Drug encyclopedia

Pollination is the event of pollen landing on a stigmatic surface e. G the pistil, and fertilization is the union of the staminate chromosomes from the pollen with the pistillate chromosomes from the ovule. Pollination starts with dehiscence ( release of pollen ) from staminate flowers. Millions of pollen grains float thru the air on light breezes, and many land on the stigmatic surfaces of close by pistillate plants. If the pistil is ripe, the pollen grain will germinate and send out a long pollen tube much as a seed pushes out a root.

The tube contains a haploid ( in ) generative nucleus and grows downward toward the ovule at the base of the pistils. When the pollen tube reaches the ovule, the staminate haploid nucleus fuses with the pistillate haploid nucleus and the diploid condition is revived. Germination of the pollen grain happens fifteen to twenty mins after contact with the stigmatic surface ( pistil ) ; fertilization may take as much as a couple of days in cooler temperatures. Straight after fertilization, the pistils wither away as the ovule and surrounding calyx begin to swell. If the plant is correctly watered, seed will form and sexual reproduction is complete. It is critical that no part of the cycle be interrupted or workable seed won’t form. If the pollen is the subject of extremes of temperature, humidity, or moisture, it’ll fail to sprout, the pollen tube will die before fertilization, or the embryo will not be able to develop into a developed seed. Systems for successful pollination have been designed with all of these standards under consideration.