Sporidial mating and infection process of the smut fungus,<i>Ustilago hordei</i>, in susceptible barley
Bibliographic record
Abstract
Ustilago hordei (Pers.) Lagerh. causes covered smut of barley and oats. Sporidial mating and the infection process on compatible barley plants, cv. Hannchen, were investigated using light microscopy and scanning and transmission electron microscopy. Within 2 h after mixing of sporidia of opposite mating types on water agar, polar conjugation tubes emerged that subsequently fused, producing infection hyphae at the junctions. Similar events occurred on germinated barley shoots, although sporidia regularly produced several conjugation tubes, of which only one was involved in mating. Tubes emerging from the sides of cells were also observed. Infection hyphae emerged from either the conjugation tube or conjugated cell body. Hyphae elongated along the shoot surface until characteristic crook and appressorium-like structures were formed. An invading hypha emerged beneath this structure and directly penetrated the underlying epidermal cell. Hyphae extended both intra- and inter-cellularly into tissues, without much branching, before becoming established in the shoot meristematic region. Plant plasma membranes remained intact during pathogen ingress and an electron-dense matrix of unknown origin appeared in the interface between plant plasma membrane and invading hypha. A large fungal biomass was generated in the host spike tissue at 4263 days postinoculation during the development of the floral meristem.Key words: Hordeum vulgare, pathogen, sporidia, teliospores, ultrastructure, Ustilaginales.
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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 | 0.000 | 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) | 0.001 | 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".