The protoplast plating efficiency of this, and other economically-important cereals, is still low when compared to the generally more efficient proto- plast systems of their dicotyledonous counter- parts. Abdullah et al. (1986) reported that while initial division occurred in up to 57% of cells derived from cultured protoplasts isolated from several varieties of Japonica rice, only ca. 1% of such protoplasts underwent sustained mitotic divi- sion leading to visible cell colonies. The results obtained using rice protoplasts are dependant on a number of variables, primarily the source mate- rial and plant genotype. At present, embryogenic cell suspensions are the prime source material for the isolation of totipotent rice protoplasts. How- ever, as well as the choice of plant variety, source material and culture medium used, additional in- novative approaches are also required to elevate rice protoplast systems, in terms of their plating efficiency, to levels more comparable to those of dicotyledons.