Where is pollen formed

Essentially, the anther is where the pollen grains are produced! The image to the right is of a young Lily anther. Within each of the chambers you will see white dots. During this stage, the pollen sacs and the cells within them undergo some major changes. Through cell division, the microsporocytes change to form clusters or groups of four called quartets within each of the four different chambers.

You can see this process happening on the right side of the picture above to the left. The microspores within the chambers white dots within the chambers are almost ready to become pollen grains but first they must undergo 3 more changes which occur almost simultaneously!

Each microspore then undergoes nucleus division. The two nucleus that are developed are the generative nucleus and the vegetative nucleus which are involved in how the pollen grain achieves fertilization. When these events are completed, the microspores have become pollen grains! See the picture to the right for a close up of the final product! Close Menu Home. GAPP Map. Your Pollinator Garden.

In fact, the job of each individual pollen grain is to protect and transport male plant DNA, or genetic material, to the female part of a flower, called the stigma. Pollen evolved to allow fertilization to take place between plants that were not close to each other. By taking advantage of wind, animals brushing past and, of course, bees, pollen can travel quite a distance before it fertilizes a flower.

How pollen is made can vary a little from plant to plant, but all pollen is generally produced the same way. The formation of a pollen grain begins inside the male part of a flower called the anther, within specific tissue called sporogenic tissue.

Here, the developing pollen receives nutrition and a coat of cellulose, which is a very strong plant protein. First, large pollenmothercells are produced, which eventually break into individual pollen grains through cell division. At this point, the pollen grain gets its outer coat, called the exine, which is made from another tough plant protein. The exine protects the delicate genetic material inside the pollen grain from water loss, and damage caused by UV radiation and other environmental causes.

Microsporogenesis comprises the events which lead to the formation of the haploid unicellular microspores. During microsporogenesis the diploid sporogenous cells differentiate as microsporocytes pollen mother cells or meiocytes which divide by meiosis to form four haploid microspores. Each diploid meiocyte gives rise to a tetrad of four haploid microspores and microsporogenesis is complete with the formation of distinct single-celled haploid microspores.

Microgametogenesis comprises events which lead to the progressive development of the unicellular microspores into mature microgametophytes containing the gametes. This phase begins with the expansion of the microspore which is commonly associated with the formation of a single large vacuole. Vacuolation is accompanied by the displacement of the microspore nucleus to an eccentric position against the microspore wall. In this position the nucleus undergoes first pollen mitosis pollen mitosis I which results in the formation of two unequal cells, a large vegetative cell and a small generative cell each containing a haploid nucleus.

The generative cell subsequently detaches from the pollen grain wall and is engulfed by the vegetative cell forming a unique 'cell within a cell' structure.