Tissue Culture And Rapid-propagation In Torreya Grandis

This paper studied tissue culture and rapid-propagation of Torreya grandis. Through callus induction, multiple shoots and axillary bud induction and subsequent subculture, plantlets were obtained at last.Various explants have different callus induction rate. From leaf, bud and shoot 81.7%, 79.8%, 84.2% callus was inducted. Callus from leaf and bud was not stable and couldn' t proliferate on subsequent subculture due to browing which leaded to its death. The callus from shoot was sub-cultured on B₅ medium supplemented with 0.1-0.5mg/L 6-BA and 0.1-0. 5mg/L 2, 4-D.There are many factors effect the callus induction from shoot, for example, variety, time of sampling, manner of culture and so on .During of the shoot culture , more callus was produced with male plant as explant than female plant.It was observed that activated carbon not only effectively control the browing problem but also have a good effect on the callus subculture and proliferation. With the addition of 0. 8% activated carbon prevented calli browing.After several subculture of the callus from shoot, it was changed into B₅ medium supplemented with 0. 1 mg/L 6-BA and 2. 0 mg/L NAA for 20 days, then multiple shoots turned up and can keep on growing on appropriate medium.The axillary bud can be inducted on B₅ medium supplemented with KT 0. 1mg/L and NAA 2. 0mg/L. The highest frequencies was 144%, and the axillary bud grew well.Plantlets were obtained from multiple shoots and axillary buds. The plant with only one root from somatic embryos can form many roots on 1/4B5 medium supplemented with BA 0.1mg/L and IBA 0. 5mg/L. This research will establish a base for the genetic transformation and improvement of Torreya grandis in the future.