Deightoniella torulosa

Deightoniella torulosa is a species of fungus that belongs to the family Botryosphaeriaceae. It is a plant pathogen that causes a disease known as black spot in rubber trees (Hevea brasiliensis). The fungus is also known to infect other plant species, including grapevines and apple trees.

Taxonomy

The fungus was first described in 1916 by British mycologist John Ramsbottom. It was initially classified in the genus Diplodia, but was later moved to the genus Deightoniella based on its morphological characteristics.

Description

Deightoniella torulosa is characterized by its dark brown to black spores, which are typically oval in shape and measure 25-30 x 10-15 µm. The fungus produces pycnidia, which are flask-shaped structures that contain the spores. The pycnidia are initially white, but turn black as they mature.

Pathogenicity

Deightoniella torulosa is a necrotrophic pathogen, meaning it kills the host tissue and then feeds on the dead material. The fungus enters the plant through wounds or natural openings, such as stomata. Once inside the plant, it produces toxins that kill the host cells. The dead tissue then serves as a nutrient source for the fungus.

Management

Control of Deightoniella torulosa involves a combination of cultural practices and chemical treatments. Cultural practices include pruning and removing infected plant material to reduce the amount of inoculum in the environment. Chemical treatments typically involve the use of fungicides.

See also

• List of grape diseases
• List of apple diseases