INVITRO MYCELIAL INTERACTIONS AMONG MEMBERS OF A SOIL MICROFUNGAL COMMUNITY

In vitro interactions among seven members of a soil microfungal community were examined and characterized to provide information on how interactions may influence fungal community structure in soil. Behaviors of species in paired culture was observed on three media with different nutrient resources (malt, dilute cornmeal and water agar) in Petri dishes and on microscope slides. All isolates used in this study were in some way affected by the presence of another fungus; usually growth was inhibited. Outcomes of mycelial interactions after growth for 4 weeks or more were categorized as: (1) neutral intermingling, (2) deadlock and (3) replacement. Deadlock, in which neither mycelium can enter territory occupied by the other, was the most commonly observed outcome of the pairings except on low-resource media, where neutral intermingling was the commonest class of interaction. Our results suggest that fungal community structure under oligotrophic conditions is not highly territorial, but mycelia become more territorial and combative when colonizing relatively resource-rich microhabitats or substrates.