Odontotrema

Odontotrema is a genus of ascomycetous fungi known to cause bark diseases in various woody plants. These fungi typically function as saprotrophs or weak parasites, colonizing the surface or inner layers of the bark, which can lead to localized necrosis and long-term damage to tree health if the host is already weakened by environmental stressors.

The disease is classified under necrotic bark disorders. The pathogen infects the tree through bark fissures, wounds, or frost cracks. Once established, the fungal mycelium invades the cortical tissues and cambium, disrupting nutrient transport and creating favorable conditions for the formation of cankers and ulcerous lesions on the surface of branches and trunks.

This pathogen primarily affects deciduous trees and some coniferous species. The susceptibility of these plants is often linked to factors such as drought, nutrient deficiency, or mechanical injuries. In forest ecosystems, the presence of Odontotrema can indicate an overall decline in stand vitality, particularly in areas with high humidity and poor aeration.

Symptoms are identified by the presence of small, disk-shaped or cup-shaped fruiting bodies called apothecia on the bark. Surrounding tissues often exhibit discoloration, cracking, and peeling. If left unchecked, the progressive death of bark tissue can result in the dieback of branches, severely compromising the physiological state of the host plant.

Development and spread are facilitated by prolonged periods of humidity and favorable temperatures, which allow fungal spores to disperse via rain splashes or wind. Preventive measures rely heavily on silvicultural practices, including the systematic removal of infected deadwood, ensuring proper spacing between trees to improve air circulation, and protecting tree trunks from mechanical trauma to reduce entry points for the pathogen.