细胞学观察发现，直接发生的营养芽和花芽起源于薄层组织的亚表皮细胞层。

Cytological study shows that the vegetative and floral buds originated directly from the subepidermal layers.

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以茎段、芽和叶片为材料，探讨了红千层愈伤组织诱导及植株再生的方法。

Taking stem segment, bud and leaf as materials, this paper made a study of callus induction and plant regeneration in Callistemon rigidus R.

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结论大鼠尾芽胚(第12 . 5天胚龄)视杯主要由未分化的细胞组成，视杯干细胞的分布集中在视杯内层和边缘层。

Conclusion optic cup of 12.5-embryonic-day-old rats composes of undifferentiated cells, and the stem cells are mainly located in optic cup inner and marginal.

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