Isolation and regeneration of protoplasts from Porphyra dentata and Porphyra crispata

Large numbers of protoplasts (10⁶ to 3·2 × 10⁷ per gram fresh weight) were routinely isolated from two Taiwanese species of Porphyra: P. dentata and P. crispata. Intermediate and final forms of regeneration were observed, including swollen cells, monospore-like cells, filaments, callus-like structures and bladelets. Regeneration of leafy plants was achieved from protoplasts of P. crispata, whereas only conchocelis-like filaments were regenerated from protoplasts of P. dentata. In this latter species, conchosporangia and monosporangia appeared on the filaments upon cultivation at 25 °C. The variability in regenerative patterns is discussed.