【摘要】 晴天条件下 ,田间姜叶片的光化学效率 (Fv/Fm)和表观量子效率 (AQY)上午随PFD升高而降低 ,12～ 14时后随PFD的降低而升高 ,中午前后丙二醛 (MDA)含量达到最高 ,而光合速率 (Pn)出现低谷 ,表明午间强光使光合作用发生光抑制 ,甚至光氧化。超氧物岐化酶 (SOD) 14时以前呈增加趋势 ,之后逐渐降低。苗期遮荫 60 % ,Fv/Fm与AQY明显提高 ,MDA含量降低 ,SOD活性减弱 ,Pn降低且日变化曲线变为“单峰型” ,表明苗期适当遮荫有利于提高光合效率和PSII光化学效率 ,减轻光抑制和光氧化。强光下喷施SOD抑制剂二乙基 -二硫代氨基甲酸酮盐 (DDTC) ,使Pn、AQY及Fv/Fm明显降低 ,光抑制加重 ,而遮荫条件下喷施同浓度DDTC则影响较小 ,表明SOD在强光下对姜叶片光合机构具有保护作用。更多还原

【Abstract】 On sunny day,the photochemical efficiency of PSII(Fv/Fm)and apparent quantum yield(AQY)of ginger leaves declined gradually in the morning,but raised progressly after 12:00.The MDA content in ginger leaves increased,but the photosynthetic rate(Pn)declined under mid-day high light stress.SOD activity in ginger leaves increased gradually before 14:00,then decreased.Shaded 60% in seedling stage,Fv/Fm and AQY of ginger leaves increased,but MDA content,SOD activity and Pn decreased.Pn,AQY and Fv/Fm of ginger leaves treated with DDTC decreased whether shading or not,but the effect of DDTC on shaded plants was less than that on unshaded plants.It is clear that mid-day high light stress caused photoinhibition and lipid peroxidation of ginger leaves.SOD and shading play an important role in protecting the photosynthetic apparantus of ginger leaves against high light stress.更多还原