Enhancing growth rate of lettuce by mutating lettuce seeds with nuclear irradiation

To improve growth rate of hydroponics lettuce with CO2 aeration, lettuce seeds were mutated by nuclear irradiation (γ rays from 137Cs) and domesticated with high concentration of CO2. When lettuce seeds were mutated with 30 Gy dosage, wet weight of lettuce increased by 22.3% (to 52.24 g) on the 30th day and grana volume in the chloroplasts of leaf cells increased by 244%. After the mutant (irradiated by 50 Gy dosage) was domesticated with elevated CO2 concentration, wet weight of lettuce increased by 74.6% (to 48.7 g) on the 24th day under 3 vol% CO2, compared with wet weight of lettuce under air condition. Results showed that mutagenesis by nuclear irradiation made it possible to improve CO2 fixation rate in lettuce in a gene-modified way. Keywords: Biomass productivity, CO2 domestication, Grana volume, Lettuce productivity