Toxic effects of the thallus of the lichen Cladonia foliacea on the growth and morphogenesis of bryophytes

In this paper the effects induced by the whole thallus of the lichen Cladonia foliacea on the growth and development of some mosses (Funaria hygrometrica, Bryum dunense, Pleurchaete squarrosa) and the liverwort Lunularia cruciata, have been studied. The main effects induced by Cladonia thalli during periods of co-existence in vitro with gametophytes is a delay in the regeneration of new filaments asssociated with the inhibition of their growth together with a global decrement in the number of gametophores. Other alterations at cytoplasm level are a granular appearance of cytoplasm and many microvesicles in the newly-regenerated filaments, enlarged periplasmic space and changes in chloroplast shape. Current results are compared to previous data obtained with pure substances isolated from C. foliacea thalli. (C) ADAC / Elsevier, Paris.