Verticillium wilt

A plant disease caused by soil-borne fungi

Verticillium wilt is a fungal disease affecting over 300 species of eudicot plants. It is caused by fungi in the genus Verticillium, primarily Verticillium dahliae and Verticillium albo-atrum. The disease is characterized by wilting, chlorosis, and necrosis of leaves, often leading to plant death.

Symptoms

Plants infected with Verticillium wilt exhibit a range of symptoms, including yellowing and wilting of leaves, stunted growth, and premature leaf drop. The vascular tissue of affected plants often shows brown discoloration, which can be observed by cutting through the stem.

Pathogen

The fungi responsible for Verticillium wilt are soil-borne and can persist in the soil for many years. Verticillium dahliae produces microsclerotia, which are small, resilient structures that allow the fungus to survive in the absence of a host. These microsclerotia germinate in response to root exudates from susceptible plants.

Host Range

Verticillium wilt affects a wide range of host plants, including economically important crops such as tomato, potato, cotton, and olive. Many ornamental plants, such as maple and rose, are also susceptible.

Disease Cycle

The disease cycle of Verticillium wilt begins with the germination of microsclerotia in the soil. The fungus infects the plant through the roots and colonizes the vascular system, disrupting water and nutrient transport. This leads to the characteristic wilting and yellowing symptoms.

Management

Management of Verticillium wilt involves a combination of cultural practices, resistant varieties, and, in some cases, chemical treatments. Crop rotation and soil solarization can help reduce the inoculum in the soil. Resistant cultivars are available for some crops, and these should be used where possible.

Images

Symptoms of Verticillium wilt on a plant.

Verticillium dahliae microsclerotia.

A tree showing symptoms of Verticillium wilt.

Related pages

• Fusarium wilt
• Phytophthora
• Plant pathology

References

• Pegg, G. F., & Brady, B. L. (2002). Verticillium Wilts. CABI Publishing.
• Agrios, G. N. (2005). Plant Pathology. Elsevier Academic Press.