不同氮素水平下CO_2倍增对大豆叶片荧光诱导动力学参数的影响

EFFECTS OF DOUBLED CO_2 ON THE FLUORESCENCE INDUCTION KINET1CS MRAMETERS OF SOYBEAN LEAVES GROWN AT DIFFERENT NITROGEN NUTRITION LEVELS

本文研究了在不同氮素水平下，CCO_2倍增对大豆叶片单位鲜重叶绿素（Chl）和类胡萝卜素（Car）含量，以及荧光诱导动力学参数的影响。结果表明，在正常大气下增施氮肥，对叶片Chl含量的提高作用相当于CO_2倍增的作用，但是增施氮肥又可进一步强化CO_2倍增的作用。CO_2倍增和增施氮肥均有改善大豆光合功能的作用，提高大豆的PSⅡ活性和光合作用潜在量子转化效率，提高PSⅡ反应中心开放部分的比例，降低非辐射能量的耗散，使大豆能更充分地利用所捕获的光能用于光合作用，结果促进PSⅡ总的光化学量子产量的提高。增施氮肥同样表现出可增强CO_2倍增对光合功能的改善作用。表明要使高浓度的CO_2对C_3植物光合作用起更好的作用，增施氮肥是必要的。

Effects of doubled CO_2 on the contents of chlorophyll and carotenoid in unit fresh weight of leaves and the fluorescence induction kinetics parameters of soybean grown under different nitrogen nutrition levels were studied in this paper. The experimental results showed that the content of chlorophyll was raised by the application of nitrogenous fertilizer and doubled CO_2, respectively. However. the action of duobled CO_2 can be strengthened by the application of nitrogenous fertilizer.The photosynthetic functions of soybean can be improved by doubled CO_2 and the application of nitrogenous fertilizer, respectively. PSII activity and the efficiency of potential photosynthetic quantum conversion of a leaf, the proportion of PSII reaction center opened part were raised and the dissipation of non-radiation energy was reduced by doubled CO_2 and the application of nitrogenous fertilizer under atmospheric CO_2,respectively. Therefore, light energy captured by leaves can be fully utilized for their photosynthesis. As a result of it, the overall photochemical quantum yield of PSII was raised. The photosynthetic functions improved by doubled CO_2 can be also promoted by the application of nitrogenous fertilizer. It shows that nitrogenous fertilizer should be applied when C_3 plants are grown under the environment of high CO_2 concentration.