To use starch agar plates to show digestive activity during germination:
• Broad bean seeds were disinfected (no contamination) to ensure they were sterile. They were then soaked in water (48Hrs) to activate the digestive enzymes and soften the testa (seed coat).
• Half of the seeds were then boiled (to kill them) and the other half were left untreated.
• The seeds were then cut in half lengthways and placed cut side face down on the starch agar plates (to expose the digestive enzymes to the substrate (nutrient -starch agar)).
• Seeds were then placed in an incubator (25°C) for 48hrs.
• The plates were then removed and tested with iodine for the presence of starch.
Result: The plates that had seeds which had been boiled went completely black/blue (presence of starch) proving no digestion had taken place. There were clear areas under the normal seeds showing that digestion had taken place (absence of starch).