There are two ways you can collect a pollen sample. Either way you do it, you probably need to know something about the anatomy of a flower. A flower is how an angiosperm (flowering plant) reproduces. The female part (stigma) gets pollinated by the male part (pollen), fertilization takes place, seeds are produced, and the seeds (hopefully) leave home and become full-grown respectable plants within the community. For an idea of how all this is set up see the diagram below:
|To collect the pollen, which is located on the anther, you need to collect an anther or dust a slide with pollen from the anther. Each of these procedures has an advantage: dusting the slide with pollen avoids damaging the plant and still gives you the pollen. Also, for flowers that don’t have particularly large anthers, this may be the only practical method. The anther method, on the other hand, gives you a better chance of getting the most pollen from your species. In any insect-pollinated species, there is the probability that there will be contamination with pollen from other species of plants.|
STEP 2…pollen tube set up
With your pollen sample back in the classroom, set up a moisture chamber by putting a little water and a glass "v-tube" in a plastic petri dish. Put a couple drops of 10% sucrose on a microscope slide. Transfer a small amount of the pollen to the sucrose solution…do NOT put a cover slip over your sample. Note the time you put the pollen on the slide. Put this slide on top of the "v-tube" and place the cover on the petri dish. Check the slide every 10 minutes and note any changes.
STEP 3…make slide for high power observation
While you are waiting for your pollen to form tubules, put a couple drops of water onto a second microscope slide. Take a little of your pollen sample and make a normal wet mount. Starting out at low power, view your sample then increase to high power as needed.
STEP 4…draw or photograph
Draw the pollen grains taking note of the shape, size, and details of the grains. Alternately, you may use the camera to photograph a particularly good pollen grain. You will still need to calculate the dimensions of the pollen grains. Make sure to label the drawing/photo with species (SEE Pollen Record Sheet).
STEP 5…list physical characteristics
These are needed to accompany the drawing/photo. View the pollen grain from the polar and equatorial perspectives.
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