verticillum

Verticillum is a genus of fungi belonging to the family Mycocentrospora. These fungi are known for their role as plant pathogens, particularly causing wilting diseases in a variety of agricultural and ornamental crops. The most well-known species within this genus is Verticillium dahliae, which is responsible for significant economic losses in crops such as cotton, potatoes, tomatoes, and many others.

The characteristic symptom of Verticillium wilt is a unilateral wilting of leaves, often starting on one side of a plant or even a single leaf. This is due to the fungus colonizing the plant's vascular system, specifically the xylem. Once inside the xylem, the fungal hyphae grow and produce spores, which can block water transport, leading to the wilting symptoms. Discoloration of the vascular tissue, often appearing as streaks, can also be observed when the stem is cut.

Verticillium fungi are soil-borne and can survive for extended periods in the soil as dormant structures called microsclerotia. These microsclerotia can be spread through contaminated soil, water, or plant debris. Infection typically occurs when plant roots come into contact with these microsclerotia, which then germinate and penetrate the root tissues.

Management of Verticillium wilt is challenging due to the persistence of the pathogen in the soil. Strategies include crop rotation with non-host plants, using resistant cultivars, improving soil drainage, and maintaining good field sanitation to prevent the spread of infested material. There are no effective chemical treatments to cure plants once infected.