Drechslera tritici-repentis

Drechslera tritici-repentis is a fungal pathogen that causes tan spot, a common disease in wheat crops. It is a member of the Pleosporaceae family and the Drechslera genus. The pathogen is known for its ability to cause significant yield losses in wheat crops, particularly in regions with a temperate climate.

Taxonomy

The fungus was first described in 1923 by Drechsler, who named it Helminthosporium tritici-repentis. It was later reclassified into the Drechslera genus based on its conidial morphology. The current accepted name is Drechslera tritici-repentis.

Description

Drechslera tritici-repentis is a filamentous fungus that produces multicellular, darkly pigmented conidia. The conidia are typically curved and have a distinctive "cigar" shape. The fungus is heterothallic, meaning it requires two compatible mating types for sexual reproduction.

Pathogenicity

Drechslera tritici-repentis is the causal agent of tan spot in wheat. The disease is characterized by the formation of necrotic lesions on the leaves, surrounded by a yellow halo. The pathogen produces a host-specific toxin, known as Ptr ToxA, which is responsible for the necrosis and chlorosis observed in infected plants.

Management

Management of tan spot and Drechslera tritici-repentis involves a combination of cultural practices, chemical control, and the use of resistant wheat varieties. Crop rotation and residue management can help reduce the amount of inoculum in the field. Fungicides can also be used to control the disease, although resistance to certain fungicides has been reported.

See also

• Tan spot
• Drechslera
• Pleosporaceae