Future prospects of mutation breeding with genetic engineering

The recent advance in plant tissue culture techniques, including the isolation of protoplasts, cell fusion, and the regeneration of plants from cultured cells enables the production of a wide variety of hybrid materials. The rate of natural mutation is raised by the long-term in vitro culture of de-differentiated cells: the mutagen given to cultured cells is more efficient than that given to seeds for inducing mutants: new hybrids between hitherto incompatible species can be produced by cell fusion; and foreign genetic material which is not normally taken up by intact plants can be taken up by protoplasts. The gene transfer between different organisms is now possible, and foreign genetic information can be expressed in incorporated host cells. At present, although this technique is applicable mostly in prokaryotic organisms, it may be applied to higher plants in the near future. The most important factor in this technique is the identification and isolation of a suitable vector. The stable incorporation, maintenance and multiplication of foreign DNA segments in plant cells are other factors to be considered for the accomplishment of genetic manipulation in higher plants. (Kaihara, S.)