Genomics-assisted assessment of quantitative disease resistance: an evaluation of genetic resistance of two-row barley (Hordeum vulgare L.) to fusarium head blight (Fusarium graminearum) and deoxynivalenol accumulation
Bibliographic record
Abstract
Fusarium head blight (FHB) incited by Fusarium graminearum, is currently the most devastating disease of barley (Hordeum vulgare L.) in western Canada. Type B trichothecene mycotoxins e.g. deoxynivalenol (DON) associated with FHB are closely monitored by both malting and livestock feed industries. Breeding disease-resistant varieties is a sustainable disease management practice, however, this is complicated by quantitative-based resistance. To date, breeding efforts have largely relied on labour-intensive screening nurseries. Two studies focus on the evaluation of a single nucleotide polymorphic (SNP) marker array (Barley 50K SNP) in i) genome-wide association study (GWAS); ii) genomic estimated breeding values (GEBV) whole-genome marker prediction. While GWAS identified numerous genomic associations with FHB and DON, they generally were small effects explaining a low proportion of the phenotypic variance. Genomic estimated breeding values (GEBVs) were calculated by classical statistical and machine learning approaches, where both were able to demonstrate moderate prediction is possible for FHB and DON content. Genomic selection is thus recommended as an efficient breeding approach vs. considerations of individual SNP markers. The F. graminearum population of western Canada has shifted towards 3-acetyl-deoxynivalenol (3ADON)-producers, which tend to accumulate higher levels of DON. In vitro selection (IVS) has been successfully used to identify resistant somaclonal variants. Another study involves poly-A RNA-sequencing contrast of IVS derived variety Norman vs. its parent, CDC Kendall. Different transcriptional alternations were detected in response to infection by 3ADON, 15ADON, and nivalenol (NIV) – producing strains of F. graminearum. In the final experiment, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to evaluate mycotoxin composition in rachis and grains for a group of field-inoculated varieties with differential resistance levels. The conjugate form deoxynivalenol-3-glucoside (DON3G) was found to occur at a significant level (26%) of total toxins. While varieties differed in DON content, the ratio of DON3G/DON appeared stable across genotypes. In summary, the dissertation contributed to novel research through the identification of feasible genomics-based breeding strategies for developing FHB resistance and lowering DON, contributed to an understanding of IVS resistance of Norman, identified gene targets of differentially expressed genes between the varieties, and has identified toxin-conjugation as a resistance factor.
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) | 0.001 | 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".