Growing the plant cells, tissues and organs on a artificial, synthetic medium under controlled conditions is called plant tissue culture. Plant tissue culture has become a major thrust area in plant biotechnology.
The basic concept of plant tissue culture is totipotency, differentiation, dedifferentiation and redifferentiation.
The inherent potential of any living plant cell to develop into entire organism is called totipotency. This is unique to plant cells.
The meristematic tissue is differentiated into simple or complex tissues.
Reversion of mature tissue into meristematic state leading to the formation of callus is called dedifferentiation.
The ability of the callus to develop into shoot or root or embryoid.
The beginning of plant tissue culture was made as early as 1898, when a German Botanist G. Haberlandt successfully cultured individual plant cells, isolated from different tissues. But only during 1934 to 1939, a foundation of plant tissue culture was laid down by three scientists (Gauthret, White and Nobecourt) due to discovery of plant growth regulators such as auxins and vitamins.
During next twenty years (1940 to 1960) a variety of growth regulator such as cytokinins were identified for their effect on cell division, growth and differentiation.
After 1960, in vitro culture of plant cells, tissues and organs was reasonably well developed. Research in this area was initiated in early 1960s by Prof. P. Maheshwari and Prof. S. Narayanaswamy at the Department of Botany, University of Delhi in India. Consequently, media and culture techniques for a variety of plant materials became known, which are now extensively utilised in all areas of plant improvement programmes.