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

Key Result

This project is still in progress, monitoring blackleg incidence and severity in selected commercial fields with different R-gene rotations and collecting information on blackleg avirulence gene changes in the growers’ fields in response to R-gene rotations.

Project Summary

Purpose

This study will monitor 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.

Progress

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.