农药胁迫对生菜叶片叶绿素荧光图像参数的影响

摘要

对生菜(Lactuca sativa)分别均匀喷洒浓度为70、140、280μg/L的杀虫剂氰戊菊酯，以清水为对照，以意大利全年耐抽薹生菜为试材，结果表明，随着农药浓度的增加，光系统Ⅱ的最大光化学效率、实际光化学效率、光化学淬灭系数和相对电子传递速率均下降，非光化学淬灭系数、非调节性能量耗散的量子产额和调节性能量耗散的量子产额上升，综合影响造成光系统Ⅱ的中心活性区域缩小、光合速率下降。另外生菜叶片自身的光化合保护机制能在一定程度上减轻农药的胁迫作用。与对照相比，光系统Ⅱ的实际光化学效率受农药影响最大，喷洒浓度为280μg/L的杀虫剂会对生菜光合作用过程产生持续性的、不可逆转的影响。%The Italy lettuce samples were sprayed evenly with water and pesticide fenvalerate with concentrations of 70,140,280 μg/L to study the adverse effect of pesticide on chlorophyll fluorescence parameters of lettuce leaves.With the increase of concentration of pesticide sprayed on the lettuce leaves,the biggest photosynthetic efficiency of photosystem Ⅱ(Fv/Fm),actual photosynthetic efficiency YI,photochemical quenching coefficient (qP) and relative electron transport rate declined and showed a clear decrease,meanwhile the non-photochemical quenching coefficient (qN),regulatory quantum yield of energy dissipation (Y NPQ) and non-regulatory quantum yield of energy dissipation (Y NO) increased significantly. Because of these disturbances,centre activity area of photosystem Ⅱ and actual photochemical efficiency was reduced. Light protection mechanisms of the lettuce leaves alleviated the impact of pesticides to a certain extent.Compared with control group,the actual photosynthetic efficiency of photosystem Ⅱ was one of the most exposed to effects from pesticide.The influence of 280μg/L pesticides on lettuce photosynthesis was continuous and irreversible.