Genetic diversity of<i>Frankia</i>strains in root nodules from<i>Hippophae¨ rhamnoides</i>L.
Bibliographic record
Abstract
The Hippophae¨ rhamnoides L. – Frankia symbiosis is of ecological and practical importance, but very little is known about H. rhamnoides-infective Frankia strains. To address this problem, we have used PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of nifD–nifK intergenic spacer (IGS) to estimate their genetic diversity at 19 sites in Northern China. Restriction analysis indicated that H. rhamnoides-infective Frankia had a high genetic diversity; the samples were divided into nine RFLP patterns (A–I). Elevation and precipitation likely affect the distribution of different Frankia patterns in root nodules. The patterns A and D were present in relatively large areas, which were located at various elevations; however, the distribution of patterns B, C, E, F, G, H, and I generally followed a geographic range. The richness of Frankia diversity was influenced by plant cover and geographic factors such as elevation and precipitation. H. rhamnoides cover had a higher diversity than that of natural vegetation cover. The center part of the geographical range, with intermediate elevation and precipitation, had a higher level of Frankia diversity than that of the west part and east part with high or low elevations and precipitations, respectively. The nifD–nifK IGS regions were sequenced from 28 nodule samples. Phylogenetic analysis showed that H. rhamnoides-infective Frankia strains were all clustered with the Elaeagnus group, and the diversity of this group was quite extensive. Phylogenetic relationships between Hippophae¨ and Elaeagnus-infective Frankia strains were relatively close to each other. Although not very close to either Hippophae¨- or Elaeagnus-infective Frankia strains, Shepherdia -infective strain SCN10a was closer to Hippophae¨-infective strains than to Elaeagnus- infective strains. This is the first detailed report on the genetic diversity and phylogenetic analysis of H. rhamnoides-infective Frankia.
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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".