Plant tissue culture is a technology widely used in fast propagation of cash plants. It requires strict aseptic techniques to ensure no contamination occurs. The principle of tissue culture is cell totipotent, in another word, every plant cell has the potential to develop into a whole plant. However practically actively growing tissue such stem tips are more easily to manipulate. You don’t want to pick an old leaf tissue to carry out tissue culture. But that is still possible by using plant hormones to bring the tissue back to early stage cells like callus.
plant tissue culture has also useful to remove harmful diseases. The virus eradication procedure involves a combination of chemical, physic methods, allowing the most actively dividing tissues on the very top of stem able to grow faster than the spreading speed of the pathogen. Following by large scale plant tissue culture, a few pathogen free cells would redefine the whole population.