Dimargaritomycetes

Dimargaritomycetes are a class of fungi belonging to the subphylum Kickxellomycotina, which primarily function as obligate mycoparasites. In agricultural terms, they are not direct pathogens of plants but play a significant role in the soil microbiome by interacting with other fungi. These organisms rely entirely on their hosts to complete their biological cycle, making them specialized regulators of fungal communities in the field.

The causative agents are fungi with septate mycelia that produce characteristic dichotomously branched sporangiophores. The type of interaction is defined as mycoparasitism. They predominantly attack other fungi, including various zygomycetes and other fungal species found in the rhizosphere that may otherwise cause root rots or other plant diseases if their populations are not kept in check.

Symptoms of their activity are typically not visible on the plant itself, but rather on the fungal colonies they parasitize. These signs include stunted growth, shriveling of host hyphae, and a complete cessation of the host fungus's reproductive cycle. Through these mechanisms, Dimargaritomycetes can effectively suppress the colonization of plant tissues by harmful pathogenic fungi.

Environmental conditions for their growth involve high moisture levels and a sufficient concentration of host fungi in the soil. They thrive in environments rich in organic matter, which supports a diverse array of microfungi. Spore dispersal is facilitated by water movement, soil moisture, and to some extent, soil-dwelling insects or larger soil organisms that act as vectors within the rhizosphere.

Their economic impact is generally viewed as beneficial or neutral, as they act as natural biocontrol agents by limiting the spread of other fungal pathogens. Therefore, no specific protective measures against them are required. Agronomic practices focused on soil health, such as balanced fertilization and proper moisture management, inherently create a balanced environment where these natural fungal antagonists can function effectively.