Pycnospore

Pycnospore is a term used in mycology to describe a type of asexual spore produced within a pycnidium. Pycnidia are small, flask-shaped or globose fruiting bodies that contain numerous conidiophores, which are specialized hyphae that bear the conidia. These conidia are the pycnospores.

Pycnospores are typically unicellular and are released from the pycnidium through a pore or ostiole. Their primary function is asexual reproduction and dispersal, allowing the fungus to spread to new environments. The morphology of pycnospores can vary greatly between different fungal species, with differences in size, shape, color, and septation. These characteristics are often used in fungal identification.

Pycnospores are commonly found in fungi belonging to the Ascomycota, particularly those in the orders Sphaeriales and Dothideales. They play a significant role in the life cycle of many plant-pathogenic fungi, contributing to the development and spread of diseases. The release of pycnospores can be triggered by environmental factors such as moisture and temperature. Upon dispersal, if conditions are favorable, pycnospores can germinate and initiate new infections.