Population structure and mating system in Marasmius androsaceus Fr.

Area of Science:

• Mycology
• Forest Ecology
• Population Genetics

Background:

• Marasmius androsaceus is a key rhizomorph-forming fungus in coniferous forest ecosystems.
• Understanding its population structure and interactions is crucial for forest health and nutrient cycling.

Purpose of the Study:

• To investigate the mating system and mycelial interactions of Marasmius androsaceus.
• To determine the spatial distribution and genet size of M. androsaceus in different forest stands.
• To explore the factors influencing the distribution patterns of this saprophytic fungus.

Main Methods:

• Collection of M. androsaceus isolates from Norway spruce and Scots pine stands of varying ages.
• Culturing isolates to study mating compatibility and mycelial antagonism.
• Genetic analysis to identify individual genets and assess their spatial distribution within plots.

Main Results:

• Marasmius androsaceus possesses a bifactorial mating system.
• Genetically distinct dikaryons showed strong mutual antagonism, allowing for the identification of up to 18 genets per 2.8 m².
• No significant differences in genet size were observed across the four study sites.
• Genets were often found in close proximity, excluding other types, with older plots showing discontinuous genet distribution.

Conclusions:

• Mycelial antagonism is a significant factor structuring M. androsaceus populations.
• The spatial distribution of genets is influenced by dispersal, establishment, and spread dynamics within woodland habitats.
• Age of the forest stand may impact the spatial arrangement of M. androsaceus genets.