Plants produce a number of exudates below the soil, some are for defense and others to encourage a diversity of organisms around their roots. A number of these organisms help to produce the nutrients the plants need via the n and c-cycles.
The tips of the roots produce the most sugars so you tend to see a higher and more diverse community of organisms. These bacterial communities fluctuate along the length of the root as each area provides a different niche.
Specific learning outcomes
- Understanding of ecological niches in plants below ground
- Understanding of symbiotic relationships
Equipment for a group of 5
- Soft bristle brush
- Petri dish with nutrient agar
- Marker pen
- Baking paper
Estimated time 50 minutes.
- Petri dishes, in not bought pre-made 30 mins
- Root material from various sites
Introduction 2 minutes, can look at images of some of the organisms associated with root communities.
Extract a number of plant roots, 10 minutes.
Prepare roots, 5 minutes.
Apply root to agar, 5 minutes.
Label and place in a dark, warm location.
Total timing 15-20 minutes.
Cultivation will be ~5-7 days.
Background learning needs
- Understanding of symbiotic relationship types.
- Extract a number of plant roots, cleaning off the soil gently so as not to loose the tips and delicate filaments
- Use the brush, sterilized by holding it over steam of the kettle, to brush off the remaining soil
- Cut a circle of baking paper and again hold this over the steam to clean it
- Place the root on to the agar and use the baking paper to press all the roots on to the agar
- Label and place in a dark, warm location.