Q. Application of auxin in a concentration far more than cytokinin then callus to undergo:
NTA AbhyasNTA Abhyas 2020
Solution:
A callus is an undifferentiated mass of cells that can be developed from any totipotent cell of the plant. This can be cultured in an artificial medium containing sugar and various essential minerals (Na, Ca, K, S, P, Mg, etc.) and single or combination of plant growth regulators (like IAA, GA, or BAP).
Caulogenesis is the formation of shoot from the callus, which occurs due to more concentration of BAP, Kinetin, or Zeatin in the medium. This can also be initiated if there is less concentration of IAA, NAA, or IBA in the medium.
Rhizogenesis is the formation of roots from the callus, which occurs due to more concentration of IAA, IBA, or NAA in the medium. This can also be triggered by the concentration of BAP, Zeatin, or Kinetin is kept less in the medium.
Morphogenesis is the formation of some deformed, or normal morphological features. There is a hormone called Morphactin, which helps in morphogenesis. All other plant growth regulators can also induce morphogenesis in a callus. This term overall describes root, stem, leaf, xylem differentiation as well.
When the auxin to cytokinin ratio is maintained, morphogenesis takes place. If auxin is more, rooting occurs, while if cytokinin is more, shoot formation occurs. They are represented as two triangles (as shown in the figure):
Caulogenesis is the formation of shoot from the callus, which occurs due to more concentration of BAP, Kinetin, or Zeatin in the medium. This can also be initiated if there is less concentration of IAA, NAA, or IBA in the medium.
Rhizogenesis is the formation of roots from the callus, which occurs due to more concentration of IAA, IBA, or NAA in the medium. This can also be triggered by the concentration of BAP, Zeatin, or Kinetin is kept less in the medium.
Morphogenesis is the formation of some deformed, or normal morphological features. There is a hormone called Morphactin, which helps in morphogenesis. All other plant growth regulators can also induce morphogenesis in a callus. This term overall describes root, stem, leaf, xylem differentiation as well.
When the auxin to cytokinin ratio is maintained, morphogenesis takes place. If auxin is more, rooting occurs, while if cytokinin is more, shoot formation occurs. They are represented as two triangles (as shown in the figure):