Grafting of Kappaphycus alvarezii seedlings using different seedling sources in Sasara Coastal Waters, Buton Utara, Southeast (SE) Sulawesi, Indonesia

Abstract

Combining local seaweed thalli with tissue culture seedlings through grafting has been suggested as way to improve seaweed Kappaphycus alvarezii seedling quality. The purpose of this study was to investigate the growth of K. alvarezzi seedlings produced from a combination of three seedling sources using a straight connection grafting method. We applied the grafting method using local and tissue-cultured seedlings. The trials took place in the coastal waters of Sasara, Buton Utara, SE Sulawesi, Indonesia from January to April 2019. The grafting combinations were: tissue culture and local; tissue culture and tissue culture; and local with local. The bonding period for all combinations was 9 days after the initial insertion and the success rate was 91.66-93.33%. The grafted seedlings were then cultured for 45 days using a longline technique. The water temperature, salinity, and nitrate and phosphate concentrations affected grafting success. The salinity range was 29-33 ppt and water temperature was 28-32 C. Nitrate and phosphate ranges were 0.263-0.463 mg.L-1 and 0.112-0.218mg.L-1, respectively; turbidity was 1.59-2.35 NTU. The highest daily growth rate was obtained from the grafting of tissue cultured and local strain seedlings (6.51 0.340%.day-1) whereas growth rate was lowest for the local with local grafts (5.76 0.378%.day-1).