Diseases

Verticillium Wilt of Hop

Humulus lupulus L.

A fungal vascular disease of hops caused by the pathogens Verticillium nonalfalfae and V. dahliae, which blocks water transport and leads to plant death.

In the reference 35 varieties crop Common hop, where this is mentioned in the description.

The primary causative agents of the disease are Verticillium nonalfalfae, responsible for lethal outbreaks, and Verticillium dahliae. Pathogens are classified by virulence into mild and lethal strains, as well as specific pathotypes such as PV1 and the highly virulent PV3, which is capable of overcoming the resistance of many cultivars.

Symptoms appear after flowering as a loss of turgor, yellowing and curling of leaves, and blackening of stems with characteristic thickening at heights up to one and a half meters. A cross-section of the stem reveals browning of the vascular system, caused by the occlusion of the xylem by fungal mycelium.

Breeding for resistance to Verticillium wilt is based not on simple genes, but on the identification of quantitative trait loci (QTLs) and molecular markers, such as those associated with WAK-kinases. Cultivar resistance is determined by the results of field trials in infected plots, as new pathotypes are capable of negating the accumulated resistance potential.

General information about the subject — on the page Verticillium wilt.

Sources8

Varieties of Common hop 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.