ENDOSPERM FORMATION AFTER 2x, 4x CROSSES IN CERTAIN CEREALS, ESPECIALLY IN HORDEUM VULGARE
Bibliographic record
Abstract
N the late twenties and early thirties the cause of the abortion of I seeds formed after species crosses was much discussed.Related species or forms having a different number of genomes give, when crossed, very bad seeds.WATKINS, THOMPSON, THOMPSON and CAMERON, and WAEAEUWA published papers on seed development after reciprocal crosses between tetraploid and hexaploid species of Triticum; later, BOYES and THOMPSON included diploid Triticum species in the crosses.Hybridizations between diploid, tetraploid and hexaploid species of Avena were studie\d by KIHARA and NISHIYAMA who found that, as in Triticum, endosperm development had a different aspect in reciprocal crosses.As a rule, seed development is better when the mother plant has the higher chromosome number; on the other hand, a larger difference in the number of genomes between the crossed plants causes more pronounced disturbances.The happy idea was conceived by MUNTZING (1930) that the causes of seed degeneration in the crosses referred to were of a quantitative rather than a qualitative nature.He pointed to the fact that crosses between a diploid and its autotetraploid also result in bad seeds.In normal seeds the relation between the chromosome numbers of the maternal tissue of the ovule, the endosperm and the embryo is 2: 3: 2, but after crosses between plants with different numbers of genomes this ratio in the seeds is altered with physiological and morphological disturbances as a consequence.In a second paper MUNTZING (1933) more closely discussed this theory and refuted certain other interpretations of the causes of the seed abortion.He pointed out the farreaching consequence of this kind of sterility facilitating the forming of polyploid species in angiosperms.Later, seed development in reciprocal crosses between a diploid and its autotetraploid has been investigated, e. g., in the cereals Secale cereale ( HAPANSSON and ELLERSTR~M, 1950; L~WENSTEIN, 195 I) and
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".