Diplodia corticola


Diplodia corticola, Commonly known as bot canker of oak; is a species of anamorphic fungus in the family Botryosphaeriaceae, an asexual stage of  Botryosphaeria corticola. A fungus with both sexual and asexual reproductive cycles. Members of the Botryosphaeriaceae family are widely known as destructive pathogens of woody plants, including economically important crops grown for human consumption. They infect a wide range of fruit and nut trees, such as almonds, as well as various forest species.

Secondary Metabolites

Known metabolites include sphaeropsidins B and C, -mellein, and sapinofuranone B. Diplodia corticola also produces a range of secondary metabolites, including a newly identified compound, diplopyrone C, a 5,6-dihydropyran-2-one derivative. The fungus also synthesizes sphaeropsidin A, a pimarane diterpene known for its antimicrobial, herbicidal, and insecticidal properties.

Geographic Distribution

Diplodia corticola is broadly distributed across the Mediterranean regions of Europe, as well as in North Africa and parts of North America, including Tennessee and several Mid-Atlantic states.

Pathology

Diplodia corticola primarily affects oak trees, causing symptoms such as dieback, cankers, and vascular discoloration. It is considered a pathogen that infects trees that have been weakened by environmental stressors such as climatic, biological and chemical stressors or previous diseases. Recent studies have highlighted its involvement in oak decline in regions such as Tennessee, United States of America, where it was identified as the causative agent of dieback in Quercus alba which are sources of significant ecological and commercial values in eastern North America.
Infected red and white oak species by diplodia corticola includes:
The fungus causes several symptoms, including crown thinning, where the leaves become pale, smaller, and a decrease in numbers. Bark bleeding and cracking occur, characterized by dark stains and oozing lesions on the trunk. As well as, cankers and dieback, leading to the death of affected branches. Lastly, wood discoloration.