Abstract:

To study the physiological changes of Symphytum officinale leaves under PEG simulating drought stress, different concentrations of PEG (0%, 5%, 10%, 15% 20%, 25%) were set up. The soluble sugar content, soluble protein content, free proline content, peroxidase activity and superoxide dismutase activity were measured. The results showed that with the increase of PEG concentrations (0%~25%), the soluble sugar content, the soluble protein content, POD activity and SOD activity increased first and then decreased. When the PEG concentration increased to 10%, POD activity and SOD activity reached the highest value, 270.3 U/(g·min) and 1167.7 U/g, respectively; the soluble sugar content and the soluble protein content was up to the maximum, 1.9 μg/g, 236.2 μg/g, respectively. The free proline content decreased first and then increased with the increase of PEG concentrations. When the concentration was 10%, the proline content reached the lowest value of 20.3 μg/g. It indicates that Symphytum officinale has a certain drought resistance, and it could alleviate the damage suffered through own adjustment ability in mild drought environment.

Key words: Symphytum officinale, PEG, Drought Stress, Physiological Characteristics, Drought Resistance