Biological nitrogen fixation potential of pea lines derived from crosses with nodulation mutants
Bibliographic record
Abstract
The process of biological nitrogen fixation (BNF) through nodules of legumes benefits soil fertility, increases crop productivity and reduces the requirement for chemical fertilizers. Pea is an important pulse crop in temperate regions of the world. The N fixation capacity of pea in Canadian environments ranges from 50% to 55% of crop N requirement. Nodulation mutants in pea have been developed but not evaluated in a breeding program. To determine the potential of 20 pea lines derived from crosses between two nodulation mutants (Rondo nod3 and Frisson P88 Sym29) and Saskatchewan adapted pea cultivars CDC Meadow and CDC Dakota, for BNF and agronomic performance. Pea lines were evaluated in replicated multi-location field trials. In four of the trials, a 15N isotope treatment was applied two weeks after planting to estimate the percentage of N derived from air (%Ndfa) using the 15N isotope dilution protocol. Additionally, standard agronomic assessments for pea were collected from each plot, as well as grain yield and seed protein concentration. Biological N fixation capacity of the pea lines ranged from 50% to 80%. Several of the pea lines performed significantly better than the check cultivars CDC Meadow and CDC Dakota for yield, percentage protein and BNF capacity. Pea lines, especially those arising from crosses with CDC Dakota, had on average 10% more seed yield, 2–3% more seed protein, and fixed 5% more N than CDC Meadow and CDC Dakota. The %Ndfa showed moderately high and significantly positive correlation with days to flowering (r = 0.47, p < 0.01), days to maturity (r = 0.56, p < 0.01) and seed protein concentration (r = 0.51, p < 0.01). The ability of tested pea lines to produce high grain yield along with higher N fixation potential and seed protein concentration makes them attractive for use in pea breeding programs. This research opens the potential for breeding pea for improved N fixation which will have positive implications for reducing greenhouse gas emissions in a cereal-oilseed-pulse crop rotation.
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 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 | 0.001 |
| 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".