Diseases

Phoma stem canker of oilseed rape

Brassica napus var. napus

A fungal disease of oilseed rape caused by Leptosphaeria maculans and L. biglobosa, affecting all plant organs and capable of causing crop failure due to the destruction of the root collar.

In the reference 529 varieties crop Rapeseed, where this is mentioned in the description.

The pathogens of the disease are two fungal species: the more aggressive Leptosphaeria maculans and the less aggressive Leptosphaeria biglobosa, whose anamorph stage is known as Phoma lingam. The pathogen exhibits high genetic variability, manifesting in the presence of various pathotypes that differ in virulence.

The disease affects oilseed rape at all growth stages. Light spots with pycnidia appear on seedlings, and gray-brown spots with a dark margin appear on leaves. The most dangerous symptom is the formation of necrotic cankers at the stem base, which lead to tissue cracking, impaired nutrient uptake, and plant lodging.

Resistance of oilseed rape to Phoma stem canker includes qualitative resistance based on specific Rlm genes (e.g., Rlm4, Rlm7) that interact with the pathogen's avirulence genes. Quantitative polygenic resistance is also employed, aimed at slowing down the spread of infection in stem tissues and petioles.

General information about the subject — on the page Phoma rot.

Sources8

Varieties of Rapeseed mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.