渗透胁迫对皱果苋叶片渗透调节物质的影响

Effect of Osmotic Stress on Osmotic Adjustment Solute in Leaves of Amaranthus viridis L.

目的:研究渗透胁迫下皱果苋的渗透调节物质变化,探讨皱果苋的耐旱机理。方法:分别用浓度为5%、10%和20%PEG6000进行渗透胁迫,处理皱果苋幼苗0、1、3、5和7d,取叶片测定各项生理指标。结果:随着渗透胁迫时间的延长,皱果苋幼苗叶片中相对含水量(RWC)逐步下降;而脯氨酸和可溶性糖含量上升;在5d,5%、10%、20%PEG胁迫下的叶片脯氨酸含量分别是对照的3.73、6.27、9.77倍;而叶中可溶性糖含量分别是对照的2.87、3.68、5.21倍。胁迫3d,20%PEG处理的材料出现萎焉现象,胁迫5d,10%PEG处理的材料开始萎焉;在5%和10%PEG胁迫下,可溶性蛋白含量升高,但在20%PEG胁迫下,可溶性蛋白含量先升后降。结论:在适度的渗透胁迫下,皱果苋叶片中的渗透调节物质使其具有较强的渗透能力,形成皱果苋耐旱性的内在基础。

Objective：The purpose was to research change of osmotic adjustment solute of Amararahus viridis L under water stress and to discuss drought resistance mechanism. Method： The young plants of Amaranthus viridis L were treated by PEG6000 osmotic stress with concentrantions of 5 %, 10 % and 20 % for 0,1,3,5,7 days, and then leaves were taken out to be measured. Result： Along with time of osmotic stress, relative water content （RWC） descended gradually, proline and soluble sugar contents increased. Proline contents in 5%, 10% and 20% PEG were 3.73, 6.27 and 9.77 times of CK at the 5th day. While soluble sugar contents were 2.87,3.68 and 5.21 times of CK. In 3d, the leaves began to wither under osmotic stress with 20%, while osmotic stress with 10% began in 5d. Soluble protein content increased in 5% and 10%, but in20% first increased then decreased. Conclusion： Under moderate osmotic stress, Amaranthus viridis L had stronger osmotic adaptability, so these materials were inherent basis of superior drought tolerance of Amaranthus viridis L.