INDUCED FLUORESCENCE IN GAMETOPHYTES OF SOME LAMINARIALES

Abstract

The effectiveness of fluorescence microscopy in cytological studies of some Laminariales in culture has been demonstrated in preliminary experiments. Gametophytes were initiated and grown for several weeks in culture media containing different fluorescent compounds. In addition, culture slides were removed from control dishes at different developmental stages and vitally stained with fluorescent media for periods up to 48 hours. Acridine orange and coriphosphine selectively stained the nuclei and cytoplasm in vivo. However, acridine orange had to be applied in the dark, and applications of both fluors were limited to relatively short staining periods since they were toxic to the cultures after 48 hours. Calcofluor White and Biofluor fluorescent brighteners, particularly Calcofluor White PMS, were highly successful. They were (i) non-toxic to the cultures, (ii) selectively absorbed by the cell walls quickly and permanently, (iii) intensely fluorescent at pH 7.8, (iv) stable, and (v) transported to subsequent gametophytic growth. Actively growing regions of the gametophytes fluoresced most brightly, while reproductive and sporophytic cells absorbed the brighteners very weakly. Possible applications of the brighteners in cytological, genetical, developmental, and ecological studies of the marine algae are suggested.