Equipment
Safety
Results
- Sucrose solution 2moldm-3
- Mineral salt culture medium
- Microscope
- Plants in flower
- Five Petri Dishes
- Filter paper
- Distilled water
- Measuring cylinders
- Stop clock
- Clean cavity slides
- Mounting needles
- Make up the planned solutions ith different concentrations of sucrose. For example solutions 0, 0.2, 0.4, 0.8 and 1.6moldm^-3.
- Collect one Petri dish per sucrose concentration and label the dishes. Place filter paper in each dish, moisten the paper with water and replace the lids. The Petri dish will act as a humid chamber in which the pollen slides will be placed to prevent them from drying out. The slides will be used without a coverslip to prevent anoxic conditions developing that may prevent pollen tube growth.
- Collect one microscope slide per sucrose concentration and label the slides. Place a few drops of the sucrose plus mineral salt medium in the central cavity of each slide.
- Gently rub the point of a mounted needle over the anthers so that pollen falls on to the medium on each slide. Dislodge any pollen stuck to the needle by tapping the needle against a pencil or forceps. Repeat for each sucrose concentration, using the same flower.
- Note the time at which the pollen was added to the medium and place the slides in the Petri dishes. Remove only when observing with the microscope.
- Record pollen growth every hour using a microscope at 100x magnification. Calculate the percentage of cells with tube growth. To prevent the samples drying out or overheating, make your observations quickly before turning off the microscope lamp and returning the slide to the Petri dish.
- Record your results in a suitable format such as a table and graph.
Safety
- Take care with glass slides and mounted needles to prevent breakages and stick injuries.
- Wash your hands after handling flowers of plant stems.
- If you have a pollen allergy ensure that you take appropriate precuations such as wearing gloves
Results