Apomixis and sexuality in the Potentilla argentea complex III. Euploid and aneuploid derivatives (including trisomics) of some apomictic biotypes
Bibliographic record
Abstract
Three apomictic biotypes belonging to the Potentilla argentea complex formed the basis of this investigation, one of them diploid, one tetraploid and one hexaploid. The effects of chromosome doubling and other changes in chromosome number were studied. Hybrids between the same biotypes were discussed in a previous paper. The diploid was a facultative apomict, but autotetraploids produced by colchicine treatment were totally sexual. This was also true of autotriploids, probably also of trisomics and other aneuploids. Five out of seven possible primary trisomics were obtained; they were morphologically well separated from each other and from the diploid. As shown by the result of test-crosses, facultative apomixis was restored in “recombined diploids” in progenies from triploids and trisomics. This indicates that apomixis is partly dependent on homozygosity for recessive genes, but that also the degree of ploidy as well as chromosomal and genic balance directly influence the mode of reproduction. — In the more strictly apomictic tetraploid (2n= 28) biotype, unreduced egg cells were fertilized in exceptional cases, whereas the chromosome-doubled plants formed some aberrants by fertilization of reduced egg cells. However, an “autotriploid” (2n= 42) formed half of its offspring by fertilization of unreduced and reduced egg cells. Aberrants with 2n= 35 and 2n= 63 were obligate apomicts. — The hexaploid was obligately apomictic, whereas the poorly fertile plants resulting from chromosome doubling gave rise to one plant with further increased chromosome number; thus, even here apomixis was interfered with to some extent. — The concluding discussion also deals with problems of mitotic and meiotic instability, crossing barriers in pseudogamous taxa, and viewpoints on the mechanisms and regulation of apomixis.
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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 | 0.000 | 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".