First report of ‘<i>Candidatus</i> Phytoplasma trifolii’ (group 16SrVI) infecting <i>Sauropus androgynus</i>
Bibliographic record
Abstract
Sauropus androgynus, also known as sweet leaf, cekur manis, asin-asin and pak waan, is a shrub grown in some tropical regions as a leaf vegetable.It is one of the most popular leaf vegetables in South and Southeast Asia and is notable for high yields and palatability. During October 2010, plants of S. androgynus growing in small plots in the area of Poring Springs, Sabah, Malaysia, were noted showing proliferations of miniature leaves (reduced laminar and petiole length) at the apex of the plant emerging from cut stems where the plants had previously been harvested. Symptoms were observed in around 50% of the S. androgynus plants surveyed. Plants showing these symptoms were tested for phytoplasma. Leaf samples from S. androgynus (from five plants with and two plants without symptoms) were collected, and total DNA extracted (FastDNA Spin Kit, MP Biomedicals, USA). Phytoplasma universal primers specific for 16S rDNA (R16mF2/R1 and R16F2n/R2; Gundersen & Lee, 1996) were used in a nested PCR assay. Nested PCR products of expected size (~1250 bp) were obtained for all the S. androgynus plants showing symptoms. Symptomless plants yielded no PCR products. Amplicons were purified (Wizard PCR Clean-up, Promega) and sequenced bi-directionally (University of Health Network, Toronto, Ontario, Canada). The partial 16S rDNA sequence obtained was deposited in GenBank (Accession No. HQ121242). BLAST analysis showed that the16S rDNA sequence of S. androgynus phytoplasma was 99% identical to those of the group 16SrVI, ‘Candidatus Phytoplasma trifolii’. Restriction fragment length polymorphism analysis (RFLP) of amplicons using AluI and RsaI yielded profiles similar to those of the 16SrVI-A phytoplasma subgroup. Phytoplasmas of group 16SrVI have mainly been reported in North America and Europe (IRPCM, 2004; Přibylová et al., 2008). In South Asia, 16SrVI phytoplasmas have been recently associated with diseases in other perennial herbaceous hosts, including Calotropis gigantean and Portulaca grandiflora (Priya et al., 2010). However, to our knowledge, this is the first world report of a 16SrVI-related phytoplasma infecting S. androgynus, which may represent a phytosanitary risk for other herbaceous perennial crops in the region.The National Plant Protection Organisation (NPPO) of Malaysia has been notified of these matters.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".