CYTOLOGICAL STUDIES OF EXTRA FRAGMENT CHROMOSOMES IN RYE II. TRANSMISSION AND MULTIPLICATION OF STANDARD FRAGMENTS AND ISO-FRAGMENTS
Bibliographic record
Abstract
I N the offspring of a single rye plant with two additional small chromosomes observed in the variety »Ostgota Grarag» (MtiNTZING and PRAKKEN, 1941) the effects of a varying number of such extra »fragment chromosomes» were studied (MUNTZING, 1943).Fertility was found to be more influenced than the vegetative development, but also with regard to vigour a definite influence was demonstrated.Thus, the fragment chromosomes are not inert as was supposed by some previous workers.However, considering the size of .thefragments and the strong effects of extra chromosomes in trisomic plants, it is probable that the fragments are subinert, having a lower proportion of active genes than ordinary chromosomes.As a rule extra fragment chromosomes of the usual type (the »standard fragments-) are stable, but in rare cases their centromere may misdivide (MtlNTZING, 1944).The two products of misdivision, corresponding to the short and long arms of the standard fragments, were recovered in the shape of iso-fragments with median centromeres (1.c.).Thus, in addition to plants with standard fragments (»s.f.» ) plants with large and small iso-fragments (» iso-f'.»)are now available in the material of »Ostgota Grarag».The present report primarily deals with the transmission of the extra fragment chromosomes in various cross combinations.These studies were undertaken firstly in order to compare the behaviour of the iso-fragments and the standard fragments, secondly to elucidate the peculiar fragment frequencies in the offspring observed by LEWIT-SKY, MELNIKOV and Trrovx (1932) and by the present writer (1943, pp.93-94).In crosses between parents with 2n = 14 and 2n = 14 + 2 fragments most of the hybrids have either 2n = 14 or 14 + 2 fragments and not 14 + 1 fragment as might be expected.The probable cytological cause of this peculiar result was observed by HASEGAWA Heredlta.XXXI.
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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 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".