DEVELOPMENT OF A MEDIUM AND CULTURE SYSTEM FOR IN-VITRO PROPAGATION OF THE SEAGRASS HALOPHILA-ENGELMANNII

An in vitro culture system was developed for axenic culture of the seagrass Halophila engelmannii Aschers. The culture system had a rhizome layer solidified with agar (0.8% w/v) and a liquid overlay layer. The rhizome layer contained artificial seawater (20 parts per thousand, inorganic nutrients, plant growth regulators, sucrose (1% w/v), and activated charcoal (1% w/v). The overlay layer contained artificial seawater and inorganic nutrients. The medium f/4 provided the best source of inorganic nutrients of the five media compared. Axenic cultures of H. engelmannii died if NO3 was the only N source. They grew best when supplied with glutamic acid at a concentration of 3.4 mM as the N source. A combination of alpha-naphthaleneacetic acid at a concentration of 0.25 mg.L(-1) and 6-benzylaminopurine at a concentration of 10 mg.L(-1) provided the most rapid rates of propagation as measured by the numbers of pseudowhorls and branches produced.