Mycophagous Amoeboid Organisms From Soil that Perforate Spores of Thielaviopsis basicola and Cochliobolus sativus

Abstract

Direct visual evidence in laboratory culture chambers showed that certain free-living, soil-inhabiting, amoeboid organisms perforated and fed on chlamydospores and mycelia of T. basicola and conidia of C. sativus. The annulations and performations of fungal spores observed in the culture chambers were similar to those found in spores incubated in field soils obtained from various locations in Canada. The systematic position of the mycophagous amoebae seems to be with the protozoan order Proteomyxida and the family Vampyrellidae, but species identification cannot be made with certainty because the taxonomy is still controversial. Based on their widespread distribution in arable soils and their marked predacious activity it is postulated that the mycophagous soil amoebae may play a significant role in the ecology of soil-borne fungal plant pathogens and their biological control.