邓恩桉快繁再生体系建立及褐化现象的消除

Rapid Propagation Regeneration System and Elimination of Browning for Eucalyptus dunnii Maiden

为解决邓恩桉组培中芽增殖率低及继代中褐化现象严重的问题,以邓恩桉9年生优良母株新萌发枝条为外植体所建立的无菌苗为对象,研究了腋芽分化产生丛生芽过程所需的最适激素条件及继代过程中褐化现象的消除方法。结果表明：以改良MS培养基为基本培养,附加TDZ0．5~1．0mg/L有助于邓恩桉初代丛生芽的诱导；培养基中含TDZ 0．5mg/L、 NAA0．3mg/L时,芽继代增殖倍数可达6．2倍。芽丛继代中褐化现象减轻的最适条件为：材料继代接种后先在黑暗下培养4~6d,然后移入光下培养25d,同时继代培养基添加硫辛酸35mg/L,芽增殖系数可达10．2,褐化率降为3．7%。生根培养基以1/2MS 为基本培养基,附加 ABT 生根粉0．75mg/L＋IBA0．25mg/L的组合生根率最高,达91．5%。

For dealing with the lower bud proliferation s and serious browning phenome of its subculture during tis-sue culture of Eucalyptus dunnii Maiden, the optimal conditions for lateral bud differentiation and browning elimi-nation methods were studied by using aseptic seedling based on new branch from excellent maternal plant with 9 years old as explant. The results showed that the modified Murashigeane and Skoog （ MS） medium with TDZ 0. 5~1. 0mg/L could facilitate the induction of cluster bud, and buds proliferation of its subculture achieved to 6. 2 times with TDZ 0. 5mg/L＆amp;NAA 0. 3 mg /L. The optimal conditions for browning elimination were 4-6 days’ cul-ture under darkness after inoculation of subculture, and then 25 days’ culture under light. The bud proliferation rose to 10. 2 and the explants browning rate dropped to 3. 7% when the subculture medium supplemented alpha li-poic acid with 35 mg/L. 91. 5% rooting rate was achieved in 1/2 modified MS medium with ABT rooting powder 0. 5mg/L, IBA0. 25mg/L.