Distribution of mycotoxins and usnic acid in the thalli of epigeous lichens

The distribution of mycotoxins and usnic acid in the thallus of epigeous fruticose lichens Alectoria ochroleuca; several species of the genera Cladonia, Cetraria, and Flavocetraria; foliose lichens Nephroma arcticum; and six species of the genus Peltigera were studied by enzyme-linked immunosorbent assay. The mycotoxin content was lower in the top or apical parts of the thalli than in the basal parts and in dead areas. Differences in the distribution of usnic acid were insignificant in the majority of species, but in Cladonia stellaris and N. arcticum lichens the content of this metabolite in the upper and peripheral areas was higher than in the basal parts.