Growth and carrageenan content of Kappaphycus striatus micropropagules in semi-natural and natural conditions

Abstract

 In this study, in vitro 8-week-old micropropagules of K. striatus were grown in semi-natural and natural conditions to evaluate the growth, development, and carrageenan content of the Seaweed. At the semi-natural conditions, in vitro 8-week-old micropropagules of K. striatus (8 branches plant, 3.01 cm in height, and 1.23 g in fresh weight) under natural light reduced to 1/2 light intensity by using a blue-black net (250 µmol m^-2 s^-1), showed higher survival rate, fresh weight, and growth rate than under other lighting conditions (fluorescent lamp and natural light) after 8 weeks of culture. Then, seaweed was grown in the field in Van Phong bay (Khanh Hoa province) by the floating method. The results showed that the growth (5.25-fold of fresh and dry weight; 4.42-fold of growth rate) and carrageenan content (28.83%) of in vitro seaweed were higher than those of the natural seaweed after 10 weeks of culture. This study demonstrated that the growth and carrageenan content of K. striatus was improved by the in vitro culture method.