Post-release monitoring of genetically modified canola (Brassica napus L.) in western Canada: escape, persistence and spread of novel traits
Notice bibliographique
Résumé
Genetically modified (GM) canola (Brassica napus L.) has been widely adopted in Canada since its commercial release in 1995 and now represents over 85% of the canola grown in western Canada. Concurrently, GM canola volunteers have become an increasing management problem in cultivated fields and are ubiquitous in adjacent ruderal (non-cropped disturbed) habitats. However, systematic post-release monitoring is lacking and the ecological and agronomic impacts of escaped GM canola are poorly understood. In this dissertation, I characterize the escape, demography and distribution of GM canola in ruderal habitats in southern Manitoba, at multiple spatial and temporal scales. I characterized GM herbicide tolerance traits in 16 escaped canola populations. The progeny of 129 plants were tested in herbicide trials; 74% of plants produced glyphosate-tolerant progeny, 63% produced glufosinate-tolerant progeny, and 34% produced multiple herbicide-tolerant progeny as a result of gene flow between escaped plants. At the population-scale, four escaped GM canola populations were monitored and periodic matrix models were constructed to describe the dynamics and persistence of flowering plants. Escaped populations were observed to flower in synchrony with adjacent crops and were projected to persist for 2 to 5 years, confirming the potential for gene flow between escaped and cultivated canola populations. At the landscape-scale, the distribution of escaped canola was surveyed in three agricultural regions. Regional factors were important determinants of distribution; escaped canola density was positively correlated with canola cropping intensity and with traffic intensity, and was negatively correlated with distance to grain distribution centres. Local seed dispersal had negligible impact on distribution compared to landscape-scale anthropogenic seed inputs resulting from agricultural transport. These findings suggest that escaped canola persists as a metapopulation, where long-distance dispersal and colonization compensate for frequent extinction of local populations. Escaped populations play an important role in the persistence and spread of GM traits at large spatial scales, with substantial implications for the coexistence of GM and non-GM crops, and especially for organic and reduced-tillage farming operations. Landscape-scale management approaches, designed and implemented collaboratively by multiple stakeholders, are necessary to mitigate the risks of contamination resulting from GM trait escape. Regulation and ongoing monitoring of GM crops must acknowledge and address the dynamic regional nature of seed- and pollen-mediated gene flow.
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 ».