A hollow tube which develops from a pollen grain when deposited on the stigma of a flower. It penetrates the style and conveys the male gametes to the ovule.
- ‘For example, low temperatures near flowering affect ovule development and pollen tube growth.’
- ‘Guidance of the pollen tube down the style involves mechanical, chemical and physical cues that are not yet fully understood.’
- ‘In only one pollination did a pollen tube appear to enter the ovary, but not the ovule.’
- ‘The grain is empty because the body cell and prothallial nuclei have moved out along the pollen tube towards the archegonia.’
- ‘In pre-zygotic mechanisms, the pollen tube may grow as far as the ovule but not penetrate it, or penetration may be achieved without fertilization.’