Abstract: Effects of basal media, carbon-source, nitrogen-source and extracts of potato or banana on polysaccharides synthesis of protocorm-like bodies (PLBs) of Dendrobium huoshanense were investigated. Among eight basal media including full- and half- strength of MS, B5, N6 and SH, 1/2Ms and N6 were most suitable for the synthesis of polysaccharides, and the polysaccharide yield reached 479.47mg/L and 417.05mg/L after subculturing for 30d, respectively. For carbon source, it was better in using 30g/ L glucose rather than sucrose and fructose. Under the suitable concentration, the influence of different kinds of nitrogen source on polysaccharide yields was not so big. The optimized nitrogen was at 10mmol/L, while more nitrogen would inhibit the synthesis of polysaccharide. In addition, the addition of extracts of potato (100g/L) or banana (100g/L) to the basal MS medium has benefited the polysaccharide yield.

Key words: Dendrobium huoshanense, protocorm-like bodies (PLBs), liquid culture, polysaccharides