Effects of drought stress and rewatering on seedling growth and physiological characteristics of Lysimachia davurica

The effect of 20 d drought stress and rewatering on seedling morphological and physiological characteristics of Lysimachia davurica were studied. The results showed that growth and development of L. davurica were gradually inhibited as drought stress extended. The growth of above ground part of seedling was depressed first when drought stress lasted for less than 10 days and soil moisture content was higher than 14.52%. The leaf area and relative water content were reduced, while chlorophyll content, MDA content, soluble sugar, proline, POD and CAT activities of seedling were increased. The plant could quickly restored growth except the shoot tip when rewatering at this time. When drought stress lasted for 15 days, the seedling severely lost water and the upper part of the seedlings shriveled. 66.66% new sprout grew after rewatering. L. davurica would be dying and could not be revived after rewatering if drought stress lasted for 20 days. Therefore, L. davurica should be rewatered timely to rescue seedling when the drought stress was more than 10 days and the soil moisture content was less than 14.52%.