Ultrastructure and Lipid Composition of Mosses

Abstract

Some moss gametophores, after fixation for EM, show strong accumulation of osmium in cytoplasmic droplets. The droplets are numerous in gametophores of Ceratodon purpureus (Hedw.) Brid., Tortula ruralis (Hedw.) Gaertn., Mayer et Scherb. and Hypnum curvifolium Hedw.; there are fewer in Mnium cuspidatum Hedw.; there are none in M. punctatum Hedw. var. elatum Schimp. and Hygrohypnum luridum (Hedw.) Jenn. Lipid analyses of these gametophores showed a correlation between the amount of triglycerides with the occurrence of cytoplasmic droplets. The same correlation was encountered within a species. Cultures of C. purpureus had numerous cytoplasmic droplets when the triglyceride content was high, but had few when the triglyceride level was low.