Grammothele

Grammothele is a genus of basidiomycete fungi within the Polyporaceae family, recognized as significant agents of white rot in woody plant tissues. By enzymatically degrading lignin, these fungi cause the structural degradation of dead or weakened timber, playing a complex role in forest ecosystems as decomposers.

The fungus primarily targets hardwood species, colonizing deadwood, stumps, and trees suffering from prior wounds or environmental stress. While often classified as saprotrophic, in horticultural settings, Grammothele can impact the health of mature or damaged trees, contributing to their premature decay and eventual decline.

The diagnostic signs of a Grammothele infection involve the emergence of thin, resupinate, or effused-reflex fruit bodies on the bark. These structures display a characteristic poroid or reticulate hymenophore. Internally, the wood becomes bleached, spongy, and brittle, indicating the total loss of cellular structural integrity.

Environmental conditions conducive to the spread of this pathogen include persistent high humidity, moderate temperatures (15-25°C), and stagnant air circulation. Spores are easily disseminated by wind and water, establishing colonies wherever moisture content within the woody tissue is sufficiently high to support mycelial growth.

The damage caused by Grammothele is mainly aesthetic and mechanical, as it compromises the stability of infected trees and degrades the value of timber. Management and control strategies focus on prevention:

• Implement systematic pruning to remove dead or diseased wood.
• Maintain high sanitary standards to reduce the total load of fungal spores in the area.
• Apply wound dressings or protective sealants to mechanical injuries on tree trunks.
• Ensure proper storage conditions for harvested wood, maintaining low humidity and good ventilation.