[Response of wheat seedlings with different drought resistance to water deficiency and NaCl stresses].

The growth, photosynthesis, transpiration and antioxidative defence system of the seedlings of drought-tolerant wheat strain 8139 and drought-sensitive strain Ganmai No. 8 at 20% PEG 6000 and 1.2% NaCl stresses were compared. The results showed that strain 8139 had a strong drought resistance, but a weak salt resistance. The root growth of both wheat strains was inhibited significantly under salt stress, but stimulated slightly under drought stress. The net photosynthetic rate and water use efficiency of strain 8139 were significantly different from those of Ganmai No. 8 at every stage under both drought and salt stresses, and its transpiration rate was significantly different from that of Ganmai No. 8 only at 7th and 14th day after being stressed. The MDA content in strain 8139 after being stressed for 7 days was much lower than that in Ganmai No. 8 under drought stress, but there was no significant difference between the two strains under NaCl stress. Correspondingly, there was no significant difference in the fructan content and SOD and APX activities between strain 8139 and Ganmai No. 8, but a significant difference in GSH content was found under salt stress. Under drought stress, the contents of fructan and GSH and the activities of SOD and APX in strain 8139 were much higher than those in Ganmai No. 8 at different stage, and strain 8139 exhibited a strong antioxidative defence ability.