Comparison of density of nuclear pores on vegetative and generative nuclei in pollen of Tradescantia

The freeze-etch technique has been used to expose surface views of vegetative and generative nuclear envelopes in both ungerminated and germinated pollen of Tradescantia paludosa. A comparison of the density and total numbers of nuclear pores on the two nuclei indicates that vegetative nuclei have at least twice as many pores as generative nuclei. These findings are compatible with the concept that the vegetative nucleus plays a more active role in pollen tube development than the generative nucleus.