利用EPR技术快速预测不同含水量杜仲种子的玻璃化转变温度  

Quick Prediction of the Glass Transition Temperature for Eucommia ulmoides Seeds with EPR Technique

作　　者：于文文[1,2] 林坚[1] 孙红梅[1,2] 辛霞[1,2] 程立宝[1,2] 景新明[1] 

机构地区：[1]中国科学院植物研究所 [2]中国科学院研究生院,北京100039

出　　处：《中国农业科学》2007年第8期1654-1659,共6页Scientia Agricultura Sinica

基　　金：中国科学院知识创新方向性工程(KSCX2-SW-117)

摘　　要：【目的】本试验基于玻璃态理论,利用电子顺磁共振(Electron Paramagnetic Resonance,EPR)波谱技术快速预测杜仲种子的最适贮藏条件。【方法】以3-carboxy-proxyl(3-羧基-2,2,5,5-四甲基吡咯烷-1-氧)探针标记杜仲种胚,利用EPR技术扫描不同含水量种胚在不同温度下的EPR波谱,选用波谱参数2Azz的变化作为反映分子运动快慢的指标,以温度为横坐标,2Azz为纵坐标作图,得到温度-2Azz关系曲线,2Azz发生大幅度变化时所对应的温度就是玻璃化转变温度。【结果】含水量为4.4%、5.7%、8.6%、10.3%、11.6%杜仲种胚的玻璃化转变温度分别约为44℃、25℃、4℃、-31℃、-43℃。试验所得出的含水量-玻璃化转变温度曲线可以用来预测种子的最适贮藏条件。【结论】利用EPR技术测定杜仲种胚的玻璃化转变温度,通过含水量-玻璃化转变温度曲线可以较快捷准确地预测其种子最适贮藏条件。[Objective] It is crucial for germplasm conservation to research the optimum storage condition for seeds. In this experiment, the glass theory and EPR technique were used to predict the optimum storage condition for Eucommia ulmoides seeds quickly. [Method] The EPR spectra of the spin labelled axes of Eucommia ulmoides with different moisture contents during the change of temperature were examined 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, the temperature-2Azz curve was obtained. 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 oblained 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, can predict the optimal storage condition for seeds quickly and reliably.

关 键 词：杜仲种胚 最适贮藏条件 EPR 玻璃化转变温度 

分 类 号：S567.19[农业科学—中草药栽培]