水体营养盐质量浓度对苦草光合荧光特性的影响

通过室内培养，利用水下饱和脉冲荧光仪(Diving-PAM)研究了不同质量浓度的营养盐对苦草光合荧光特性的影响. 结果表明:①水体中N，P营养盐质量浓度的高低对苦草叶片PSⅡ和F_v/F_m影响不显著(P＞0.05). ②在日变化过程中，各处理组苦草的ΔF_v/F_m′均呈升—降—升的变化趋势，但方差分析显示，水体ρ(TN)和ρ(TP)变化不直接影响苦草的ΔF_v/F_m′(P＞0.05).③试验第4天各处理组的苦草叶片光响应能力大小依次为处理组B＞处理组C＞处理组D＞处理组A；在苦草生长初期，质量浓度较高的营养盐可以提高苦草叶片的光响应能力和捕光能力，并可增强叶片的光合活性；从整个试验过程来说，分别是处理组B的ρ(TN)和处理组C的ρ(TP)更利于苦草的生长. 

Effect of Water Nutrient Concentration on Photosynthetic Fluorescence Characteristics of Vallisneria natans

The effect of water nutrient concentration on photosynthetic fluorescence characteristics of Vallisneria natans was studied using Diving-PAM. The experiment was studied on water samples incubated inside. The results were as follows: (1) The water nutrient concentration had no significant influence on photosystem Ⅱ and F_v/F_m of Vallisneria natans (P＞0.05). (2) During diurnal variation, the Vallisneria natans's ΔF_v/F_m′ of treatment groups showed an up-down-up trend. Variance analysis showed that the water nutrient concentrations of TN and TP had no significant influence on ΔF_v/F_m′ of Vallisneria natans (P＞0.05). (3) In the 4th day of the experiment, the order of light-responding ability of Vallisneria natans's leaves in different groups was: Treatment B＞Treatment C＞Treatment D＞Treatment A. In early experiments, the higher nutrient concentration couldimprove the light response ability and the light-harvesting capacity of Vallisneria natans's leaves, and enhance the photosynthetic activity of the leaves. Within the entire experiment, the level of water nutrient concentration in B treatment group and C treatment group were better for the growth of Vallisneria natans.