Study on protective enzyme activities of alfalfa leaves from satellite carrying seeds with different moisture contents

Seeds with different moisture contents (9%、11%、13%、15%、17%) of Medicago sativa cv. Zhongmu No.1 were boarded on the Shijian8 satellite. Using the age 3 of plants in SP1 as study materials, activities of leaf protective enzymes (SOD, CAT, POD) and MDA content were analyzed statistically. The results of the study showed that plant protective enzymes activities and MDA contents of alfalfa leaves from seeds with different moisture contents were different. The leaf protective enzyme activities with 13% and 15% seed moisture contents in control group were significant lower than that with 9% seed moisture content (P0.05); the leaf MDA content with 13% seed moisture content was significant higher than that with 9% seed moisture content (P0.05). In satellite carrying group, mutagenic efficiency of the seed with high moisture content could be increased. The leaf protective enzyme (SOD, CAT and POD) activities of satellite carried seed with 13% and 15% moisture content were significant higher than those of the seeds with same level of moisture content and 9% moisture content in control group (P0.05). The leaf MDA content of satellite carried seeds with 13% moisture content was dropped comparing with those of the seeds with same level of moisture content and 9% moisture content in control group significantly (P0.05). The results showed that the space mutagenesis enhanced the activities of SOD, CAT and POD, and reduced the accumulation of MDA and level of lipid oxidation, but the antioxidant capacity of plants was enhanced.