Alteration of resistance to black Sigatoka (Mycosphaerella fijiensis Morelet) in banana by in vitro irradiation using carbon ion-beam

Carbon-ion beam is a new irradiation source for inducing mutations in plant breeding effectively. In order to apply this new technique in banana breeding program, we studied the critical doses for in vitro irradiation and the genetic variability for black Sigatoka in the regenerated plants. Carbon-ion beam was irradiated to in vitro plantlets of banana cultivars ‘Cavendish Enano’ and ‘Williams’ with the dose of 0, 0.5, 1, 2, 4, 8, 16, 32, 64 and 128 Gy. Biological effects on survival rate were recorded and 8 Gy was supposed to be the best dose. Survived plantlets were propagated in vitro to evaluate resistance to black Sigatoka. Six plants from ‘Williams’ population and two plants from ‘Cavendish Enano’ population were selected as candidates for resistant plants to black Sigatoka in the field, suggesting that carbon-ion beam could be useful for mutation breeding in banana.