烟草薄层培养早期细胞核形态与核DNA含量变化的研究

通过应用ＤＮＡ专一性活体荧光染色剂Ｈｏｅｃｈｅｓｔ３３２５８对烟草茎表皮细胞薄层培养物的细胞核进行活体染色，发现在培养早期，细胞核发生了明显变化，由分化时的一般扁圆形和靠壁的位置逐渐变成圆形和居中的位置；核体积增大；染色质结构由致密变得疏松；而后染色质凝缩，发生无丝分裂；经数次分裂之后，细胞形态较一致，通过单细胞核内ＤＮＡ含量的测定，发现细胞分裂之前，核ＤＮＡ含量不增加；而最初几次分裂之后，含量减

Changes of nuclear shape and DNA content of tobacco cells in the early stage of thin layer culture

The live nuclei of the cultured tobacco epidermal cells were stained with Hoechest 33258. They changed conspicuously during the early stage of cell culture. The nuclei became round out of the ordinary oblate shapes,while they moved into the center part from the periphery of the cells. Their volumes enlarged,and chromatin became loosen. Later on, the chromatin was condensed. Finally,the cells began the active division. The nuclear DNA content of these cells was measured by microfluorometry. It was found that foe DNA content declined rather than increased. When the cell accoml)lished several divisions,the DNA content was steady.