干旱胁迫对蒙古黄芪种子萌发及生长生理的影响

Effects of Drought Stress on Germination and Growth Physiology of Mongolian Astragalus

目的:以PEG-6000溶液模拟干旱胁迫条件,探讨蒙古黄芪种子的萌发和幼苗生长对干旱胁迫的响应,为蒙古黄芪抗旱栽培提供技术依据。方法:采用滤纸做发芽床,清水为对照,用浓度分别为10%、20%、30%的PEG-6000溶液处理蒙古黄芪种子,测定黄芪种子的萌发率、幼苗生长量及叶片脯氨酸、丙二醛、可溶性糖、可溶性蛋白和叶绿素含量等抗旱生理指标。结果:10%PEG-6000浸种48 h显著提高了黄芪种子的发芽率,20%PEG-6000浸种48 h显著促进黄芪幼苗的生长。丙二醛、脯氨酸含量均随着PEG-6000浓度的升高而增加;丙二醛含量随着浸种时间的延长而增加,脯氨酸含量与浸种时间无显著相关性。根系活力、可溶性糖、可溶性蛋白含量、叶绿素a、b、a+b含量以及a/b值随着浸种时间的延长显著增加,而随着PEG浓度的升高除叶绿素b含量呈持续下降趋势外,其他各项指标均呈现先升高后降低的趋势。结论:中低浓度的PEG溶液处理蒙古黄芪种子有利于种子萌发和幼苗生长,而浓度过高则会出现抑制作用。可以选择20%PEG-6000浸种48 h处理黄芪种子,提高蒙古黄芪幼苗抗旱性。

Objective： This paper used PEG-6000 solution simulated drought stress conditions,explore the response of Mongolian Astragalus seed germination and seedling growth to drought,and provide a technical basis for seedlings of Mongolia Astragalus drought resistant cultivation research. Medthods： We used filter paper for germination bed,clean water for ck,and 10%,20%,30% PEG-6000 treated the seeds. Observe the seed germination and seedling growth even the seedling leaf proline,MDA,soluble sugar,soluble protein and chlorophyll content,to explore the seed germination characteristics and seedling drought resistance. Results：10% PEG-6000 soaked for 48 h can significantly improve the germination rate,20% PEG-6000 soaked for 48 h can significantly improve the seedling growth. MDA and proline content were increased with the increase of PEG-6000 concentration; MDA content were increased with the extension of seed soaking time,there was no significant correlation between seed soaking time with proline content. The root activity,soluble sugar,soluble protein content,chlorophyll a,b,a ＋ b content and a/b values were increased significantly with the extension of seed soaking time; in addition to the chlorophyll b content showed a trend of falling,their content were increased with the increase of PEG-6000 concentration presents a trend of increased before they were reduced.Conclusion： In brief,low concentrations of PEG-6000 is beneficial to seeds germination and seedling growth,but the high concentration can inhibit them. So 20% PEG-6000 soaking 48 h can be choosed using for increasing seedlings drought-resistance.