First Report of the Root-Lesion Nematode, <i>Pratylenchus alleni</i> Associated with Damage on Soybean in Quebec, Canada
Bibliographic record
Abstract
In eastern Canada, soybean, Glycine max (L.) Merr., is the most important cultivated legume species. In 2011, the provinces of Ontario and Quebec had 987,400 and 300,000 ha of soybean production, respectively. Root-lesion nematodes, Pratylenchus spp., are the most prevalent plant-parasitic nematodes in Canadian agroecosystems and can affect many crops (3). In 2011, irregular patches of stunted soybean plants were observed for the first time in a 10-ha soybean field grown on a light texture soil in St. Anicet, Quebec (45°4'50.51″N, 74°21'18.56″W). Yield reduction in damaged plots ranged from 38 to 54% when compared with asymptomatic adjacent plots. The field was sown with soybean cv. PRO 2715R (PRO Seeds of Canada, Woodstock, ON), a Roundup Ready cultivar of 2,750 CHU, at 100 kg/ha. Soil analysis revealed a uniform pH of 6.0 ± 0.2 on a gravelly sandy soil (81% sand, 10% loam, 9% clay, and 4% organic matter). On 7 October 2011, root samples were collected from 10 randomly selected damaged patches, washed under running water, and deposited in a mist chamber for a 14-day extraction period. Specimens were stored in tap water at 4°C before identification. Based on morphological characteristics, 26 individual specimens were examined (14 females, 11 males, one juvenile) and were all identified as Pratylenchus alleni Ferris, 1961 (2). Genomic DNA was extracted from individual larvae and the internal transcribed spacers (ITS) region was amplified. RFLP analysis with five restriction enzymes (CfoI, DdeI, HindIII, HpaII, and PstI) showed that the banding pattern for this species was different from those of 18 other major Pratylenchus species (4). Sequence of ITS regions of this population (GenBank Accession No. JX081545) confirmed genus identification but showed only limited homology (<85%) with the 20 Pratylenchus species available in the database at this time. Based on the morphological identification and the ITS sequence divergence with other important species, the sequence was deposited as the first P. alleni accession in GenBank. In the United States, the pathogenicity of P. alleni to soybean is well established (1). To our knowledge, this is the first report of P. alleni occurrence and damage to soybean in Canada. The outbreak of this root-lesion nematode will pose a new challenge for crop management since no registered compounds are currently available against this pest in soybean in Canada. References: (1) N. Acosta and R. B. Malek. J. Nematol. 13:6, 1981. (2) V. Ferris. Proc. Helminthological Soc. Washington 28:109, 1961. (3) J. W. Potter and A. W. McKeown. Can. J. Soil Sci. 83:289, 2003. (4) L. Waeyenberge et al. Nematol. 2:135, 2000.
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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".