Study On Embryogenic Callus Induction Of Buxus Sinica Var. Parvifolia

Buxus sinica var. parvifolia which is an endemic tree of China, had high ornamental value, but it's in danger of extinction. The embryogenic callus induction of Buxus sinica var. parvifolia was studied to open up new areas of its efficient and rapid propagation.The result of research was as follows:1.The embryogenic callus induction of Buxus sinica var. parvifolia(1)The optimal explants of Buxus sinica var. parvifolia to induce callus was stem.The optimal method for the sterilization was 0.1%HgCl2 two minutes+2%84 four minutes and the empoison rate of stem was 23.26%.The optimal callus induction medium was 1.0mg·L-1 NAA+2.0mg·L-16-BA and the inductive rate was 69.84%.The best stem diameter was 1.2～1.6mm.The optimal subculture medium was 2mg·L-1 2,4-D+1mg·L-16-BA.(2)The optimal medium for inducing somatic embryogensis was 2mg·L-1NAA+1mg·L-1 2,4-D+0.2mg·L-1TDZ and the inductive rate was more than 52%,2,4-Dwas a necessary substance; In the suspension culture of embryogenic cell, the optimal rocking bed velocity was 95rmin-1,and the optimal combination was 0.2mg·L-1NAA +1mg·L-1TDZ; The best concentrate- on of sucrose was 45～55 g·L-1, and PEG was unfavorable to adjustment of embryogenic callus.(3)The ability of brown stain control of 2 g·L-1 active carbon was the best.2.Determination of the physiological and biochemical indices of callus in Buxus sinica var. parvifoliaThe level of soluble sugar, soluble protein and SOD activity was significantly higher in the embryogenic callus than that of non-embryogenic callus.3.Histological and cytological study on the callus of Buxus sinica var. parvifoliaUsing paraffin ethods, the proembryoes, the globular embryoes and the heart-shape embryoes were observed, but the following torpedo-shape embryoes and cotyledinous stage embryos were not found.