渗透调节对冷敏感大豆[Glycine max(L.)Merr.]种子膜类脂组成和脂肪酸含量的影响

选用冷敏感的大豆[Gzycine max（L.）Merr．]品种“中黄22”为试材，运用薄层层析法和气相色谱法研究了渗控增强大豆种子活力过程中膜类脂的组成及变化规律，揭示生物膜类脂在抗吸胀冷害中的作用。结果表明，用33％（W／V）的PEG6000处理种子，随着渗控时间的延长，种子的发芽指数、活力指数和根干重都逐渐增加，在渗控72h时，大豆种子中不饱和磷脂如PC、PE的比例增加，各极性脂的脂肪酸组成也发生了变化，PC、PE和PI中饱和脂肪酸16：0的含量显著下降，而不饱和脂肪酸18：2明显上升，使它们的不饱和指数大大提高，并与渗控时间呈正相关。由以上结果可证明，经PEG渗控处理后，提高了冷敏感大豆膜的流动性，为防止吸胀冷害，保持膜系统的完整性和生物膜正常的代谢提供了前提条件。

Effects of Osmoconditioning on Membrane Lipid Components and Fatty Acid Content of Cold-sensitive Soybean Seeds

Cold-sensitive soybean (Glycisne maxZhonghuang No.22) seeds were used to investi-gate the effects of osmoconditioning for invigora-tion of seeds chilling tolerance and the changes inmembrane lipid by thin layer chromatography andgas chromatography to disclose the role of mem-brane lipid played in imbibitional chilling resis-tance capacity. Results are as follows: being treatedwith 33% PEG6000, seeds germination indexvigor index and root dry weight presented the trendof upward as the osmocondition time prolonged(Fig.1). In 72 h, the percentage of unsaturated phos-pholipid (e.g. PC and PE) in soybean seed increased(Fig.2), composition of lipid fatty acid changed:the saturated fatty acid 16:0 content in PC, PE, PIsignificantly decreased, while unsaturated fatty acid18:2 increased greatly (Tables 1, 2), which led toincrease index of unsaturation fatty acid of lipid(Table 3). These changes were positively correctedwith osmoconditioning time. After treated withPEG, membrane fluidity increased to provide pre-condition for preventing imbibitional chilling,keeping the integrity of membrane system and nor-mal metabolism.