mycoparasitism

Mycoparasitism is a form of parasitism in which a fungus obtains nutrients by feeding on another fungus. In nature, mycoparasitic interactions help regulate fungal populations in soil, on decaying plant material, and in the phyllosphere. Mycoparasites include fungi such as Trichoderma, Gliocladium, Ampelomyces quisqualis, and Coniothyrium minitans, among others. The host fungi are typically plant pathogens, though interactions with saprotrophic fungi also occur.

Mechanisms involve recognition and chemotaxis toward the host fungus, hyphal coiling around and penetration of the host, and enzymatic degradation of cell walls by chitinases, glucanases, and proteases. Mycoparasites may also secrete antifungal metabolites, compete for nutrients and space, and induce host cell death to access nutrients.

Ecologically, mycoparasitism contributes to disease suppression in soils and plant ecosystems. Practically, it underpins several commercial biological control products used in integrated pest management. Examples include Trichoderma species that antagonize Rhizoctonia and Botrytis, Ampelomyces quisqualis against powdery mildews, and Coniothyrium minitans that parasitizes Sclerotinia sclerotiorum sclerotia.

Limitations include variable efficacy due to environmental conditions, host range specificity, and production or formulation challenges. Regulatory and quality-control considerations apply to commercial biocontrol agents. Ongoing research seeks to understand host recognition signals and optimize strains for broad, sustainable disease suppression.