First Report of Pink Seed of Common Bean Caused by <i>Erwinia rhapontici</i>
Bibliographic record
Abstract
In 2001, a new disease of common bean (Phaseolus vulgaris L.) caused by Erwinia rhapontici (Millard) Burkh. was detected in seed samples from southern Alberta, Canada. Infected seeds had pink or pinkish-brown lesions on the seed coat. The disease was found in great northern (cv. US1140), pink (cv. Viva), and pinto (cv. Othello) beans at low (<0.1%) frequencies. Isolation from surface-sterilized pink seeds resulted in bacterial cultures, which produced a water-soluble pink pigment on potato dextrose agar (PDA). Seven isolates were tested for physiological characteristics using conventional tests (1) and API 50CHE test strips (bioMérieux Canada, St. Laurent, Quebec), and tested for cellular fatty acids using the MIDI system (Newark, DE). All isolates were gram-negative, motile, facultative anaerobic rods with mucoid colonies and produced a pink pigment on PDA. They were positive for citrate utilization, catalase, methyl red, and Voges-Proskauer, and negative for arginine dihydrolase, lysine and ornithine decarboxylases, urease, gelatin liquification, indole production, oxidase, and gas production. Fatty acid profiles matched with E. rhapontici (approximately 30% each 16:0 and 16:1 ω7c/15:0 iso 2OH; 12% 18:1 ω7c: 8% each 17:0 cyclo and 14:0 3OH/16:1 iso; 4 to 5% each 12:0 and 14:0). Isolates were positive for acid production from: N-acetyl glucosamine, l-arabinose, amygdalin, arbutin, cellobiose, esculin (hydrolysis), d-fructose, d-fucose, d-galactose, β-gentiobiose, d-glucose, glycerol, i-myo-inositol, lactose, maltose, d-mannitol, d-mannose, melibiose, d-raffinose, l-rhamnose, ribose, salicin, d-sorbitol, sucrose, trehalose, and d-xylose. These results match published results for E. rhapontici (4). For pathogenicity tests, each isolate was inoculated in 30 pods from six bean plants (cv. US1140) as described for pink seed of peas (2). Each pod was inoculated with 0.1 ml of bacterial suspension, approximately 10 9 CFU/ml, by injection through the mid-rib at the basal end. The same number of uninoculated and water-inoculated pods served as controls. Plants were kept in the greenhouse (20 ± 5°C) for 4 weeks, after which isolations were done as described above. In duplicate experiments, all isolates caused lesions on pods extending up to 5 cm from the inoculation point with corresponding discoloration of seeds. The frequency of infected seeds varied among isolates, ranging from 20 to 50%. E. rhapontici was reisolated from seeds with lesions, but not asymptomatic seeds. The study concludes that pink seed of common bean is due to E. rhapontici, a pathogen previously reported on peas in Alberta, Canada (2), and Montana (3). References: (1) D. J. Brenner. Bergey's Manual of Systematic Bacteriology, vol.1, Williams and Wilkens, Baltimore, MD, 1984. (2) H. C. Huang et al. Can. J. Plant Pathol. 12:445, 1990. (3) B. K. Schroeder et al. Plant Dis. 86:188, 2002. (4) L. Verdonck et al. Int. J. Syst. Bacteriol. 37:4, 1987.
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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".