Gracilaria sp. is one of the main species collected for agar production in Brazil nowadays. The aim of this work was to compare the in vitro growth of different reproductive phases of wild specimens (reddish) and a color strain (light green) of Gracilaria sp., when cultivated in two culture media: Von Stosch and Provasoli. Six strains were selected: reddish (rd) and light green (lg) gametophytes, both female (F) and male (M); reddish tetrasporophytes, but obtained from different crosses, Frd x Mrd and Flg x Mrd. The growth rates, which were analysed for 28 days, were calculated using fresh mass (mGR) and length (lGR). The light green strain showed lower mGR and lGR than the reddish specimens. The growth was satisfatory in both culture media for wild strains. Reddish and light green male gametophytes and reddish tetrasporophytes showed higher mGR and lGR when cultivated in Provasoli. Light green female gametophytes showed similar mGR in both culture media, but the lGR were higher in Von Stosch. The IGR of tetrasporophytes derived from crosses Frd x Mrd were higher than the tetrasporophytes derived from Flg x Mrd.
Gracilaria; growth; color strain; reproductive stage; culture medium
