淹水胁迫下枫杨叶片对不同氮素水平的光合生理响应

Photosynthetic Physiological Response of Pterocarya stenoptera Leaves to Different Waterlogging Stress with Different Nitrogen Content

研究了不同氮素水平(16.0、6.0、0.5、0 mg/kg)没顶全淹、冠层半淹和根部渍水对枫杨光合作用的影响,结果表明,淹水使枫杨叶片的净光合速率(Pn)显著下降,但高氮(16.0 mg/kg)和中氮(6.0 mg/kg)淹水胁迫下枫杨叶片净光合速率的降幅明显低于低氮(0.5 mg/kg)和对照(0 mg/kg);淹水胁迫下,枫杨叶片的非光化学淬灭系数(qN)随氮水平的提高而降低,而光化学荧光淬灭系数(qP或qL)则相反。试验结果说明富氮可缓解淹水对枫杨叶片光合作用的胁迫损害。

Experiments were made on Pterocarya stenoptera under fully flooded, canopy semi-submerged and roots waterlogging with different nitrogen contents （16 mg/kg, 6 mg/kg, 0.5 mg/kg, 0 mg/kg）. The results showed that net photosynthetic rate （ Pn ）in leaves of P. stenoptera decreased significantly under any flooding treatment, and that decreased much lower with high and medium nitrogen content （16mg/kg, 6mg/kg）than with low content （0.5mg/kg） and control. （0 mg/kg）. Under flooding stress, non-photo chemical quenching coefficient（qN） decreased with the increase of nitrogen content, while photo chemical quenching coefficient （qp） was the opposite. The experiment demonstrated that higher nitrogen content could decrease the damage of waterlogging to photosynthesis in leaves of P. stenoptera.