Symbiosis is a type of relationship between at least two organisms that co-exist in a particular environment. There is a symbiotic relationship between bacteria and plants. Nitrogen-fixing bacteria help plant growth and this project will help students know how it happens.
What you need:
• 6 clay pots that look alike
• Potting soil or Sphagnum moss
• Paper and drawing pens
• Pea seeds
• Magnifying lens
• Sterilizes inoculating loop
• Culture of Rhizobium leguminosarum
How to do it:
1. Get your pots. Label three of them “bacteria” and another three “control”.
2. Put the same amount of potting soil or moss in each pot.
3. Plant three seeds in every pot.
4. Place the pots in an area where there is enough sun. Water them.
5. Five days after planting the pea seeds, get your inoculating loop and sterilize it. With the loop, incorporate the culture of Rhizobium leguminosarum into the three “bacteria” pots. (If you choose the powdered form of the bacteria, sprinkle about ½ teaspoon of it over the soil in the three pots.
6. Allow the pea seeds to grow untouched for at least 9 weeks. Be sure to measure the largest leaves, the growth of every plant, and the number of leaves of each plant. Make notes of new leaves that sprout. Take photographs regularly.
7. After nine full weeks, uproot your seedlings. Take your magnifying lens and study the roots.
8. Draw what you see.
In this experiment, you found out that nitrogen-fixing bacteria are vital in plant production and growth as a limiting element. It serves as a big component of chlorophyll, which is a pigment required for photosynthesis. This element is also present in other biomolecules such as nucleic acid and adenosine triphosphate (ATP). Plants get nitrogen naturally from the Earth’s atmosphere when there are storms. Nitrogen is also available as combined nitrogen for plants. It comes in the form of nitrate fertilizer, ammonia, manure, decaying matter, nitrogen fixation, and lightning.