Geotrichum citri-aurantii

Geotrichum citri-aurantii is a fungal species that belongs to the Geotrichum genus. It is known for causing the postharvest disease called sour rot in a variety of fruits, particularly citrus fruits such as oranges, lemons, and grapefruits.

Taxonomy

The species name citri-aurantii is derived from the Latin words citri, meaning citrus, and aurantii, meaning golden. This refers to the fungus's association with citrus fruits and its golden-yellow mycelium. The genus Geotrichum is part of the Saccharomycetales order in the Ascomycota phylum.

Description

Geotrichum citri-aurantii is a yeast-like fungus that forms white to cream-colored colonies. It produces conidia that are cylindrical or allantoid (sausage-shaped) and typically measures 8-15 x 2-4 µm. The conidia are borne on the ends of hyphae and are easily dislodged, aiding in the fungus's dispersal.

Pathology

Geotrichum citri-aurantii is a pathogen that causes sour rot, a postharvest disease that affects a wide range of fruits. The fungus enters the fruit through wounds or natural openings and produces enzymes that break down the fruit's tissues, resulting in a soft, watery rot. The decayed tissue often has a sour smell, hence the name of the disease.

Management

Control of Geotrichum citri-aurantii and sour rot involves a combination of preharvest and postharvest practices. These include proper irrigation and fertilization, regular inspection and removal of infected fruits, and postharvest treatments with fungicides or biocontrol agents.

See also

• List of citrus diseases
• Post-harvest losses (fruit and vegetables)