Effect of(12)C (+5) ion beam irradiation on cell viability and plant regeneration in callus, protoplasts and cell suspensions ofLavateva thuringiaca.

The biological effects of irradiation with(12)C(+5) ion beam on plant cells have been analyzed. Protoplasts and cell suspensions ofLavatera thuringiaca, and a somatic hybrid callus (Hibiscus rosa-sinensis +Lavatera thuringiaca), were irradiated with doses from 0.05 to 50 Gy, and the effects on cell growth, cell division, cell viability and embryogenesis rates were analyzed. Irradiation with(12)C(+5) ion beam at relatively very low doses (5.0 Gy) significantly inhibited cell division, yet the survival rate and regeneration capability of the cells through somatic embryogenesis were conserved in more than 70 and 50 %, respectively. These results indicate that cell division is the most sensitive parameter to irradiation, accounting for the inhibition of colony formation and callus growth. The potential use of the(12)C(+5) ion beam in asymmetric protoplast fusion experiments is discussed.