Diseases

Fusarium Wilt of Onion

Allium cepa L. var. cepa

Fusarium wilt of onion is a disease caused by the specialized fungus Fusarium oxysporum f. sp. cepae, manifesting as basal rot followed by plant wilting and leaf yellowing.

In the reference 96 varieties crop Onion, where this is mentioned in the description.

The primary pathogen is Fusarium oxysporum f. sp. cepae, although the pathocomplex may include other Fusarium species such as F. acuminatum, F. solani, and F. culmorum. Infection development is facilitated by high humidity and temperatures in the range of +22…+27°С, as well as damage to the basal plate by pests, such as the onion fly.

During the growing season, the disease manifests as yellowing and twisting of leaf tips, along with necrosis and dieback of the root system. Abundant white or pinkish mycelium forms on the bulbs, and the tissues of the basal plate soften and become watery. The aggressiveness of the pathogen is linked to the presence of specific effector genes, including the SIX9 gene.

Breeding for resistance is based on the evaluation of lines under infectious backgrounds and the identification of parental forms. Currently, there is no universally accepted letter-coding system for resistance genes to this disease in onions.

General information about the subject — on the page Fusarium wilt and blight.

Sources8

Varieties of Onion 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.