紫外线(UV-C)辐射对早熟禾生理特性的影响

Effects of Enhanced UV-C Radiation on Photosynthetic Characteristics of Poa pratensis

采用室内盆栽试验方法研究了不同时间紫外线UV-C辐射后,CO2浓度增加、光合有效辐射变化对早熟禾(Poa pratensis)生理特性的影响。结果表明,UV-C辐射对早熟禾的净光合速率产生了明显的抑制作用,而且随辐射时间的延长,抑制作用增大。在1600μmol·m-2·s-1光合有效辐射条件下,早熟禾净光合速率较800μmol·m-2·s-1光合有效辐射的净光合速率降低。CO2浓度增加可使早熟禾净光合速率增加。Logistic模拟分析表明,在CO2浓度不断增加条件下,早熟禾的最大净光合速率随UV-C辐射时间的延长下降,而且在强光下其最大值具有降低的趋势。相关分析表明,UV-C辐射是导致早熟禾气孔下降的主要因素,与CO2浓度增高相关性较低。蒸腾速率的变化规律与气孔导度相同。

The physiological characteristics of Poa pratensis were studied under different CO2 concentrations and different net photosynthetic radiation after enhanced UV-C radiation in pot experiments. The net photosynthetic rate obviously decreased under UV-C radiation and the inhibition increased as the increasing of radiation time. The net photosynthetic rate under the active photosynthetic radiation of 1 600 μmol·m^-2·s^-1 was lower than that of 800 μmol·m^-2·s^-1 .The increasing of CO2 concentration could enhance the net photosynthetic rate after UV-C radiation. The simulating analysis by logistic equation showed that the maximal net photosynthetic rate decreased with the radiation time of UV-C when the CO2 concentration increased and the maximum of net photosynthetic rate decreased under high active photosynthetic radiation. UV-C radiation led to the decreasing of stomatic conductivity and correlation value was low between CO2 concentration and stomatic conductivity. Evaporation rate had the same tendency with stomatic conductivity.