Phenotypic variation of sweet sorghum after carbon ion beam irradiation

The survival rate, DNA mutation rate, phenotype variation, sequence analysis of Hd1 and Hd3a were investigated after the dry seeds of sweet sorghum were irradiated by carbon ions. The results indicate that there was a marked stimulatory effect under low doses in terms of survival rate. The carbon ion irradiation also induced phenotypic variation and the mutation frequency differed as the dose increased. The maximum DNA mutation rate was 18.95%, which occurred at 200 Gy, whereas the mutation rate decreased to 17.87% at 240 Gy. The sequence analysis indicated that there was no difference between KF and KC for the Hd1 gene, but 2bp insertions were clearly observed in KF compared to KC in the case of the Hd3a gene. In conclusion, there was a significant phenotypic variation after carbon ion beam irradiation in sweet sorghum.