不同土壤肥力下旱后复水对冬小麦光合特性及水分利用效率的影响

为给冬小麦节水高产栽培提供理论依据，采用盆栽试验，研究了不同土壤肥力下返青后干旱及拔节期复水对冬小麦光合特性和水分利用效率的影响。结果表明，同一土壤水分条件下，光合速率、蒸腾速率、气孔导度、胞间CO2浓度均随土壤肥力的降低而降低；同一土壤肥力下，光合速率、蒸腾速率、气孔导度、胞间CO2浓度均随干旱程度的增加而降低。干旱胁迫复水24 h后，光合速率、蒸腾速率、气孔导度、胞间CO2浓度均出现了补偿或超补偿效应，但中度干旱恢复度大于重度干旱。光合速率以HA处理（高肥力、最大田间持水量的85%）最高，单叶水分利用效率在干旱胁迫下和复水24 h后均以HB处理（高肥力、最大田间持水量的55%）最高。以上结果说明，冬小麦返青期中度干旱条件下，高肥力土壤有利于复水后光合系统恢复和单叶水分利用效率提高，而重度干旱下贫瘠土壤应减少基肥的施入量。

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.