硒对低温胁迫下番茄幼苗叶片光合特性与叶绿素荧光参数的影响

The Effects of Se on the Photosynthesis Characteristic and ChlorophyⅡ Fluorescence Parameters of Tomato Seedlings Leaves under Low Temperature Stress

以加工番茄‘里格尔87-5’幼苗为试材,对其外施Na2SeO3溶液Se0.3、0.6、0.9、1.2mg/kgNa2SeO3,并进行昼(12±1)℃/夜(8±1)℃的低温胁迫处理。研究硒对低温胁迫下加工番茄幼苗叶片光合作用及叶绿素荧光参数的影响。结果表明:随着低温胁迫时间的延长,番茄幼苗叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和胞间CO2浓度(Ci)减小;叶片初始荧光(Fo)、非光化学荧光猝灭系数(qN)上升;最大荧光(Fm)、PSⅡ最大光化学效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)、光化学猝灭系数(qP)表现下降。不同浓度的硒溶液可以缓解低温胁迫对番茄幼苗光合作用和叶绿素荧光参数的影响,并且以Se0.9mg/kgNa2SeO3的作用效果最好。

A tomato variety Ligeer87-5＇ was used to study the effect of photosynthesis characteristic and chlorophy Ⅱ fluorescence parameters of its seedlings leaves by infliction Se 0.3, 0.6, 0.9, 1.2 mg/kg Na2Se03 liquor under low temperature stress, day time （12±1）℃ and night time （8±1）℃. The results showed that, with the extended of time of the low temperature stress, the photosynthetic rate（Pn）, stomatal conductance（Gs）, intercellular C02 concentration（C1）, and several fluorescence parameters including maximum fluorescence（Fro）, photochemical maximum efficiency of PS II （Fv/Fm）, potential photochemical effieiency（Fv/Fo）, photochemical quenching coefficient（q_P）, were decreased. At the same time, minimal fluorescenee（Fo）, nonphotochemieal quenching coefficient（qN） were increased. Otherwise, the different Se levels treatment could relieve effects of low temperature stress on photosynthesis characteristic and chlorophy Ⅱ fluorescence parameters in tomato seedlings and the optimal treatment concentration of Se was Se 0.9 mg/kg Na2SeO3.