph may provide reproductive assurance during colonization. Tuber formation in P. subovata probably evolved as an adaptation enabling persistence of genets during the marked dry season that characterizes the aquatic habitats in which the species occurs.
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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 | 0.001 | 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".