First report of downy mildew caused by <i>Peronospora chlorae</i> on lisianthus in Turkey
Bibliographic record
Abstract
Lisianthus (Eustoma grandiflorum), also known as Texas bluebell, belongs to the family Gentianaceae. Lisianthus is a cut flower crop and is grown as an annual in İzmir, Turkey where greenhouse production exceeded 4 million plants produced from an area of 5.6 hectares in 2016 (Tüik, 1). In June 2017, plants showing severe downy mildew symptoms were observed in greenhouses in Menderes province. Under wet conditions, infected leaves turned yellow or pale green, with a greyish to brownish fungal-like downy growth developing on both the abaxial and adaxial leaf surface (Fig. 1). Leaf defoliation occurred at high disease severity and the remaining leaves withered. Infected leaves were collected for microscopic examination and morphological identification. A layer of sporangiophores was observed on symptomatic leaves, characteristic of a downy mildew. Sporangiophores were hyaline with long straight trunks and ended with two slightly curved branchlets. The sporangiophores were 200-480 × 4-11 μm. Sporangia were ovoid and hyaline, and measured 14-20 × 14-18 μm (Fig. 2). The pathogen was identified as Peronospora chlorae based on morphological characteristics (Hall, 2). DNA analysis was performed to confirm the identity of the pathogen. The internal transcribed spacer (ITS) region of rDNA was amplified and sequenced with primers ITS1 and ITS4 (White et al., 3) and the sequence was submitted to GenBank (Accession No. MG711454). A BLASTn analysis showed 100% identity to P. chlorae (KT271839), confirming the identity of the pathogen. For pathogenicity testing, infected leaves were collected and sporangia were washed from the diseased leaves with sterile water. Pathogenicity tests were performed by spraying lisianthus seedlings with the conidial suspension. Plants were then covered with plastic bags and incubated at 22-24°C with 90% relative humidity. Seven days post inoculation, sporangiophores were observed on infected lisianthus plants while no symptoms were observed on control plants. Peronospora chlorae has been previously reported from Denmark, France, Hungary, Italy, The Netherlands, Norway, Poland, Portugal, Spain, Switzerland, Ukraine, United Kingdom, the former Yugoslavia, Canada, Mexico, and China (Yang et al., 4). To our knowledge, this is the first report of P. chlorae causing downy mildew on lisianthus in Turkey.
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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) | 0.001 | 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 | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".