Diversity of symbiotic root endophytes of the Helotiales in ericaceous plants and the grass, Deschampsia flexuosa
Notice bibliographique
Résumé
In a study of fungi growing in various root-associated habitats in and around Picea mariana, black spruce, in northern Ontario, Canada, an examination was made of the degree to which differences in growth sites within an area of a few square kilometers might influence the structure of root-associated filamentous microfungal populations. Picea mariana roots were collected at four strongly differing boreal forest sites: an undisturbed forest site with deep litter and humus layers; a recently regenerated forest; a clearcut, former portable sawmill site with a few small, naturally regenerated trees; and an open peat bog penetrated by roots from trees growing along the margin. Comparisons were done on isolate assemblages primarily from serially washed mycorrhizae, supplemented with comparison samples from washed root bark and adherent rhizosphere soil. The Bray & Curtis similarity index and nodal components analysis were utilised to identify trends within the data. Root endophyte fungi, mainly Phialocephala fortinii and Meliniomyces variabilis, were among the most common isolates from serially washed mycorrhizae and showed strong trends among the site types, with the former most common from sites low in humus and also low in known humus-associated microfungi, and the latter most common from the peat bog site. The overall composition of the isolate assemblages from washed mycorrhizae mainly reflected site factors, with assemblages from the undisturbed and regenerated forest sites similar to one another and those from the clearcut and peat bog sites strongly distinct. A major difference was also seen between two seasonal samples at the exposed clearcut site, but few seasonal differences were seen at the other sites. The regenerated and undisturbed forest sites were high in Umbelopsis isabellina, Mortierella verticillata and Penicillium spinulosum, fungi typical of humic horizons in boreal podzols; the clearcut yielded the greatest numbers of Fusarium proliferatum, Umbelopsis nana and Penicillium montanense isolates, an assemblage tending to indicate exposed mineral soil; while the peat bog was typified by the presence of characteristic northern peat inhabitants Mortierella pulchella and P. spinulosum, as well as temperate peat inhabitant Penicillium lividum. A synthesis of these results with other data suggests that as a microhabitat, the mycorrhizosphere, as originally defined by Foster & Marks, is of little significance in determining the structure of filamentous fungal populations in soil influenced by the presence of ectomycorrhizal forest tree roots. Edaphic and overall microbial community conditions are much more significant, but the influence of a ¿symbiorhizosphere effect¿ exerted by certain ectomycorrhizal symbionts within the whole soil volume they occupy is also known in some cases and worthy of further investigation.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».