Physiological Responses of Leucaena leucocephala Seedlings to Drought Stress

In order to test L. leucocephala's ability and uncover the physiological mechanism to adapt to draught, the paper investigated the physiological responses of L. leucocephala seedlings in leaf water content, chlorophyll content and photosynthetic capacity to drought stress. Results showed that the seedlings had a good ability to keep water as its LWC, and did not decrease significantly until 12d draught. The chlorophyll content increased significantly meanwhile the Chlorophyll (a/b) ratio decreased; The Pn, Tr and stomatal Gs of leaves significantly decreased, but the WUE increased; These results showed that L. leucocephala seedlings could maintain a reasonable physiological activity by keeping LWC, increasing chlorophyll content and reducing photosynthetic activity when subjected to drought stress. Therefore, it displays considerable tolerance to draught stress and could be selected as a suitable pioneer species for the ecological restoration of degraded ecosystem in Southwest China.