First Record of <i>Hop stunt viroid</i> in Canada
Bibliographic record
Abstract
"Tissue-printing" hybridization (3) for Peach latent mosaic viroid (PLMVd) and Hop stunt viroid (HSVd) was used to assess the sanitary status of stone fruit accessions in the Canadian Clonal Genebank (CCG) located in Harrow (Ontario). The Prunus spp. accessions in the CCG are primarily of Canadian origin; other countries of origin include the United States, the United Kingdom, Hungary, the Czech Republic, the Former Soviet Union, Spain, New Zealand, and Italy. All Prunus spp. accessions were donated to the Genebank from Canadian or American sources. Leaves were harvested in November 2003 from 336 trees (116 peach and nectarine, 84 sweet and sour cherries, 54 plum, 44 apricot, and 38 of other cherries) representing 267 accessions. No visible symptoms were observed during the collection of the accessions to be evaluated. The petioles were excised at the base and imprinted on a nylon membrane in triplicate for each sample. The membranes were air dried and submitted by mail to the laboratory. The digoxigenin-labeled riboprobes used for hybridization were obtained by T7 RNA polymerase transcription of the linearized plasmids pHSVd (1) and pPLMVd (2). Thirty stone fruit samples were infected by viroids. PLMVd occurred in 28 peach and nectarine samples, representing the following cultivars and selections: Harblaze Hardired, Harko, Earlyvee, Harbelle, Harken, Harland, Harrow Beauty, Harrow Rubirose, HW264, Redhaven, Silver Gold, Suncling, V68101, Vanity, Veeglo, Velvet, Vesper, Villa Doria, and Vulcan. PLMVd-infected samples represented 24.1% of the tested peaches and nectarines. PLMVd finding confirms previous reports of the viroid in Canada from British Columbia and Ontario. Two CCG apricot accessions, 'Bulida' and 'Velkopavlovicka', were found to be infected with only HSVd, representing 4.5% of tested apricot samples. These samples, determined to be positive by tissue-printing hybridization, were also positive by reverse transcription-polymerase chain reaction (RT-PCR) (1). In addition, nucleotide sequences of the PCR products were obtained. The 'Bulida' isolate showed 100% homology to a Spanish isolate, apr9, while the 'Velkopavlovicka' isolate showed 99% homology to an Italian isolate. Since HSVd has not been previously reported in Canada (4), to our knowledge, this report documents its first detection in the country. This report may prompt the inclusion of regular testing for HSVd in existing Prunus spp. virus testing programs in Canada. References: (1) N. Astruc et al. Eur. J. Plant Pathol. 102:837, 1996. (2) M. Badenes et al. Acta Hortic. 472:565, 2001. (3) V. Pallás et al. Page 135 in: Virus and Virus-Like Diseases of Stone Fruits, with Particular Reference to the Mediterranean Region. A. Myrta et al., eds. CIHEAM-IAMB, 2003. (4) R. Singh et al. Page 255 in: Viroids. A. Hadidi et al., eds. CSIRO Publishing, Australia, 2003.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.000 |
| 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 teacher head, 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".