• 研究论文 •

### 绿狐尾藻光合色素组成及氮磷化学计量学特征对外源铵的响应

1. 1中国科学院亚热带农业生态研究所, 农业生态系统过程重点实验室, 长沙农业环境观测研究站, 长沙 410125
2华中农业大学资源与环境学院, 武汉 430070
3湖南农业大学资源环境学院, 长沙 410128
• 收稿日期:2021-08-11 接受日期:2021-10-18 出版日期:2022-04-20 发布日期:2022-01-30
• 通讯作者: 李宝珍
• 作者简介:*(bzli@isa.ac.cn)
ORCID: 冼应男: 0000-0003-2163-8196
• 基金资助:
国家自然科学基金(42077103);湖南省水利科技项目(XSKJ2019081-52);湖南省国际科技创新合作基地项目(2018WK4012)

### Responses of photosynthetic pigments composition, nitrogen and phosphorus stoichiometric characteristics of Myriophyllum aquaticum to exogenous ammonium

XIAN Ying-Nan1,2, ZHANG Ying1,3, LI Bao-Zhen1,*(), LUO Pei1, XIAO Run-Lin1, WU Jin-Shui1

1. 1Key Laboratory of Agro-ecological Processes in Subtropical Region, Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
2College of Resources & Environment, Huazhong Agricultural University, Wuhan 430070, China
3College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China
• Received:2021-08-11 Accepted:2021-10-18 Online:2022-04-20 Published:2022-01-30
• Contact: LI Bao-Zhen
• Supported by:
National Natural Science Foundation of China(42077103);Project of Water Science and Technology in Hunan Province(XSKJ2019081-52);Hunan Provincial International Science and Technology Innovation Cooperation Base Project(2018WK4012)

Abstract:

Aims Myriophyllum aquaticum has high tolerance to high concentration of ammonium (NH4+) and thus becomes the preferred species for swine wastewater treatment. It is of great significance to explore the effects of exogenous NH4+ on the photosynthetic pigment composition and the stoichiometric characteristics of nitrogen (N) and phosphorus (P) of the M. aquaticum for improving the purifying efficiency of artificial wetlands system of M. aquaticum.

Methods Six NH4+ concentration levels (0, 0.1, 1, 5, 15, 30 mmol·L-1) were set up in this study. After 21 days of indoor cultivation, the contents of chlorophyll, N and P of M. aquaticum were measured to analyze their characteristics of changes.

Important findings The results showed that the relative stem height and biomass increased initially and then decreased, which were well fitted by a curve equation. Moreover, the peak of them appeared at 16.22 and 12.58 mmol·L-1 exogenous NH4+, respectively, via fitting non-linear Gaussian equation. With the increase of exogenous NH4+ concentrations, the chlorophyll content in the leaves decreased significantly, but increased in the stems. In addition, there was a wide variation of chlorophyll a than chlorophyll b. The chlorophyll a/b did not change significantly among different NH4+ treatments, except the value in the stems of 5 mmol·L-1 NH4+ treatment, which was significantly decreased. With the increase of exogenous NH4+ concentrations, the N contents in the leaves and stems were significantly increased by 85%-235% and 127%-373%, respectively, and the P content in the leaves was increased by 49%-51% in comparison to the control (CK). When the concentrations of exogenous NH4+ was no more than 15 mmol·L-1, the N content and N:P ratio of the leaves and stems increased rapidly, so were relative stem height and relative biomass. Correlation analysis showed that the contents of N and P, and N:P ratio were negatively correlated with total chlorophyll content in the leaves, but positively correlated with total chlorophyll content in the stems. In conclusion, M. aquaticum grew well with larger biomass and higher absorption of N and P, when the concentrations of exogenous NH4+ were in the range of 12-16 mmol·L-1. Therefore, the constructed wetlands system planted with M. aquaticum can effectively remove N and P from polluted wastewater and achieve the purpose of efficient water purification.