Effects of plant growth regulators and culture medium on morphogenesis of Solieria filiformis (Rhodophyta) cultured in vitro

Morphogenesis and plant regeneration were analyzed in axenic tissueculture of the red alga Solieria filiformis (Kützing)Gabrielson. Thallus segments cultured in ASP 12-NTA synthetic medium showedgrowth of filaments formed by divisions of cortical, subcortical and medullarycells (filamentous explants), whereas in seawater enriched with Von Stosch'ssolution, thallus segments developed branches. Filamentous explants were abletoregenerate plants when transferred from a solid to a liquid medium. Plantregeneration was significantly promoted by treatment with plant growthregulators on filamentous explants formed from intercalary segments, up to 67plantlets per explant in treatments with 6-benzylaminopurine (5.0 mgl^–1), in contrast to three plantlets in controlslackingplant growth regulators. These adventitious plantlets developed into plantsmorphologically similar to those originated from germinating spores. Theseresults indicate that plant growth regulators play a role on the regulation ofmorphogenesis, and could be useful for micropropagation of colloid-producingredalgae.