Population genetic structure and phylogeographic patterns in the Chinese endemic species<i>Sagittaria lichuanensis</i>, inferred from cpDNA<i>atp</i>B–<i>rbc</i>L intergenic spacers
Bibliographic record
Abstract
Both historical (e.g., glaciations) and spatial (geological features) factors are considered to have had significant influences on the distribution and genetic structure of many plants. To understand the effects of such factors on the current genetic and geographical distributions of plant species in the Nanling and central regions in China, we examined genetic variation and phylogeographical patterns of Sagittaria lichuanensis J.K. Chen (Alismataceae), an endangered and endemic species in China, using chloroplast DNA atpB–rbcL intergenic spacer sequence variation. In this study, a total of 9 haplotypes from 47 individuals in 6 populations of S. lichuanensis were detected. The NST(0.193) was significantly higher than GST(0.082) (P < 0.05), indicating a significant phylogeographical structure. In the minimum spanning network (MSN) of the haplotypes, the distribution of haplotypes showed an east–west split. The results of the Mantel test analysis showed that there was no correlation between the genetic distance and geographical distance (r = 0.539, P > 0.05). The formation of barriers to dispersal might have played an important role in shaping the population genetic structure of S. lichuanensis. Within each region (east and west regions), high levels of gene flow between populations and low levels of population differentiation were found. Several conditions, such as co-ancestry due to recent common ancestry or short period of isolation, might have occurred among the populations studied. In the MSN, all tip haplotypes except for two (A and G) occurred in two or more populations, and the haplotype D in the interior node was widespread. The haplotype D is likely to be an ancestral haplotype and represents the relic, widely distributed haplotype before the populations were fragmented and isolated by mountain uplift.
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 | 0.001 |
| 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".