XVI International Botanical Congess

Axenic cultures of Gracilariopsis tenuifrons (Gracilariales, Rhodophyta) were established in ASP 12-NTA solid medium (0.4% agar and 1.0% sucrose)supplemented with indole-3-acetic acid (IAA), 2,4-dichlorophenoxyacetic acid (2,4-D), and 6-benzylaminopurine (BA). Calluses were originated from divisions of apical and cortical cells located at apical regions of thallus segments and branches. Low concentration of IAA (0.5 mg/L) enhanced callus induction, while IAA:BA (1.0:1.0 mg/L) or 2,4-D (0.5 mg/L) stimulated the callus growth. Regeneration of plantlets from calluses was stimulated by BA. These results suggest that auxin and cytokinin are involved in developmental regulatory processes in red algae.