【摘要】 以苎麻为材料,采用盆栽培养,测定不同浓度镉胁迫下苎麻叶片中叶绿素含量、光合荧光参数及其荧光成像的变化,以及苎麻的镉耐受性及其光合荧光特性的关系。结果表明,短时间镉胁迫下,苎麻叶片的叶绿素a(Chla)、叶绿素b(Chlb)、总叶绿素含量(Chlt)、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)等指标与对照相比均呈上升趋势,而胞间CO2浓度(Ci)与稳态下的非光化学淬灭(NPQlss)呈下降趋势,且Pn、Gs、Tr与PSII最大量子产率(QYmax)均在Cd2+浓度为60 mg·L-1胁迫下出现最大值;长时间镉胁迫下,苎麻叶片的Chla、Chlb、Chlt、Pn、Gs、Tr等指标与对照相比则均呈下降趋势,而Ci呈上升趋势,除240 mg·L-1 Cd2+胁迫后的苎麻叶QYmax与NPQlss值分别高出对照的2.5%和75.9%外,其余不同镉浓度处理后的苎麻叶QYmax或NPQlss值均低于对照。更多还原

【Abstract】 On the basis of pot experiment methods, we selected ramie(Boehmeria nivea) as the materials, and measured all contents of chlorophyll, photosynthetic fl uorescence parameters and fl uorescence imaging in order to study the relationships among the tolerance to cadmium contamination of B. nivea and its photosynthetic fl uorescence characteristics under different concentrations of cadmium stress. Under different concentrations of cadmium stress in the short time of 21 days, the results showed that the values of the most parameters of B. nivea leaves increased more than those of the control group without any heavy metal stress, and the main parameters which included chlorophyll a, chlorophyll b, the total chlorophyll, and the net photosynthetic rate(Pn), stomatal conductance(Gs), transpiration rate(Tr) and etc., while the values of other parameters included the intercellular CO2 concentration(Ci) and the non-photochemical quenching under stable state(NPQlss) decreased less than those of the control group, and the values of the parameters included the net photosynthetic rate(Pn), transpiration rate(Tr), stomatal conductance(Gs) and the maximum quantum yield(QYmax) presented the highest under 60 mg·L-1 cadmium stress. With the increasing of stress time, under different concentrations of cadmium stress in the long time of 49 days, the values of chlorophyll a, chlorophyll b, total chlorophyll contents, Pn, Gs, Tr of B. nivea leaves decreased than those of the control group, while the values of Ci increased. And the change trend showed that the values of QYmax and NPQlss were lower than those of the control group under different concentrations of cadmium stress except the 240 mg·L-1 cadmium, and which values were higher than those of the control group 2.5%, 75.9%.更多还原