Axenic cultures of Hypnea musciformis (Wulfen) Lamouroux were established in Provasoli (PES) solid medium with different agar concentrations (0.4%, 0.6%, 0.8% e 1.0%) to evaluate their effects on callus growth and plant regeneration. The cultures in solid medium induced the growth of four types of callus (apical - CApi, lateral 1 - CLat1, lateral 2 - CLat2, and basal - CBas), which consist of pigmented and unisseriate proliferations. The type CApi was the most frequent (rate of 5.3 calli per explant at 1.0% of agar). The highest biomass of regenerated plantlets (7.4 g) was obtained from calli cultured at 1.0% of agar. The growth of the four types of calli is reported for the first time, and indicates that different agar concentrations in the medium induce morphogenetic effects on callus growth and regeneration of apical segments in H. musciformis.
agar effects; axenic culture; callus; Hypnea musciformis; Rhodophyta
