What are coralloid roots??????
- There are two types of branch roots.
- They are 1) long-branching geotropic roots, 2) short-branching apogeotropic roots that is they grow upward toward the surface of the soil, instead of downward into its depths
- Cycads have a short branching apogeotrophic roots are called as coralloid roots. Because they resemble to coral with an irregular and beady appearance. They contain symbiotic cyanobacteria which fix nitrogen. This has unique characteristics which facilitate a close relationship between cycad and cyanobacteria. Cyanobacteria within the coralloid roots of Cycads are chemoheterotrophic and specifically adapted to life in symbiosis. All Cyanobacteria in symbiosis with Cycads have the ability to fix nitrogen.