Ustilago segetum

Ustilago segetum is a species of fungus in the family Ustilaginaceae. It is commonly known as the loose smut of barley and is a significant plant pathogen, particularly affecting barley crops.

Taxonomy

The species was first described scientifically by Christiaan Hendrik Persoon in 1801. It belongs to the genus Ustilago, which comprises around 200 species of plant-pathogenic fungi.

Description

Ustilago segetum is characterized by its ability to infect the inflorescence of barley plants, causing a condition known as smut. The fungus replaces the grains of the barley with its own spores, which are dark and powdery, giving the infected plant a 'smutted' appearance.

Life cycle

The life cycle of Ustilago segetum involves both sexual and asexual stages. The fungus overwinters in the soil as teliospores, which germinate in the spring to produce basidiospores. These basidiospores infect the barley plant, leading to the production of more teliospores in the infected grains.

Economic impact

As a plant pathogen, Ustilago segetum can have a significant economic impact on barley crops. The fungus reduces the yield and quality of the grain, leading to financial losses for farmers. Control measures include the use of resistant barley varieties and fungicides.

See also

• List of barley diseases
• Ustilago maydis
• Ustilago nuda