Study on Browning Controlling of Magnolia sieboldii in Tissue Culture

Factors affecting browning problem of Magnolia sieboldii K.Koch including type of explants,pre-treatment of explants,medium,anti-browning substances and culture conditions were studied.The results showed that B5 medium could prevent the explants from browning well while browning was serious on MS medium.The type of explant played an important role in browning.The browning rate of lateral bud was the lowest,followed by terminal bud;and the browning rate of the stem with bud was the highest.Soaking explants in 1 g/L VC for 4 h could alleviate browning effectively.Browning could be restrained by adding antioxidant and absorbent at appropriate concentrationn in the medium B5+0.5 mg/L 6-BA+0.3 mg/L IBA.The anti-browning effect ranked as PVPVCAC.Low temperature and dark cultivation at the early stage of cultivation could relieve the browning problem.