Synopsis The development of plant biotechnology has been related to the discovery of the growth regulators and their progressive introduction in tissue culture. The micro propagation technique offers not only means for mass propagation but also plays an important role to conserve elite or rare plants that are threatened with extinction. Moreover, meristem tip culture offers the possibility of virus eradication. These technologies started about 20 to 25 years ago, especially for ornamental plants, and for a few other crops. Propagated clonally, it was very important to have a true to type propagation techniques.