H_2O_2胁迫下菱角叶片的叶绿素荧光特性研究

Research on Chlorophyll Fluorescence Characteristics of Trapa Bicornis Leaves Under the Stress of H_2O_2

采用叶绿素荧光动力学技术,研究了H2O2胁迫对菱角叶片光合作用的影响.通过对48 h内菱角叶片最大光化学量子产量(F v/F m)、表观光合电子传递速率(ETR)、光合有效辐射强度(PAR)以及光化学淬灭系数(qP)和非光化学淬灭系数(NPQ)等参数的研究,结果表明,H2O2的胁迫抑制了菱角的光合作用,并且抑制的程度与H2O2的浓度及胁迫时间有关.随着H2O2浓度的增加,F v/F m总体呈下降趋势,F m、qP下降,F0上升,表明植物光系统Ⅱ反应中心被破坏,且浓度越高,破坏作用越明显.经高浓度H2O2(≥6 mg/L)处理的菱角叶片24 h内即出现死亡.低浓度H2O2(≤4 mg/L)处理的叶片则在48 h后出现死亡.部分数据异常变化则与H2O2在水体中的分解特性有关.

Using the technology of chlorophyll fluorescence kinetics, the paper studies the negative effect of H202 on the photosynthesis of trapa bicornis leaves. According to the measurements and analyses of the maximum photochemical quantum yield （Fv/Fm ）, the apparent photosynthetic electron transfer rate （ETR）, the photosynthetic active radiation intensity （ PAR）, the quenching photochemical coefficient （qP） and the non-quenching photochemical coefficient （ NPQ ） of trapa bicornis leaves under the action of H202 with different concentrations for 48 h,the results indicates that H202 can in- fluence the photosynthesis of trapa bicornis leaves, and that the degree of inhibition is related to the concentration of H2 02 and the contact time between them. With the increase in the concentration of H202, Fv/Fm overall shows a descending trend, Fm, qP drops while F0 rises, which indicate that the reaction center of light systemII in the plant has been destroyed, and that the higher the concentration is, the more serious it will be. The trapa bicornis leaves treated by n202 with high concentration（ ≥6 mg/L）appear dead within 24 h while those treated by H2 02 with low concentration （ ≤4 mg/L）appear dead within 48 h. The abnormal changes of some data are related to the decomposition properties of H202 in the water. Key words： H2 02 , trapa bicornis leaves, Chlorophyll fluorescence characteristic parameters, photosynthesis