Abstract:Asparagus seeds were sent on board retrievable satellites and they were flown in space for 8 days. Experiments were conducted in fields and laboratory after the seeds returned to the earth. Comparative studies were made on the growth and development patterns of plants growing from space flown seeds and controls kept on the earth. Changes in physiological and biochemical characteristic of the seedlings were also studied. The results obtained are summarized as follows: (1) Space flight markedly raised the germination rate of seeds as compared with the controls kept on the earth. After 5 days of imbibition, 40% of the space flown seeds germinated while the germination rate for ground controls was only 22.5%. After 6 days of imbibition the germination rate of space flown seeds was 65 % and that of ground controls 40%. After 10 days of imbibition, the rates rose to 87. 5% and 72. 5% respectively. The seedlings from space flown seeds grew in fields much faster than ground controls. The yield of tender stems of the former was 34% higher than the latter. (2) An assay on respiration showed that the respiratory intensity of space seedlings was 61% higher than that of ground controls. This indicated that the vigor of seeds enhanced under space conditions, accelerating the germination of seeds and growth of seelings. (3) The proline content of space seedlings was 33% higher than that of the ground controls. At the same time, the permeability of the plasma membrane of the space seedlings was markedly lower than that of the ground controls. The content of aspartic acid in plants grown from space seeds was slightly higher than in ground controls while the content of asparagus was markedly lower.