Effects of Altitudes on Physiological Indicators of Davidia Involucrata Leaves

To explore the physiological adaptation mechanisms of Davidia involucrate to altitudes, studies were made of the relationship between pigment, anthocyanin, malondialdehyde, proline, superoxide dismutase, and UV-absorbing compounds contents of Davidia involucrata leaf blades and altitudes. The research results showed that chlorophyll a and b, carotenoids, MDA content would decrease with the increase of an altitude, the maximum value of chlorophyll a/b ratio occurred at an altitude of 1 650 m, while the maximum contents of MDA occurred at an altitude of 1 590 m; anthocyanins, UV-absorbing compounds and Pro contents would reduce after first increasing with increasing altitude. The maximum contents of anthocyanins and Pro occurred at an altitude of 1 650 m, while the maximum content of UV-absorbing compounds occurred at an altitude of 1 590 m; leaf superoxide dismutase (SOD) activity would gradually increase with altitude increasing. In general, when Davidia involucrate got stress from adverse environment at high altitudes, it could protect itself by internal regulation in a certain altitude range.