Discovery of Potato Rot Nematode, <i>Ditylenchus destructor</i>, Infesting Garlic in Ontario, Canada
Bibliographic record
Abstract
Potato rot nematode, Ditylenchus destructor Thorne, 1945, is a serious nematode pest in a number of root and tube crops, primarily in potatoes, and is an internationally quarantined pest (2). In garlic, it was only reported in Japan (3). In 2011, a survey was conducted for the stem and bulb nematode, Ditylenchus dipsaci (Kühn) Filipjev in Ontario, Canada. PCR analysis revealed that a population of Ditylenchus from one garlic (Allium sativum) bulb sample in a 0.81-ha field (2-acre) in the Ottawa area had a significantly longer ITS1 (approximately 100 bp) than that of D. dipsaci. Subsequent morphology and DNA sequencing concluded that the population was Ditylenchus destructor, a quarantine species in Canada. Twenty females and twenty males were fixed and permanently mounted for morphological studies. The main diagnostic characters matched the description of D. destructor by Thorne (4). The female stylets had strong knobs, 11.1 ± 0.9 (10 to 12) μm long, lateral fields with six distinct lines in the middle section of the body, excretory pore 4.7 ± 1.3 (3 to 6) μm posterior to the hemizonid, esophageal base bulb overlaps dorsally with the intestine, post-vulval uterine sac extends up to two-thirds of the vulva-anus distance, and tail terminus finely rounded. A total of 20 nematode individuals were used for the molecular studies. They had 5-bp differences with the ITS1 (GenBank Accession No. EF208210; 650 bp) sequence of an isolate from Sihong County, China. The sequence of the partial 18S gene (GenBank Accession No. AY593912; 864 bp) was identical to the sequence of an isolate of D. destructor in the Netherlands. The detection of stem and bulb nematode was also confirmed from the field. Infested garlic plants were stunted and the basal bulbs became dark and somewhat rotten. Prior to this finding in Canada, D. destructor was only reported in a few isolated locations in the province of Prince Edward Island (PEI) in 1946 (1). The nematodes in PEI were effectively controlled. Another suspected case in British Columbia was not confirmed since the infested field had been known to be infested with D. dipsaci. To our knowledge, this is the first report of D. destructor on the mainland of Canada. The infested field has been subjected to strict quarantine measures to prevent the spread of the pest. Reference: (1) A. D. Baker et al. Sci. Agric. 26:138, 1946. (2) EPPO. No. 123. Data Sheets on Quarantined Organisms. Bulletin OEPP/EPPO Bull. 8, 1978. (3) T. Fujimura et al. Jpn. J. Nematol. 8:22, 1989. (4) G. Thorne. Proc. Helminthol. Soc. Wash. 12:27, 1945.
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 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".