Microsatellite analysis of genetic diversity in four populations of<i>Populus tremuloides</i>in Quebec
Bibliographic record
Abstract
To determine overall genetic variability in aspen (Populus tremuloides Michx.) along the clay belt of northwestern Quebec, four populations were sampled at the transition zone between mixed-wood and conifer-dominated forests using a hierarchical strategy. Our objectives were (i) to estimate gene diversity among and within populations using microsatellite markers and (ii) to examine whether clonal structuring in aspen could be detected. For each population, three stands at least 1 km apart were sampled. Within each stand, five putative clones were sampled with a distance of 50 m between each clone. To examine potential genetic diversity within clones, for three of the putative clones sampled per stand, the three trees closest to this individual (potential ramets) were also sampled. All samples were analysed at four microsatellite loci. Measures of genetic variation all indicated that most of the variation occurred within rather than among the populations. Rst, based on a stepwise mutation model, was 0.0409, slightly higher than Fst, which was based on infinite allele model (0.0323). Within each stand, DNA fingerprint of five putative clones allowed the differentiation of genetically distinct individuals within these putative clones, and from 1.62 to 2.2 times more genetically distinct individuals were identified than by morphological identification. In the present study there was no correlation between the mean distance of the potential ramet to the central trunk (potential ramets were often within 23 m of the central trunk) and the possibility of the central trunk and ramet sharing the same genotype. The number of unique genotypes for the three putative clones sampled per stand varied from 11 genotypes per 15 samples to 14 per 15 samples. Consequently, it was not possible to identify clones by either distance from a given central trunk or morphological characteristics. Thus, after stand disturbance, suckers from different genotypes are likely to be closely mixed.Key words: genetic diversity, Populus tremuloides, microsatellites, clone size.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".