免揭地膜不同施氮量对烟叶叶绿素荧光参数的影响

研究了大田烤烟全生育期免揭地膜不同施氮量对烟叶光合作用和叶绿素荧光参数的影响,结果表明:随着施氮量的增加,烟叶光合速率、气孔导度和蒸腾速率都随之增大。虽然免揭地膜可以减少高降雨量对肥料流失的影响,但也给烤烟生长造成了一定的胁迫,施氮量越高,PSⅡ最大光化学效率Fv/Fm和Fv/Fo值越大,叶片吸收光能的光化学猝灭参数qP下降,可变荧光的非光化学猝灭参数qNP上升,表观光合电子传递速率(ETR)和PSⅡ实际光化学效率ΦPSⅡ值均降低。

Effects of Different Nitrogen Application Rates on Chlorophyll Fluorescence Parameters of Tobacco Leaves under Condition of Not Uncovering Plastic Film

Under the condition of not uncovering the plastic film in the whole growth and developmental period of flue-cured tobacco in field,the effects of different nitrogen application rates on the photosynthesis and chlorophyll fluorescence parameters of tobacco leaves were studied.The results showed that the photosynthetic rate,stomatal conductance and transpiration rate of tobacco leaves increased with the increase of nitrogen application rate.Not uncovering the plastic film could reduce fertilizer loss caused by high rainfall,but the chlorophyll fluorescence parameters indicated the growth of flue-cured tobacco was stressed by not uncovering the plastic film.When the application rate of nitrogen fertilizer increased,the PSⅡ maximum photochemical efficiency Fv/Fm and Fv/Fo values increased,the photochemical quenching coefficient qP relevant to the absorbability of leaf to the light energy decreased,the variable fluorescence non-photochemical quenching coefficient qNP increased,and the apparent photosynthetic electron transport rate ETR and PSⅡ actual photochemical efficiency ΦPSⅡ both decreased.