Effect of different seedling sources on growth and carrageenan yield of seaweed kappaphycus alvarezii cultivated in Marobo Waters, Muna Regency, Southeast (Se) Sulawesi, Indonesia

Abstract The purpose of this study was to determine the effect of different seedling sources on growth and carrageenan yield of K. alvarezii. There were three various seedlings sources used in this study: local strain, tissue-cultured seedlings, and seedlings resulting from mass selection combined with tissue–cultured method called “prof’. This research was over three months (August-October 2018) in Marobo coastal waters, Bone District, Muna Regency SE Sulawesi using the longline method. The results showed that the daily growth rate (DGR) during this study tended to fluctuate among treatments “prof’ and tissue-cultured seedlings had higher the DGRs than local strain seedlings. Ratio fresh weight (FW) and dry weight (DW) showed no significant differences among different seedling sources. The mean FW: DW ratio showed the local strain had the highest ratio (10.10:1) followed by tissue-cultured seedlings (9.88:1) and prof (9.06:1). Furthermore, the local strain showed a significant difference in carrageenan yield from the “prof’ and tissue-culture seedlings. Local strain seedlings showed the highest carrageenan yield (40.58±2.51%) followed by tissue-cultured seedling (35.35±2.79%) and prof seedlings (33.88±2.09%). Ice-ice disease and epiphyte (Sargassum polychystum) were found during this study. This study showed that prof and tissue-cultured seedlings greater potential for improved seaweed farming.