Effect of Drought and Rewatering on Photosynthetic Characteristics and Leaf Water Use Efficiency of Winter Wheat under Different Fertility Conditions

Pot experiments were conducted to study the effects of drought and rewatering on photosynthetic characteristics and leaf water use efficiency of winter wheat under different fertility conditions.The results showed that photosynthesis rate,transpiration rate,stomatal conductance and intracellular CO2 content decreased with the reduction of fertilizer levels under the same water condition,and decreased with the serious of drought levels under the same fertility condition.Photosynthesis rate,transpiration rate,stomatal conductance and intracellular CO2 content all presented compensatory or ultra compensatory effect after 24 hours of rewatering,and the restoration degree was greater under moderate drought stress than under serious drought stress.Photosynthesis rate of high fertility and 85% soil water treatment was the highest among all the treatments,while leaf water use efficiency exhibited the highest in high fertility and 55% soil water treatment.The results suggested that properly increasing fertilizer amount was conducive to the recovery of photosynthetic system and increase of water use efficiency winter wheat,which were rewaterd after moderate drought stress at regreen stage.And the amount of the base fertilizer should be reduced under serious drought stress.