Principles and botanical basis of  Plant Tissue Culture

          In principle any plant can be propagated using  two main types:

* Sexually; by seeds; or/and

* Asexually (vegetatively, also called cloning); by cuttings, division, layering, grafting , etc.....

In some ornamental woody plants and under certain conditions, both types may be very difficult or even impossible.

 Sexual Propagation is excluded in the following cases:

* No seeds are formed

* Very few seeds are formed

* Seeds quickly loose their germination viability

 Asexual (Vegetative) propagation is very important in plant breeding programs, since parent lines need to be maintained and propagate vegetatively for seed production. However, these classical methods may be unsatisfactory in the following cases:

* With plants whose natural rate of increase is too slow

* With new cultivars that is too difficult or can not readily or

          economically be clonally propagated by these classical methods.

* When it is too expensive to commercially use these methods.

           The field of plant biotechnology provides techniques for rapid propagation of ornamental plants. Many of ornamental plants and woody species are propagated using tissue culture techniques (also known as micropropagation). However, these methods may be difficult to apply to woody plants, particularly in the adult form and most of the reports were dealing with the juvenile form.

           The term micropropagation is used to refer to the application of plant tissue culture techniques to clone (propagate) species using small piece of the mother plant such as shoot tips, meristem tips, lateral buds, …etc. to be grown aseptically in a test tube or any other glassware container.