Regeneration of Rice Plants from Suspension Cultures

Suspension culture of single cells and plant regeneration are of great importance to establish the new crop improvement system through cellular and chromosomal manipulation as well as clonal propagation. Mutant cell lines or variants have been obtained through cell selection (Wakasa and Widholm 1987). On the other hand, in general it is difficult to recover plants from suspension cultures. Cell suspension cultures of rice have been examined from the physiological and cytological view points (Maeda 1969, 1973; Ohira et al. 1973; Igaue et al. 1980). Plant regeneration from suspension cultures of rice has been reported by Ye (1984) and Abe and Futsuhara (1986). We also reported that plantlets regenerated at high rates from rice root callus via somatic embryogenesis in some indica cultivars (Abe and Futsuhara 1986). Plant regeneration via somatic embryogenesis from suspension cultures of cereals is preferable to organogenesis. Recently, plant regeneration from rice protoplast isolated from suspension cultures which originated from seeds and anthers has also been demonstrated (Fujimura et al. 1985; Toriyama et al. 1986; Kyozuka et al. 1987), in which plant regeneration was attained at a high rate through somatic embryogenesis (Kyozuka et al. 1987).