渗透调节增强大豆种子活力

Osmoconditioning Improves Soybean Seeds Vigor

选用对吸胀冷害敏感的大豆 [Glycinemax(L .)Merr.]品种‘黑河 2 3’为试材 ,系统研究了渗控增强种子活力的机理。结果表明 ,与对照相比 ,渗控 1 2h显著提高种子抗吸胀冷害的能力 ,并且随着渗控时间的延长逐渐增强 ,表现在种子渗漏物减少 ,渗漏物中K+ /Na+ 比降低 ,冷浸对活力指数的负效应减小。水苏糖、蔗糖的含量在 1 2h达最大值 ,以后呈缓慢下降趋势 ,而葡萄糖、果糖含量在渗控后期开始上升。过氧化氢酶 (CAT)、过氧化物酶 (POD)、超氧化物歧化酶(SOD)、谷胱甘肽还原酶 (GR)等抗氧化酶的活性在整个渗控过程中都有不同程度的增强 ,丙二醛 (MDA)含量减少。表明渗控可提供一个合适的渗透压 ,使种子在适度的渗透压下启动萌发过程。研究还揭示2 2℃渗控效果优于 4℃。

Soybean(Glycine max Heihe No.23)seeds which were sensitive to imbibitional chilling injury were used to systematically investigate the effects of osmoconditioning for invigoration of seeds chilling resistance and the mechanism of such effects. The results indicated that the osmoconditioning pretreatment can significantly improve resistance of seeds to imbibitional chilling in 12 h,which can be strengthened as the osmoconditioning time was prolonged, as shown as the diminished of electrolyte leakage and K +∕Na + ratio of seeds,the diminished of the negative effect of cold imbibition on seed vigor of seeds after being osmoconditioned(Figs.6,8,3). The stachyose and sucrose contents reached their maxima after osmoconditioning treatment for about 12 h, then decreased, however the glucose and floccose contents increased in the late stage of osmoconditioning(Fig.7). Activities of catalase (CAT), peroxidase (POD), superoxide dismutase(SOD) and glutahione reductase (GR) increased to different extented during the whole osmoconditioning process(Table 1). But the malondialdehyde(MDA) content reduced (Table 1). These results demonstrated that the osmoconditioning to keep an appropriate osmolarity so that the cell membranes of the seeds could undergo repair under moderate osmotic pressure before going into full imbibition. The results also revealed the osmoconditioning effect was better in 22℃ than in 4℃(Figs.4,5).