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

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.