| Autor: |
Tonu NN; Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2, Canada., Wen R; Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2, Canada., Song T; Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2, Canada., Guo X; Pest Surveillance Initiative, 5A-1325 Markham Road, Winnipeg, MB R3T 4J6, Canada., Murphy LA; Pest Surveillance Initiative, 5A-1325 Markham Road, Winnipeg, MB R3T 4J6, Canada., Gossen BD; Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2, Canada., Yu F; Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2, Canada., Peng G; Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2, Canada. |
| Abstrakt: |
Genetic resistance is a cornerstone for managing clubroot ( Plasmodiophora brassicae ). However, when used repeatedly, a clubroot resistance (CR) gene can be broken rapidly. In this study, canola inbred/hybrid lines carrying one or two CR genes ( Rcr1/CRa M and Crr1 rutb ) were assessed against P. brassicae pathotype X by repeated exposure to the same inoculum source under a controlled environment. Lines carrying two CR genes, either Rcr1 + Crr1 rutb or CRa M + Crr1 rutb , showed partial resistance. Selected lines were inoculated with a field pathotype X population (L-G3) at 5 × 10 6 resting spores/g soil, and all clubs were returned to the soil they came from six weeks after inoculation. The planting was repeated for five cycles, with diseased roots being returned to the soil after each cycle. The soil inoculum was quantified using qPCR before each planting cycle. All lines with a single CR gene were consistently susceptible, maintaining high soil inoculum levels over time. The lines carrying two CR genes showed much lower clubroot severity, resulting in a 10-fold decline in soil inoculum. These results showed that the CR-gene stacking provided moderate resistance against P . brassicae pathotype X, which may also help reduce the pathogen inoculum buildup in soil. |
