Mutagenic effects of carbon ion beam irradiations on dry Lotus japonicus seeds

Abstract Carbon ion beam irradiation is a powerful method for creating mutants and has been used in crop breeding more and more. To investigate the effects of carbon ion beams on Lotus japonicus , dry seeds were irradiated by 80 MeV/u carbon ion beam at dosages of 0, 100, 200, 300, 400, 500 and 600 Gy. The germination rate, survival rate and root length of M 1 populations were explored and the dose of 400 Gy was selected as the median lethal dose (LD 50 ) for a large-scale mutant screening. Among 2472 M 2 plants, 127 morphological mutants including leaf, stem, flower and fruit phenotypic variation were found, and the mutation frequency was approximately 5.14%. Inter simple sequence repeat (ISSR) assays were utilized to investigate the DNA polymorphism between seven mutants and eight plants without phenotypic variation from M 2 populations. No remarkable differences were detected between these two groups, and the total polymorphic rate was 0.567%.