After the embryo sac in fertilized by the pollen tube
, the ovule gradually turns into a seed, and the carpel becomes a fruit.
The pollen tube
enters the opening of the ovule, the micropyle, and reaches the interior of the ovule to undergo spenn release and fertilization (Endress, 1996).
Recently pollen physiology especially germination and viability has received considerable attention for its application in plant breeding, conservation, adaptation and understanding of physiological behavior of fertilizing pollen grains, there are several reports on pollen germination, viability and tube length from different taxa [33,22,42,2314], but a little research concentrates on pollen tube
morphology which is important also to complete fertilization successfully.
In Cretaceous flowers we've never before seen a fossil that shows the pollen tube
actually entering the stigma," said George Poinar, Jr.
Sex for a plant happens when male pollen lands on the female part of a flower, called the stigma, and then grows a pollen tube
down the style, which is attached to the stigma, to reach and fertilize an egg.
After a pollen grain lands on a receptive stigma of a pistil, a pollen tube
germinates from the hydrated pollen grain and delivers the immotile sperm cells over a long distance toward the ovule.
Beneath the stigma is a tubular style, into which a pollen tube
(growing out from a pollen grain) tunnels until it reaches the ovary and, finally, the ovule (egg) at the bottom of the style.
We are studying KCBP in the conifer pollen tube
system of Norway spruce as a potential calcium regulated link between microfilaments and microtubules.
Equally important are the steps that lead to that fusion, such as the sprouting and elongating of the pollen tube
The decision to use pollen grains resulted from the need in a previous semester to demonstrate pollen tube
growth in an upper-level botany course.
Three adjacent stigmatic chambers provide growing pollen tubes
access to one ovary; the remaining two stigmatic chambers provide pollen tube
access to the second ovary (Sage et al.
S-RNases that inhibit pollen tube
growth in incompatible crosses