生长素极性运输抑制剂(TIBA)对烟草离体花柄花芽分化的影响

在只含6-BA(2mg/L)的MS培养基上,烟草花柄外植体形态学基端膨大,上着生再生花芽,而花柄中部大多都形成愈伤组织。添加IAA(2,10,20 mg/L)后,花柄基端膨大的现象依然存在,但再生花芽的分布并不限于基端,在花柄中部、顶端都可见再生花芽。花柄外植体中部愈伤组织的形成也随添加的IAA和IAA浓度升高而受到抑制。在上述培养基中添加生长素极性运输抑制剂TIBA后,无一花柄中部能形成愈伤组织,再生花芽的形态变化也很大,有具锥形花柄的花芽、喇叭叶和一些难于确定由何种器官衍生而来的喇叭状器官。这些异于正常形态的器官发生,显然与花柄外植体中生长素极性运输受抑制有关,本文对它们的形成机理作了一些推测。

THE EFFECT OF TIBA ON THE FLORAL BUD DIFFERENTIATION FROM TOBACCO PEDICELS IN VITRO

The tobacco pedicels were cultured on the medium B2 (MS 6-BA 2mg/L), the morphological basal end of these pedicels swelled and regenerated floral buds. And it was observed that the calli were formed from the middle parts of some pedicels. IAA of different concentrations (2. 10, 20mg/L) was added into the medium mentioned above, the swelling basal ends of pedicels were still observed. But the distribution of neoformed floral buds was not limited on the basal ends, that is, the floral buds appeared on the middle parts of pedicels was inhibited with the increasing concentrations of IAA. TIBA, one of the auxin polar transport inhibitors, completely inhibited the callus formation from the middle parts of the pedicels, and led to the morphological changs of neoformed organs. We observed floral buds with taper-shaped pedicel, trumpet-shaped leaves, and trumpet-shaped organs whose original organs is unknown. In this paper, we present some suggestions on the machanism of the formaton of these abnormal shape organs.