邓恩桉组培中影响继代增殖条件的研究

A Study on Factors Affecting Clump Shoot Induction in Tissue Culture of Eucalyptue Dunnii

探讨抗寒树种邓恩桉组培快繁中影响其继代培养的因素。实验表明，继代培养以改良MS为基本培养基，随继代次数的增加逐渐减少细胞分裂素BA和生长素NAA的浓度。最初几次继代，BA的浓度为0．5mg／L，NAA的浓度为0．2mg／L。然后BA的浓度逐渐降低到0．1-0，3mg／L，NAA的浓度逐渐降至0．05-0．1mg／L，继代5—6次后，BA的浓度保持在0．1-0．3mg／L，NAA的浓度保持在0．05-0．1mg/L。继代周期随季节而不同，夏季为15—25d，春秋季为20，35d，冬季为4J0～50d，芽的月增殖系数为3—5倍，满足工厂化育苗的要求。组培苗的玻璃化和遗传变异等异常现象很少，节间长度适中，有利于生根。

The factors that affect clump shoots induction in tissue culture of Eucalyptue dunnli were discussed in this paper. The appropriate basic medium for subculture of E, dunnii was the amended MS, and the concentration of hormone BA and NAA should be reduced with the increment of subculture generation. The suitable concentrations of BA and NAA were 0.5 mg/L and 0. 2 mg/L respectively at the initial stage of subculture, then gradually reduced from 0.1 to 0.3 mg/L and from 0.05 to 0.1 mg/L respectively during the followed several generations, and kept on 0.3 mg/L and 0.1 rng/L respectively after 5 - 6 generations. The subculture period varied with seasons, 15 -25d in Summer, 20 - 35d in Spring and Autumn, and 40 - 50d in winter. The monthly multiplication coefficient of shoots varied from 3 to 6 times which could meet the demands of factory production. The vitrification of plantlet was rarely exhibited in this experiment. These plantlets could be easily transplanted because of the optimal bud burls length.