Induction and Suspension Culture of Calluses from Polygonatum odoratum

Effects of hormone, carbon source, and pH on induction, as well as that of hormone on proliferation of callus tissues from Polygonatum odoratum were studied. Rhizomes and leaves of the plants were used as the explants in the experiment. In addition, the suspension culture for propagating the callus cells was optimized. The results showed that the optimal medium for the induction of rhizome and leaf calluses was MS+1.0 mg 6-BAL-1+0.5 mg NAAL-1+30% sucrose at pH 5.6. The optimal hormone combination for the callus proliferation was 1.5 mg 6-BAL-1 and 0.6 mg NAAL-1. The rates of callus induction and proliferation of the rhizomes were significantly higher than those of the leaves. For the suspension culture on rhizome callus cells, the optimum inoculum rate was 60 gL-1, and the hormone combination of 1.5 mg 6-BAL-1+0.6 mg NAAL-1. The growth and polysaccharide content of the cells in the suspension exhibited an S-shape curve with an optimal subculture cycle of 16 d. The polysaccharide content in the cells peaked after 14 d cultivation, while the pH of the medium decreased initially followed by an increase, and leveled off subsequently.