• 研究报告 •

### 水体N/P对塔玛亚历山大藻响应紫外辐射的影响

1. (1温州医科大学生命科学学院海洋生物技术系， 浙江温州 325035； 2浙江省海洋水产养殖研究所， 浙江温州 325005)
• 出版日期:2016-02-10 发布日期:2016-02-10

### Effect of water N/P ratio on the response of Alexandrium tamarense to UV radiation.

LI Lei1, GUAN WAN-chun1, CHEN Shao-bo1,2, XIE Qi-lang1*

1. (1Department of Marine Biotechnology, School of Life Science, Wenzhou Medical University, Wenzhou 325035, Zhejiang, China; 2Zhejiang Mariculture Research Institute, Wenzhou 325005, Zhejiang, China)
• Online:2016-02-10 Published:2016-02-10

Abstract: Alexandrium tamarense, a typical species around China coastal water zone, was cultured under conditions of five N/P ratios (1∶1, 16∶1, 50∶1, 100∶1, 200∶1) for 14 days. The growth rates and pigment contents were measured at the end of the experiment. Then the cultures were exposed under three types of radiation (visible light, P; visible light + ultraviolet A, PA; visible light + ultraviolet A+B, PAB). The effective photochemical efficiency and exposure response curves (ERC) were detected after 60min exposure. The results showed the fastest growth rate and highest pigment contents (Chl-a: 3.06×10-5 μg·cell-1 and Caro: 2.10×10-5 μg·cell-1) were observed in the 16∶1 (N/P) treatment. However, the growth rates and pigment contents declined significantly when the N/P ratio in the media increased or decreased. The growth rate was a function of N/P ratio according to a twoorder equation (R2>0.98). The variation of effective photochemical efficiency was fitted well by a firstorder exponential equation (R2>0.97). The effective photochemical efficiency decreased under PA and PAB treatments compared to that under P treatment. There was a negative linear relationship between the decreased degree of the effective photochemical efficiency and the ratio of algal cell photosynthetic system II D1 protein repair rate and damage rate (r/k) (R2>0.98). The dependency of UVinduced photoinhibition in A. tamarense on the N/P ratio was fitted well by a two-order equation (R2>0.95). The r/k ratio was the highest and the decreased degree of the effective photochemical efficiency and the photoinhibition rate were the lowest in the 16∶1 (N/P) treatment. Therefore, the N/P ratio of 16∶1 is the optimum condition for the algal cells to defense the UVinduced photoinhibition by the alteration of r/k ratio.