Tag: common modes of vegetative propagation

• Cellular totipotency is the ability of a single cell to produce all cell types and to organize them into an entire organism when cultured in a suitable culture medium at an appropriate temperature and aeration conditions. For example, Spores and zygote are examples of the totipotent cell.
  
• The concept of totipotency was established by a German Botanist, Professor Gottlieb Haberlandt in 1902 in the plant body. He stated that every living cell of the plant body able to regenerate the whole plant body because it is derived from the fertilized egg and contain hereditary information.
• Hence concept of cellular totipotency was established by Haberlandt.
• So, the correct answer is 'Haberlandt'.

Tissue culture is a biological technique which involves the development of the plant by the totipotent cells under the controlled condition on a nutrient culture medium of the known composition. The totipotent cells are taken from the active part of the plant like root, stem leaf, pollen etc. The plant part which is used for the culture is known as explant. 

Callus is unorganized actively dividing mass of cells maintained in culture. It has meristematic cell which has ample amount of cytoplasm to trigger cell division. It is an undifferentiated mass of cell which differentiates when treated with the growth hormones to promote cell division, differentiation and morphogenesis. It heals the injury in the cell as callus has meristematic cell which replaces the worn out and damaged cell by rapid cell division and it can also replace damage tissue developed in the region of wound.

Totipotency is the ability of the plant to generate new cell by cell division. A cell from leaf is made to grow into complete plant under culture conditions. The cell of the leaf used for the culture is taken from the tip of the leaf and it has ample amount of meristematic cell. The meristematic cell of the leaf is grown on a cultured media it develops into a undifferentiated mass of callus. The cells of callus have active nucleus and cytoplasm so they are totipotent. The totipotent cells of callus differentiate on treating with growth hormone. Callus when treated with auxin it promotes rooting and when it is treated with cytokinin it stimulates cell maturation, differentiation and finally, promotes the development of stem. 

F.C. Steward is associated with tissue culture and played an important role in developing the techniques. Caplin and Steward were the first one to use coconut water as a plant growth regulator in the nutrient media. Later on, it was considered as a substitute for cytokinin. He was also involved in the somatic embryogenesis in carrot cell suspension cultures and production of complete plants. He also laid the foundation of micropropagation technique.