THE EFFECTS OF GLYCEROL AND PLANT-GROWTH REGULATORS ON GRACILARIA-VERRUCOSA (GIGARTINALES, RHODOPHYCEAE)

Callus induction of the agarophyte marine alga Gracilaria verrucosa wa s obtained on modified ASP6 F2 media. The formation of callus from axe nic explants depended on the addition of glycerol (0.217 mol l-1) and plant growth regulators (2.0 mg l-1 IPA, 2.0 mg l-1 IAA, and 1.0 mg l- 1 2iP). Glycerol alone, did not induce callus. The addition of 5.0 mg l-1 DPU (Diphenylurea) caused callus induction on the whole surface of the explants of Gracilaria verrucosa. Different culture-media, carbon sources and phytohormones were tested. The application of floridoside (2-O-D-glycerol-alpha-D-galactopyranoside), the main product of photo synthesis of the red algae, did not promote growth and callus inductio n.