Studies On Effect Of Treatment With Ultradrying On Membrane Lipid Constitution And Fatty Acid Content In Seeds

Ultradry storage keeps germplasm genetic integrity and improves seed longevity and storability. It is has broad application foreground for plant germplasm conservation. In this research, starch rich seeds of maize (Zea mays), protein rich seeds of elms (Ulmns pumila) and oil rich seeds of safflower (Carthamus tinctohus) seeds were chosen for further investigating the mechanism of ultradry seed storability. The results showed that ultradry treatment improved the seeds storability significantly. The optimum moisture contents of various seeds were different. Electron paramagnetic resonance spectroscopy and differential scanning calorimeter were introduced to determine the intercellular biophysics characteristics of ultradry seeds. The optimum moisture contents of seeds indicated by the DSC and EPR were in agreement with the results of the aging experiments, which provided theoretical foundation for the prediction of the optimum moisture contents of ultradry seeds from the molecular mobility. Results are as follows: Polar lipid composition and content of elm seed are the most, maize lower, safflower least, this shows that membrane lipids in starch seeds play a better role than protein and oil seeds; Membrane lipid composition differ greatly between different seed types, fatty acid content changes remarkablely, all these indicate membrane lipid composition play a different role in keeping the integrity of membrane system and membrane normal metabolism process. Oil seeds are considered with special desiccation tolerance mechanism.