Boeremia exigua

Species of fungus

Boeremia exigua is a species of fungus in the family Didymellaceae. It is a plant pathogen known to cause disease in a wide range of host plants. This fungus is of particular interest in agriculture due to its impact on crop yield and quality.

Taxonomy

Boeremia exigua was originally described as part of the genus Phoma, but subsequent phylogenetic studies have led to its reclassification into the genus Boeremia. This reclassification was based on molecular data that provided a clearer understanding of the relationships within the Didymellaceae family.

Morphology

Phoma spores at 160X magnification

The fungus produces conidia that are typically ellipsoidal to cylindrical in shape. These conidia are produced in pycnidia, which are asexual fruiting bodies that appear as small, black structures on the surface of infected plant tissue. The spores are dispersed by water and wind, facilitating the spread of the pathogen.

Life Cycle

Boeremia exigua has a complex life cycle that includes both sexual and asexual stages. The asexual stage is characterized by the production of conidia, while the sexual stage involves the formation of ascospores within pseudothecia. The fungus can survive in plant debris, which serves as a source of inoculum for new infections.

Host Range

This pathogen has a broad host range, affecting numerous plant species including potatoes, tomatoes, and various legumes. It is particularly notorious for causing blackleg and stem canker in potatoes, leading to significant economic losses.

Symptoms

Infected plants exhibit a variety of symptoms depending on the host species and environmental conditions. Common symptoms include leaf spots, stem lesions, and fruit rot. These symptoms can lead to reduced photosynthetic capacity and overall plant vigor.

Management

Managing Boeremia exigua involves a combination of cultural practices, chemical control, and the use of resistant varieties. Cultural practices such as crop rotation and removal of infected plant debris can help reduce the inoculum in the field. Fungicides may be used, but their effectiveness can vary depending on the timing and method of application.

Research

Ongoing research aims to better understand the genetic diversity of Boeremia exigua populations and their interactions with host plants. This research is crucial for developing effective management strategies and breeding programs for resistant crop varieties.

Related pages

• Phoma
• Plant pathology
• Fungal diseases of plants