盐胁迫对梭梭幼苗渗透调节物质含量的影响

采用浓度为0,50,100,200,350,500 mmol/L的 NaCl和 Na2 SO4两种单盐溶液对梭梭幼苗进行处理,取样周期为10 d,取样3次,测定梭梭幼苗中渗透调节物质的含量,研究盐胁迫对梭梭幼苗体内渗透调节物质含量的影响.结果表明：两种盐胁迫下,梭梭幼苗同化枝中可溶性糖含量随盐浓度的增加和胁迫时间的延长而增大,但增幅较小,说明梭梭幼苗可溶性糖的积累对盐分的响应并不敏感.两种盐胁迫下梭梭幼苗同化枝中淀粉含量变化趋势相似,淀粉含量随盐浓度的增加和胁迫时间的延长而显著下降（P ＜0．05）,说明梭梭幼苗接收到盐胁迫信号后通过降解淀粉生成可溶性糖来减轻盐伤害.两种盐胁迫下梭梭幼苗同化枝中可溶性蛋白的变化趋势相似,可溶性蛋白含量随盐浓度的增加和胁迫时间的延长而下降,说明盐胁迫下梭梭幼苗体内可溶性蛋白转变成氨基酸（包括脯氨酸）,以此来降低渗透势维持平衡.350 mmol/L和500 mmol/L NaCl处理下梭梭幼苗脯氨酸含量呈极显著增加（P ＜0．01）,以此来降低其渗透势,减小盐害程度.两种盐胁迫下,梭梭幼苗同化枝中脯氨酸含量随盐浓度的增加而增加,与 Na2 SO4处理相比,NaCl处理下梭梭幼苗中脯氨酸含量较高.

Effects of Salt Stress on the Osmotic Regulation Substances of Haloxylon ammodendron Seedlings

The two kinds of salt solution with NaCl and Na2 SO4 of 0,50,100,200,350,500 mmol/L were used to process Haloxylon ammodendron seedings,the sampling period for 10 days by 3 times was deG signed to determine the content of osmotic regulation substances and study the influence of saltstres on the content of Haloxylon ammodendron seedlings.The result showed that the content of soluble sugar of Haloxylon ammodendron seedlings increased with the increase of the concentration and stress time.The starch content significantly decreased with the increase of salt concentration and prolonging of stress time （P ＆lt;0.05）which showed that Haloxylon ammodendron seedlings reduced injure from salt by degrading sluble strach,under the stress of the two kinds of salt,the change of soluble protein in Haloxylon ammoG dendron seedlings were similar to each other,the content of soluble protein reduced with increase of salt concentration and prolonging of stress time,which indicated that under the salt stress,the soluble protein in Haloxylon ammodendron seedlings changed into amino acid including proline,by which the osmotic poG tential was reduced and the balance was maintained.The proline content in Haloxylon ammodendron seedG lings was significantly increased （P ＆lt;0.05）under the treatment of 350 mmol/L and 500 mmol/L NaCl,by which the osmotic potential reduced and the salt inj ury was reduced,under the stress of the two kinds of salt,theprolinecontentinHaloxylonammodendronseedlingsincreasedwiththeincreaseofsaltconcentration,compared with Na2 SO4 treatment,the proline in Haloxylon ammodendron seedlings was higher.