FUNGITOXICANTS AND FUNGAL TAXONOMY

Certain chemicals are selectively toxic to specific groups of fungi. For example, benzimidazoles and thiophanates are selectively toxic to Ascomycotina and Deuteromycotina, oxathiins are selectively toxic to Basidiomycotina, and pyrimidines, polyenes, and polyoxins are toxic to many fungi but not Mastigomycotina. Chemicals selectively toxic to Mastigomycotina include fenaminosulf and prothiocarb. Such chemicals contribute to fungal taxonomy in several ways. Incorporated into isolation media they facilitate the recovery of specific groups of fungi from natural habitats. In some cases the distinctive response of a fungus to a specific chemical facilitates identification of the fungus. Arrangements based on sensitivity to selective fungitoxicants often match classifications based on morphological characters. Selectivity data then provide opportunities to assess the naturalness of established or experimental classifications, to demonstrate the predictive power of classifications or to show the ability of alternative classifications to accommodate apparent exceptions. Selective fungitoxicants also contribute to chemotaxonomy of fungi in two major ways. Fungi can be partitioned into groups on the basis of their responses to an external chemical and research on the mechanisms of action of selective fungitoxicants provides information on the comparative biochemistry of fungi. © 1979 The New York Botanical Garden.