Cupressus) the pollen grains contain just two nuclei: a GENERATIVE NUCLEUS and a VEGETATIVE NUCLEUS (tube nucleus).
Cupressus) the pollen grains contain just two nuclei: a GENERATIVE NUCLEUS and a VEGETATIVE NUCLEUS (tube nucleus).
当花粉粒形成后，花粉粒壁上分布有萌发孔，花粉管从萌发孔处向外突起形成管状结构，生殖核转入管中。