Pollen grains contain the male gametes in sexually reproducing plants. A pollen tube grows from the stigma, through the style, and into the ovary where it enters an ovule. The sperm nuclei then pass through the pollen tube into the ovary where fertilization takes place. We cannot see the growth of the pollen tube because it takes place within the style. However, we can watch the growth of pollen tubes in vitro by germinating them in a liquid medium or on agar plates.
Pollen germination depends upon the presence of sucrose, calcium, and boron.
Abnormal or no germination will occur in their absence. Movement of the cytoplasm, cytoplasmic streaming, can also be observed in healthy pollen tubes. To investigate the germination of pollen tubes in vitro and to investigate the importance of calcium and boron in the growth medium. Equipment Growth chambers Microscope slides Agar plates Growth media Lilies with mature pollen Compound microscope Procedure 1. When the glass is cool, place it into the dish and add a thin layer of water to the bottom of the dish.