Effect of drought stress on photosynthesis and some other physiological characteristics in flag leaf during grain filling of wheat

There are three water treatments in this study, that is control (CK), moderate drought stress (MS), severe drought stress (SS), during anthesis and filling stage of wheat. Some physiological characteristics of flag leaf was measured. The results showed that the contents of soluble protein in flag leaf under moderate drought stress was similar to that under control during 0-28 days post-anthesis, and lower under severe drought stress. After 8 days of anthesis, the contents of soluble sugar in flag leaf of two drought treatments is higher than that of control, and respectively higher 2. 8% and 3. 7% on 28 days of anthesis. The contents of proline was significantly increased in flag leaf under two drought treatments before 16 days of anthesis, and then decreased, The contents of chlorophyll, rate of photosynthesis and transpiration, stomatal conductance, Single leaf WUE in flag leaf under moderate drought stress is similar to that under control during grain filling stage, but obviously reduced under severe drought stress except for leaf WUE. With drought increasing the water potential in flag leaf declined, and in severe drought stress was 1. 3MPa lower than that of control on 23 days of anthesis.