Microsporogenesis, Pollination, Pollen Germination and Male Gametophyte Development in Taxus brevifolia
Bibliographic record
Abstract
Taxus brevifolia (Nutt.), commonly known as Pacific or western yew, is a conifer native to the Pacific northwest of North America. Contrary to other Taxus species, T. brevifolia staminate strobili are usually located on 2-year-old foliage although they may occur on foliage from 1 to 5-years-old. This delayed staminate strobilus development may be an adaptation to the low light environment where T. brevifolia grows. Microsporogenesis occurred in the autumn preceding pollination. Successive divisions produced isobilateral tetrads visible as early as mid-October. Over-wintering staminate strobili usually contained separate microspores. In 1996 to 1999, pollination occurred in March and April in two natural forest sites on southern Vancouver Island, British Columbia, Canada. The low amounts of airborne pollen and prolonged pollination period indicated low pollination success within T. brevifolia . Female receptivity was measured by the presence of a pollination drop. Protandry up to 18 d was observed. In vitro pollen germination was moderate to good, ranging from 65 to 88% depending on the tree and year. DAPI fluorescence staining showed successful male gametophyte development in vitro . The microspore divided forming a tube nucleus and generative cell within 3 d of culture. The generative cell then divided forming a sterile nucleus and spermatogenous nucleus after 17 d. The spermatogenous nucleus acquired a cell wall then divided forming two equal sperm after 24 d. Copyright 2000 Annals of Botany Company
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 teacher head, 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".