【摘要】 用Cd浓度为0、25、50、100μmol·L-1 Hoagland营养液培养3个欧美杂交杨无性系XMH-4、MH-8、XMH-10扦插苗5个月后,处理植株的叶绿素含量、光合作用、PSⅡ原初光化学反应量子效率均显著降低。对5种与光系统密切相关的矿质元素的分析表明:镉处理显著增加Ca、Mg、Fe、Cu在功能叶的含量,极显著地降低Mn的含量。结合叶绿素荧光和元素分析结果,推测镉胁迫使PSⅡ反应中心氧化端出现电子传递障碍,镉胁迫下的黄化症不是由于Mg或Fe的缺乏引起的,而是镉胁迫导致Mn亏缺,抑制叶绿素合成造成的。更多还原

【Abstract】 The effects of cadmium(Cd) on photosynthesis and chlorophyll fluorescence parameters were studied in poplar plants. Experiments were carried out with poplar cutting plants of clone XMH-4(Populus deltoides×P. nigra), MH-8(P. trichocarpa × P. deltoides) and XMH-10(P. deltoides × P. nigra) treated with 0, 25, 50, 100 μmol·L~ -1 Cd-solution for 5 months under normal conditions in greenhouse. The result showed that cadmium significantly decreased chlorophyll,photosynthesis and quantum yield of PSⅡphotochemistry. The contents of calcium(Ca), iron(Fe), magnesium(Mg) and copper(Cu) all increased with the 25, 50 μmol·L~ -1 Cd-treatments, only manganese(Mn) showed a robust negative relation with Cd-concentration. It was suggested that some problems occurred to the electron transport chain at the oxidation side of PSⅡreaction centres(RCs), and the cadmium-induced etiolation were not caused by lack of iron or magnesium, but manganese. Therefore manganese may play an important role in cadmium stress to plant.更多还原