After the pollen grain germinates on the surface of the stigma, the vegetative nucleus migrates to the tip of the pollen tube.It is thought to regulate the growth and development of the pollen tube.

• 花粉粒在柱头表面发育后，其内的营养核向花粉管顶部移动，因此认为营养核具有调节生长和花粉管发育的作用。