Abstract: In order to understand wind damage to corn seedlings and their physiological response mechanism,an experiment with two periods of wind blowing time (10 and 20 minutes) and six wind speeds〔0 (CK),6,9,12,15 and 18 m·s^-1〕was conducted in the Herqin Sand Land in west Inner Mongolia in spring 2013. The results showed that,under the 10-minute wind blowing,the MDA content was slightly increased and the membrane permeability tended to decrease with the increase of wind speed,but the differences of MDA and membrane permeability between the most treatments and the CK were not significant; SOD,POD and CAT activities changed in a fluctuation way,of which the SOD and POD activities were significantly higher and the CAT activity was lower under the wind speeds of 15 m·s^-1 and 18 m·s^-1 than those under the CK; soluble sugar and proline contents tended to increase,but their differences were not significant under the most treatments compared with those under the CK. Under the 20-minute wind blowing,the change of MDA contents under these treatments was not significant,but membrane permeability was significantly increased with the increase of wind speed. Moreover,SOD,POD and CAT activities and soluble sugar content were all increased considerably and the proline content tended to decreased. The results suggested that the damage of 10-minute wind blowing to the cell membrane of corn seedlings was not significant,and their membrane protective system did not play an effective action except for SOD and POD under the wind speed treatments of 15 m·s^-1 and 18 m·s^-1. The damage of 20-minute wind blowing to the membrane permeability was significant,and the damage degree was increased with the increase of wind speed. In the process,SOD,POD,CAT and soluble sugar played a protective role to alleviate the injury of membrane.

Key words: corn seedling, wind, membrane permeability, protective enzyme, osmotic regulation