黑荆的茎尖培养和植株再生

试验以黑荆实生幼苗的茎尖作外植体,利用MS改良配方作基本培养基,补加不同种类和浓度的激素,分析了影响黑荆组培中诱导增殖和生根阶段的主要因素,摸索出各阶段的最适培养基,成功地培养出根系完整的黑荆试管苗并移栽成活。结果表明:(1)诱导增殖阶段的主要影响因素是分裂素浓度,在一定范围内,浓度越高,增殖率也越高,但不定芽伸长生长减缓;(2)影响生根的因素有无机盐浓度、分裂素浓度及生长素浓度,其中分裂素抑制生根,低盐浓度培养基有较高生根率;生长素在一定范围内促进生根,超过一定浓度时抑制生根。

Studies on the Plant Regeneration of Acacia mearnsii by Stem Tip Culture

The experiment was performed by using stem tips of black wattle(Acacia mearnsii willd.) seedlings as the explants and adopting MS improvedformulation as the basic culture media supplemented with different kinds andconcentrations of hormones. The main factors affecting the multiplication induc-tion and rooting were analysed in the tissue culture of A.mearnsii, the optimummedia in various stages were searched out and the tube plantlets with completeroots were successfully cultured and transplanted to the nursery.The resultsshow that: (1) the main factor affecting multiplication induction is the concentra-tion of cytokinins. The higher the concentration of cytokinins, the higher is themultiplication rate within a definite range. And (2) the factors affecting rootinginclude the concentrations of inorganic salts, cytokinins and auxins.Among thesefactors, cytokinins may inhibit rooting, higher rooting rates occur in the culturemedia with lower salt concentrations and auxins can promote rooting within acertain range.