[A study on the induction of mutation of paddy rice under space conditions]

Rice seeds were carried into space by the recoverable satellite. After recovery the seeds were sowed on the earth so as to observe the character performance and genetic variation of their later generations. The preliminary results showed that the main characters of the SP1 generation didn't show significant difference from the control. Among the individual plants of the SP2 generation strong broad-spectrum segregation appeared in the 9 main agronomic characters. Mutation frequency is 4.66%. The individual plants of the SP3 generation were obviously correlated with the SP4 generation in the average character values of the 5 main characters. Stable plant strains were obtained in the SP4 generation. The SP5 and SP6 generations were put into control and polt tests. As a conclusion, it may be considered that certain variations of rice seeds induced by the space conditions are heritable to the offsprings, therefore, it can be used as a new method for mutagenic seed breeding.