混合盐碱胁迫对燕麦种子萌发及幼苗生理生化特性的影响

Effects of complex saline-alkaline stress on seeds germination and physiological and biochemical parameters of oats seedlings

为了探讨燕麦种子和幼苗的耐盐碱能力及在盐碱胁迫下的变化规律,采用纸上发芽法和砂培法,研究了混合盐碱胁迫对燕麦种子萌发及幼苗生理生化特性的影响。结果表明：随着盐碱胁迫浓度的增强,燕麦种子的发芽率、发芽指数、活力指数和幼苗生长与对照相比都呈下降趋势;而燕麦叶片中细胞膜透性增强和丙二醛含量增加,其中白燕1号较白燕7号增加幅度大,表明白燕1号比白燕7号对盐碱胁迫更敏感,受盐碱危害程度较重;同时燕麦叶片内游离脯氨酸和可溶性糖累积,且随着盐碱胁迫浓度的增强呈增大趋势,其中白燕7号增加幅度大,表明白燕7号可能主要通过积累脯氨酸和可溶性糖来进行渗透调节缓解逆境毒害作用,其中白燕1号在盐碱胁迫浓度100-200 mmol/L时,游离脯氨酸和可溶性糖含量下降,但其机理还有待于进一步研究。综合分析表明两个品种耐盐碱能力为：白燕7号〉白燕1号。

The effects of complex saline-alkaline stress on seeds germination and the physiological and biochemical parameters of oats seedlings were studied in detail. The result showed that the germination rate, germination index, vigor index of seeds and seedling growth were both declined; membrane permeability and content of MDA increased as complex saline-alkali concentration was increased, and the increasing of membrane permeability and MDA content of Avena nuda L. was greater than that of Avena Sativa L., which indicated that Avena nuda L. was more sensitive to salt than Avena Sativa L., and the degree of harm by the saline-alkaline is greater than Avena Sativa L. too; as while the accumulation of free proline and soluble sugar increased, and Avena Sativa L. was increased significantly. The result showed that the osmotic regulation in Arena Sativa L. is mainly by means of synthesizing or accumulating organic solute, and when saline-alkali stress concentration exceeded 100 - 200 mmol/L, the free proline content and soluble sugar content declined instead, although the mechanism of this effect is not clear. By analyzing comprehensively these physiological indexes, the result indicated that the order of the alkali - saline tolerance of seeds of 2 varieties was Baiyan 7 〉 Baiyan 1.