ABSTRACT
The procedures of plant tissue culture have developed to such a level that any plant species can be regenerated in vitro through several methodologies. Plant tissue culture, which covers all types of aseptic plant culture should be used in a restricted sense and it is possible to distinguish it into various types of cultures. The types include seed culture, embryo culture, organ culture, callus culture, cell culture, and protoplast culture. In plant tissue culture, more often we use an explant (an excised piece of differentiated tissue or organ) to initiate their growth in culture. The non-dividing, differentiated, quiescent cells of the explant when grown on a nutrient medium first undergo changes to achieve the meristematic state. The phenomenon of mature cells reverting to a meristematic state and forming undifferentiated callus tissue is termed as dedifferentiation. Organogenic differentiation is an outcome of the process of dedifferentiation followed by redifferentiation of cells.
