GROWTH AND ULTRASTRUCTURE OF SPHAGNUM FIMBRIATUM CULTURED WITH ARSENATE, FLUORIDE, MERCURY AND COPPER IONS

Abstract

  The tolerance of Sphagnum fimbriatum Wils. towards some inorganic pollutants (As, F, Hg and Cu) was studied in long-term aseptic laboratory cultures. Only slight or no growth-retarding effect was found when Hg²⁺, Cu²⁺ or F^- were given at a low concentration (10^-2 and 10^-3 mM) but arsenate strongly inhibited development even in 10^-2 mM solution. Fluoride and copper ions proved to be the least poisonous of these substances but all of them were nearly or quite lethal at a concentration of 1 mM. The cytopathological features seen in plants grown in sublethal concentrations were fairly characteristic of the substances tested, showing that they disturb different metabolic pathways in the cells. Both arsenate and copper stimulated synthesis of starch in the chloroplasts. Mercury and fluoride promoted lipid accumulation in the spherosomes and chloroplasts. High concentrations of arsenate and fluoride disturbed the differentiation of hyaline cells. The physiological effects of these substances are discussed with special reference to the problem of pollution.