Let us make an in-depth study of the importance of organogenesis in different fields of plant science.

The regeneration of plant from cell and cal­lus culture via Organogenesis is a wide field of plant science. So, the importance and applica­tions of organogenesis are vast and varied.

With the discovery of cellular totipotency and the de­velopment of methods for regeneration of plant from in vitro cell culture, a large number of plant species including economically important crop plants, medicinal plants, horticulturally impor­tant plants, timber yielding plants etc. have been successfully regenerated from callus culture via organogenesis and the reports of regenera­tion of other plants are still increasing day by day.

The production of large numbers of haploids from microspores and the possibility of rais­ing triploids from endosperm cell culture are the dramatic instances of the potential role of orga­nogenesis in genetics and plant breeding.

Im­provement of crop plants through manipulation at the cellular level such as the vegetative hy­bridization by the fusion of isolated protoplasts of distantly related plants, the transfer of foreign genetic material in protoplasts etc. is possible only if somatic cells are able to give rise to whole plant; a plant breeder is interested in obtaining modified plants than modified cells.

Regenera­tion of whole plants through organogenesis is of special interest in mutagenic studies. Chemical mutagens and ionizing radiation can be used in bringing about genetic diversity in plants and by means of cell culture and the regeneration of whole plants from somatically mutant cell types, the new strains of mutant plants are obtained through organogenesis.

This method is very use­ful in mutation breeding of both sexually and vegetatively reproducing plants. A new source of genetic variability is also available in plants regenerated from cell culture. This soma clonal variation is a useful source of variability only if plants can be efficiently regenerated from the cell culture via organogenesis.

Variation in chromosome number of cells i.e. aneuploid, polyploid has also been observed in callus culture. By means of organogenesis a wide range of aneuploid plants have been recov­ered from tissue culture of numerous plants. Re­duction in chromosome number has been noted in plants regenerated from callus culture of triploid rye-grass hybrids.

A wide range of ane­uploid having addition and reduction in chro­mosome number are also achieved in sugarcane. Each of these chromosomal variations is associ­ated with phenotypic variation, including agri­culturally useful characters such as disease re­sistance.

Therefore, variability in chromosome number, if not associated with depression of yield, is particularly valuable in vegetatively pro­pagated medicinal plants and agricultural crops. Freeze preservation of cell culture of many plant species and the regeneration of plant from them after a desirable time period is another impor­tance of organogenesis for the conservation of endangered plant species.

In the application of in vitro methods for the improvement of the ge­netically potential plants for the production of primary and secondary compounds, there gen­eration of plants from cell and tissue cultures attains special significance. Therefore, the suc­cess of all available in vitro cellular and molecu­lar techniques for the improvement of plants de­pends upon the ability to regenerate plants from single cells and callus culture via organogenesis.