Ultrastructural transformations of nuclei in differentiating Hyacirlthus orientalis L. pollen grain cells

Abstract

The ultrastructure of the pollen nuclei was studied during pollen maturation in Hyacinthus orientalis L., in which both pollen cells go through full interphase (G₁ S, G₂). The particular stages of interphase, however, do not proceed simultaneously in the vegetative and generative nuclei. The ultrastructural transformations of both pollen nuclei were analysed with reference to the dynamics of variations in the level of RNA and protein synthesis, investigated earlier. A distinction is drawn between the structural changes common for both nuclei, linked immanently with the interphase and the transformations connected with the differentiation of pollen cells.