Factors influencing Plasmodiophora brassicae resting spore loads in soil and clubroot disease severity in canola (Brassica napus)
Notice bibliographique
Résumé
Clubroot, caused by Plasmodiophora brassicae, is an important soilborne disease of Brassica napus canola. Studies were conducted to increase understanding of the impact of various soil parameters and crop rotation regimes on P. brassicae inoculum levels and clubroot severity, respectively. In one study, the concentration of pathogen resting spores was assessed in 284 soil samples, collected from three clubroot-infested fields (Bassano, Edmonton, and Parkland County, Alberta), by quantitative PCR analysis. The samples also were analyzed for soil organic matter content, electrical conductivity, pH, and boron and calcium concentrations. Data analysis based on the P. brassicae-positive samples pooled from the three fields indicated that resting spore concentration was positively correlated with soil organic matter (r2 =0.51, P <0.0001, N = 127), calcium (r2 =0.44, P <0.0001, N = 127) and boron concentration (r2 =0.11, P <0.0001, N = 127), but negatively correlated with soil pH (r2 =0.09, P = 0.0004, N = 127) and electrical conductivity (r2 =0.23, P <0.0001, N = 127), respectively. These correlations, while significant, were generally weak and suggest that other factors, such as cropping history, may affect resting spore concentrations in the soil. In a second study, the effects of six crop rotation regimes on clubroot severity were evaluated under greenhouse conditions. Rotations included: T1) continuous cropping of a clubroot-susceptible canola cultivar (S); T2) S –fallow (F) - S – F - S; T3) S – barley (B) - S – B – S; T4) S – resistant canola cultivar (R) - S – R – S; T5) continuous cropping of the same resistant cultivar; and T6) continuous cropping of different clubroot resistant canola cultivars. Index of disease (ID) was recorded along with other plant growth parameters for the canola at the end of each cycle of a rotation. When galled root tissue collected from a treatment was incorporated back into the soil, the average ID of the susceptible canola cultivar included in T1 to T4 increased significantly (p ≤ 0.05) from 93.1 % (after the first crop cycle) to 99.6 % (after the fifth crop cycle). The ID of the resistant canola cultivar included in T5 also increased significantly from 12.5 % to 22.3 %. In contrast, when different clubroot resistant canola cultivars were grown in succession in T6, the average ID decreased significantly from 12.5 % to 9.4 % (after the fifth cycle). The data suggest some erosion of resistance after continuous cropping of the same resistant cultivar, which was not observed when different resistant cultivars were rotated.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| 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 | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 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 tête enseignante, 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 ».