Physiological Response of Thuarea involuta under Drought Stress

Abstract:

Tropical coral islands have adverse natural conditions, and a very fragile vegetation ecosystem. In order to investigate the suitability of Thuarea involuta in arid environment of tropical coral islands, the physiological indexes of stress resistance of leaves were studied. The results showed that there was no significant difference in malondialdehyde (MDA) content of leaves among drought degrees at early stress stage. The MDA content rapidly increased at first and then decreased quickly under severe drought stress, which had little change under other drought treatments. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased with the increment of drought degree. Along the treatment time, SOD activity increased, POD activity was basically stable, and CAT activity decreased first and then increased. The soluble protein (SP) content under light drought stress was lower than that under control, which increased with increment of drought stress. The change in proline (Pro) content increased first and then decreased with the treatment time, but there was no significant difference among stress treatments at 18th day. Therefore, Thuare involuta had strong drought resistance ability and could be used for artificial plant community construction, vegetation restoration and improving environmental conditions of Nansha Islands.

Key words:Thuarea involute;Tropical coral island;Drought stress;Physiological response