Effects of ultra-dry treatment and long-term storage on viability and vigor of corn and watermelon seeds.
超干水分长期贮藏对玉米、西瓜种子生活力和活力的影响

Corn ( Zea mays L.) seeds were subjected to ultradrying treatment before storage using two approaches, silica gel drying and heat drying at a comparating higher temperature, and then that stored for seven years under room temperature and airtight conditions. Results of seed germination and SOD activities measurement showed that viability and vigor of corn seeds which had their moisture content lowered to 4.05% by gel drying were highest, while those with a moisture content higher than 7.49% were nonviable. Corn seeds heat dried at higher temperature generally had lower viability and vigor. Germination percentage of such seeds was suddenly reduced to zero when moisture content till below 5.79% and hence were not suitable for ultradry storage. In this case, watermelon ( Citrullus lanatus (Thunb.) Matsum.et Nakai) seeds were only dried with Silica gel before storage in this experiment and then stored under the same conditions as corn seeds. Watermelon seeds that had the highest viability and vigor were those that had a moisture content of 3.73% and their germination percentage reached 71.5%. Both seed viability and vigor were significantly reduced when moisture content was either lower or higher than 3.73%. It is suggested that desiccation by silica gel drying is beneficial to long term storage of corn and watermelon seeds within certain length of period, but overdrying treatment is favorably applied to corn and watermelon seeds.