中文摘要：

采用盆栽试验,研究了不同氮肥用量[0、200、300和400 mg/kg CO（NH2）2]对Cd胁迫（50 mg/kg）下结缕草光合及叶绿素荧光特性的影响。结果表明：不同浓度的氮肥均能使Cd胁迫下结缕草叶片叶绿素含量、净光合速率（Pn）、气孔导度（Gs）、胞间二氧化碳浓度（Ci）、蒸腾速率（Tr）、光化学猝灭系数（q P）、叶片PSⅡ最大光量子产量（Fv/Fm）及表观光电子传递效率（ETR）有所提高,而非光化学猝灭系数（NPQ）有所降低,说明氮肥对Cd污染具有一定的缓释作用。从结缕草叶片叶绿素（叶绿素a、叶绿素b、叶绿素a＋b）含量、气孔导度、胞间二氧化碳浓度、叶片PSⅡ最大光量子产量及表观光电子传递效率指标来看,以氮肥浓度300 mg/kg缓解作用最大,200 mg/kg次之,400 mg/kg最弱;相对于叶片净光合速率、蒸腾速率、水分利用率（WUE）、非光化学猝灭系数来说,以氮肥浓度300 mg/kg缓解作用最为明显,400 mg/kg次之,200 mg/kg最弱;不同施肥浓度及镉胁迫对结缕草叶片光化学猝灭系数基本无影响（P〉0.05）。通过本研究得出：施用氮肥对Cd胁迫下结缕草具有一定的缓解作用,当氮肥浓度为300 mg/kg时缓解效果最为显著。

英文摘要：

The method of pot culture was used to investigate the proper application rate of the nitrogen fertilizer during the period of under cadmium stress （50 mg/kg） plant growth. The study was carried out to examine the effects of different dosages nitrogen fertilizer [ 0, 200, 300 and 400 mg/kg CO （ NH2 ） 2 ] on photosynthesis and fluorescence characteristics of Zoysia japonica under cadmium stress. The results showed that different dosages nitrogen fertilizer enhanced chlorophyll contents, net photosynthetic rate, stomata] conduction, intercellular CO2 concentration, transpiration rate, photochemical quenching, maximum photo quantum yield, and the electron transfer rate and decreased non-photochemical quenching （NPQ） under Cd stress, which demonstated that N fertilizer could release the effect of Cd stress on Zoysia japonica. For the effects of different nitrogen concentration on chlorophyll content of Zoysia （Chl a, Chl b, Chl a ＋ b）, stomata] conductance （Gs）, intercellular carbon dioxide concentration （ Ci ）, ]ear maximum quantum yield of PS Ⅱ （ Fv / Fro） and the electron transfer rate （ ETR）, it showed that treatment with 300 mg/kg nitrogen was the best, then 200 and 400 mg/kg. For the effects of different nitrogen concentration on net photosynthetic rate （Pn）, transpiration rate （Tr）, water use efficiency （WUE） and non-photochemical quenching （NPQ）, the result was that treatment with 300 mg/kg nitrogen was better than that of 400 and 200 ing/kg. However photochemical quenching （qP） was not significantly affected （P 〉0. 05） by nitrogen concentration. It was concluded that 300 mg/kg nitrogen concentration had the greatest effect on Zoysia japonica under cadmium stress in this study.