Improving blackleg resistance durability through R-gene rotation in commercial fields on the Canadian Prairies: a science-based stewardship program

Project Summary

This study monitors blackleg incidence and severity in selected commercial fields with different R-gene rotations. This will develop empirical data of blackleg avirulence gene changes in the growers’ fields in response to R-gene rotations.

Trials

Westar (No R gene), var (E1 (Rlm4)), 6090RR (AC (LepR3/Rlm3), and CS2400 (CX (Rlm3/RlmX) were set as non-rotation control in year 2020. A new variety with Rlm2 was introduced to the rotation with the canola varieties CS2400 and 74-44BL from year 2019. Susceptible canola variety Westar showed the highest disease incidence (99.3 per cent) and severity (4.13) in Manitoba. The new introduced Rlm2 showed the lowest disease incidence (36.5 per cent) when rotated with the canola variety 74-44BL (2019). Also, it showed lower disease incidence (64.5 per cent) when rotated with the canola variety CS2400 (2019). Similarly, the Rlm2 plots displayed lower disease severity values (1.44-1.78). Plots seeded to the same canola variety without R gene rotations showed both higher disease incidence and severity.

Results

Canola cultivars rotated with new resistant genes showed good performance in reducing the disease incidence and severity. Rlm4 (alone) or Rlm4 in combination with other R-genes showed lower disease severity and incidence.

Related publications

1. Sustainability on the farm: breeding for resistance and management of major canola diseases in Canada contributing towards an IPM approach
2. Validating the strategic deployment of blackleg resistance gene groups in commercial canola fields on the Canadian Prairies
3. Genomic variations and mutational events associated with plant–pathogen interactions
4. The wonderful world of intrinsic and intricate immunity responses in plants against pathogens