Protoplasts capable of division and plant regeneration are now available for a large number of vegetable, oil and forage crops. However, routine hybrid production is not possible due to methodological limitations in selection and culture of hybrid cells. Recent improvement in techniques are the use of a double mutant as a universal hybridizer and the use of fluorescence activated cell sorter to recover hybrid cells. Interest is also centered on limited gene transfer by protoplast fusion. We propose a model of generating triploid plants by somatic cell fusion to transfer limited genomic information from an alien plant to a crop plant. Somatic hybridization has some novel features but, in practice and conception, it is an extension of the methods of sexual hybridization. By contrast, genetic transformation is a radically different approach to plant genetic manipulation. The success of this approach will depend upon how readily genotype can be related to phenotype in a tangible way so as to ascertain what biochemical and developmental activity is controlled or modulated by a DNA sequence
