Biological effects of space mutagenic factors on different genotypic japonica rice

The results showed that space flight led to the decline in germination percentage, seedling survival rate and seed setting rate of Japonica rice when compared with the check, and had facilitating or inhibiting effects on seedling growth. Physiological damage after space flight was much smaller than that treated with γ ray irradiation. Some cultivars showed the segregations of grain color in the M1 generation. More stronger segregation of characters such as plant height and heading date appeared in the M2 generation. Mutation frequency (MF) and mutagenic efficiency (ME) varied with different genotype. After treatment with the same cultivar by space flight and γ ray, MF and ME varied with different mutation characters. However, many mutants with desirable agronomic characters were obtained in M2 generation and were probably to be bred as a new cultivar by selection