A tube that grows from a pollen grain on the stigma of a flower down through the style into the ovary.
When a pollen grain lands on the stigma of a flower, it is stimulated to produce a pollen tube. This is an outgrowth of the inner membrane of the pollen grain, and burrows its way through the tissue of the stigma, the style and then the ovary. Eventually the tip of the pollen tube finds its way through the small hole in the integuments surrounding the ovule and penetrates it. As the tube grows, the contents of the pollen grain - essentially genetic material - passes down the tube. When the tip of the tube enters the ovule, the genetic material flows into the ovule and fuses with the genetic material of the female gamete. This fertilisation results in an embryo plant. The pollen tube requires very specific conditions to germinate; this helps to make sure the pollen grain and the stigma are of the same species, and so no cross-species reproduction takes place.
slender tubular outgrown from a pollen grain that penetrates the ovule and releases male gametes
A tube which grows out from the pollen after germination and carries the male gametes down the style to the ovary
A slender thread-like growth, containing sperm cells, which penetrates the female tissue (stigma) of a flower until it eventually reaches the ovary; there the sperm cells unite with the ovule.
A slender structure produced from a pollen grain after pollination.
Structure produced by the tube nucleus in the pollen grain through which the sperm nucleus (or nuclei in angiosperms) proceed to travel through to reach the egg. PICTURE
The tube formed by a pollen grain when it grows down the style of a pistil. Volume 3, Number 4 Hibiscus International August-October 2003
In seed plants, the extension of the male gametophyte as it emerges from the pollen grain in search of the female gametophyte.
The pollen tube acts as a conduit to transport sperm cells from the pollen grain, which has landed on the stigma, to the ovules at the base of the pistil. The pollen tube germinates from the pollen grain and grows the entire length through the stigma, style and ovules to reach the eggs. In maize, this single cell can grow longer than 12 inches to traverse the length of the pistil.