nematode egg-hatching inhibitory activity

traitmech:000723 · CLASS · PROPOSED

A physiological capability of a microorganism to reduce nematode egg hatching over a defined observation interval relative to comparable unexposed controls.

Trait evidence (2)

DOI:10.1163/156854104323072883
The least hatches were recorded in 7-day-old C. globosum (L250) filtrate, with 85 and 98% hatch reductions for SCN and RKN, respectively.

Meyer et al. 2004, Results, printed page 28/PDF page 6; all ten pages and actual Figure 1/Table 1 inspected. C. globosum is Chaetomium globosum; SCN and RKN are Heterodera glycines and Meloidogyne incognita. Native UNRESOLVED; Crossref and USDA verify identity. Typeset span matches; PDF extraction loses the fi ligature. Seven days is culture age, not egg exposure: hatch was scored after 14 days, including motile and immotile juveniles. Percent hatch uses initial eggs, then uninoculated PDB hatch as comparator; quoted reductions are relative to that control, not egg mortality. Biomass-free filtrate concentrations differ between hosts (75/90%); approximately 200 eggs per well, five wells per treatment, water viability control. Forty isolates were retested, not all 253. pH was measured, not neutralized; no identified active molecule or universal potency threshold is inferred.
DOI:10.1038/s41598-023-33669-z
T. asperellum FbMi6 inhibited egg hatching in all concentrations as compared to control.

Saharan et al. 2023, PMID:37088805, Results; direct publisher HTML match, native NOT_IN_ABSTRACT. This is its own experiment, not its background account of Meyer. Five surface-sterilized egg masses received spore-checked culture filtrates at 20/40/60/80%, with water and PDB controls; alternate-day counts through ten days, two repeats at 25 +/- 2 degrees C. Actual Figure 3 inspected. Results associates maximum inhibition with 120 h, whereas its legend specifies 2/4/6/8/10 days; no exact maximum/time pairing is adopted. Egg deformation does not prove death. Juvenile water-recovery findings are not transferred to eggs.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1163/156854104323072883

Parent traits (1)

phenotype METPO:1000059

kg-microbe context

No kg-microbe node embedding matched this record in the 2026-04-25 deepwalk.

Discussions and Knowledge Gaps (2)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Refine the hierarchy while preserving the microbial actor and hatching endpoint.

CURATION TODO OPEN nematode-egg-hatching-inhibition-scope-and-hierarchy · raised by codex · 2026-10-14

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

The microorganism has the inhibitory capability; this is not its own development or the nematode's susceptibility. Reduced hatching over an observed interval does not establish egg death, irreversible arrest or subsequent recovery. Juvenile paralysis or killing, fewer root egg masses, population suppression, trapping, attraction and sequence annotations alone are insufficient. Feeding and infection are not required. Related lethal, paralyzing, trapping, attracting and fungal-nematophagy records are not necessary parents; no organism-level disjointness is asserted. Phenotype METPO:1000059 is the conservative parent. Pinned/current METPO screening found only the unrelated fried-egg-shaped colony, not an exact active or deprecated counterpart in inspected owners; v599 proposes the class. Ovicidal terminology and nematicide chemical roles are not exact synonyms or xrefs. Neither a universal host/stage range nor a particular secretion mechanism is implied.

Resolve strain provenance and assay discrepancies before adding taxa or mechanisms.

KNOWLEDGE GAP OPEN nematode-egg-hatching-inhibition-source-and-mechanism-limits · raised by codex · 2026-10-14

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

Meyer's USDA technical abstract reports six motility-inhibitory isolates, versus four in the published paper; that separate endpoint is not silently reconciled. Saharan's claimed FbMi6 accession resolves to clone SF_570, while its supplement has SF_561/SF_570 and FbMi-4 inconsistencies documented in the lethal-nematicidal source assessment. Do not infer a corrected strain or canonical taxon. No shared active chemical, microbial protein, causal graph, field efficacy or environmental safety is asserted. Culture-filtrate effects do not define the entire class as secretion. Source hashes, direct quote checks and bounded notice checks are retained in the verification sidecar. Meyer has no Crossmark data available; no comprehensive notice clearance or full raw-data/statistical reanalysis is claimed.

Curation history

2026-10-14T03:09:57Z · MINTED_TRAITMECH_ID · codex
Added microbial nematode egg-hatching inhibitory activity with two DOI-backed primary studies and directly checked 22-word and 13-word result excerpts. Retained assay denominators, exposure intervals, source discrepancies and native UNRESOLVED/NOT_IN_ABSTRACT outcomes. Distinguished hatch reduction from egg death, paralysis and reduced reproduction. Reserved 000723, v599 and 1067600-1067699 after ignored/hidden current-copy, retained-history and open/draft PR checks; broad editor ranges are not competing reservations. No exact active METPO counterpart identified in inspected owners. Other records unchanged. Timestamp records observed acceptance, not the later file write.

Recorded curation sessions

2026-10-14T03:14:30Z · codex
- CREATE — Add nematode egg-hatching inhibitory activity
  Added one PROPOSED microbial capability reducing nematode egg hatching over a defined observation interval against comparable unexposed controls. Meyer 2004 is definition authority; Saharan 2023 supplies a second primary hatch experiment, not a background summary. Directly checked 22-word and 13-word excerpts retain native UNRESOLVED and NOT_IN_ABSTRACT outcomes. Preserved control denominators, culture-age versus exposure timing, source/figure discrepancies and strain-provenance limitations. No egg death, recovery, identified molecule, canonical taxon, exact synonym, xref or causal graph inferred. Ignored/hidden current-copy, retained-history and open/draft PR checks found no exact counterpart or competing allocation; broad editor envelopes are not narrower reservations. Local 000723, cohort v599 and full 1067600-1067699 block reserved. Trait timestamp records observed acceptance, while this history records later CREATE. Other records, including protected spore germination, remain unchanged.
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