Abstract: Abstract:【Objective】It is crucial for germplasm conservation to research the optimum storage condition for seeds. In this experiment, we used the glass theory and EPR technique to predict the optimum storage condition for Eucommia ulmoides seeds quickly.【Method】we examined the EPR spectra of the spin labelled axes of Eucommia ulmoides with different moisture contents during the change of temperature, with 3-carboxy-proxyl as a spin label. Using 2Azz as a measure of molecular mobility, taking temperature as X-scale, 2Azz as Y-scale, we get the temperature-2Azz curve. The temperature correlated to rapid change of 2Azz is the glass transition temperature.【Result】The glass transition temperature of axes with moisture content of 4.4%, 5.7%, 8.6%, 10.3%, 11.6% are 44℃, 25℃, 4℃, 31℃, -43℃respectively. The moisture content-glass transition temperature curve we had got can be used to predict the optimum storage condition for seeds.【Conclusion】Therefore, using EPR technique to determine the glass transition temperature of seeds, based on the temperature-2Azz curve, we can predict the optimal storage condition for seeds quickly and reliably.

Key words: Axes of Eucommia ulmoides, the optimum storage condition, EPR, glass transition, glass transition temperature