Diseases

Alternaria Leaf Spot of Rapeseed

Brassica napus L.

A fungal disease of rapeseed affecting all above-ground plant organs throughout the entire growing season. It is caused by fungal species of the genus Alternaria, leading to pod deformation and reduced seed quality.

In the reference 49 varieties crop Rapeseed, where this is mentioned in the description.

The primary pathogens of rapeseed Alternaria leaf spot are the fungi Alternaria brassicae, Alternaria brassicicola, and, less frequently, Alternaria alternata and Alternaria raphani. The disease manifests on leaves as circular or angular spots with concentric zonation or a yellow halo. Sunken dark lesions form on stems and pods, leading to premature pod shattering, trident-shaped deformation of the valves, and the shedding of underdeveloped seeds.

Unlike other rapeseed pathogens, no specific resistance genes or stable pathogen races have been described for Alternaria leaf spot. Protection is based on the use of quantitative resistance and field tolerance. Potential defense factors are associated with the expression of genes encoding chitinases and glucanases; however, breeding remains focused on evaluating samples under field conditions.

General information about the subject — on the page Alternaria blight.

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.