Girdling Experiment
Malpighi carried out the Girdling experiment in 1672, Stephen Hales in 1727, and Hartig in 1837. In woody stems, it entails the removal of all tissue save the vascular cambium (bark, cortex, and phloem) aside from the xylem.
- To determine the tissue that transports food, the girdling experiment is used.
- In this experiment, girdling, a process that removes a ring of bark (phloem) from the wood, is used.
- Water and nutrients reach the leaves due to the intact woody xylem portion.
- The removal of the phloem component prevents the photosynthate from being transferred to other areas below the girdle once it has been prepared.
- So it can be seen that photosynthate has accumulated slightly above the girdle region.
- The girdling experiment demonstrates that the tissue responsible for moving food is called phloem and that this movement is always in the direction of the root.
Phloem Transport
In plants, transportation is an important process. From roots to the tips of their leaves, plants carry the water and nutrients which are required to survive. The water and minerals are transported in plants by:
- Phloem
- Xylem
Xylem and phloem tissues are present all over the plants. These conducting tissues grow from the roots of trees and ascend through the trunks. Like spider webs, they eventually branch off into the branches and spread even more into every leaf.