Effects of low energy (160 keV) X-ray on microbial inactivation, sprouting inhibition and genetic variation in potato

The effects of low energy X-ray irradiation on microbial inactivation, sprouting inhibition and genetic variation were surveyed. There was an inverse correlation between the exposure dose in range of 0 Gy–5000 Gy and the survival rate of microorganisms. The dose of 1000 Gy seemed to be suitable for inactivation of microorganisms because the respective survival rate is relatively low (0.59%). Dose rate of 13.87 Gy/min was the most appropriate to inactivate the microorganisms, with the survival rate of 0.37%. Applying the irradiation dose of 1000 Gy and dose rate of 13.87 Gy/min, there was a significant sprouting inhibition of irradiated potatoes compared to the control for six months storage. The effect of irradiation dose (100–1200 Gy) and dose rate (8.63–19.62 Gy/min) on genetic variation of the irradiated samples was assessed by DNA fingerprints induced from using three molecular techniques including Random Amplified Polymorphic DNA (RAPD), Start Codon Targeted Polymorphism (SCoT) and CAAT box – derived polymorphism (CBDP). At the irradiation dose of 1000 Gy and dose rate of 13.87 Gy/min, the level of genetic variation was relatively low (4.85%). Thus, this treatment is a suitable condition of irradiation for potato treatment with the purpose of preservation.