Diseases

Phoma stem canker of rapeseed

Brassica napus L.

A fungal disease of rapeseed caused by Leptosphaeria maculans and L. biglobosa, characterized by damage to stems, root collars, and seedlings. The disease leads to lodging, premature wilting, and impairment of the plant's vascular system.

In the reference 215 varieties crop Rapeseed, where this is mentioned in the description.

The disease is caused by two fungal species: the highly aggressive Leptosphaeria maculans and the less aggressive L. biglobosa. Symptoms appear at all growth stages: from the emergence of water-soaked spots with pycnidia on cotyledons and hypocotyls, which lead to seedling death, to the formation of necrosis, ulcers, and cracking in the lower part of the stem of adult plants.

Genetic protection against phoma stem canker is based on two types of resistance. Monogenic resistance is provided by specific Rlm genes that recognize pathogen avirulence genes, although their efficacy may decrease due to the high variability of the fungus. Polygenic resistance, which restricts the development of necrosis in petioles and stems, is a more stable mechanism and is often combined with monogenic genes in modern breeding programs.

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.