湖泊科学   2020, Vol. 32 Issue (1): 134-143.  DOI: 10.18307/2020.0113. 0

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GUAN Yue, ZHANG Min, ZHAO Xingqing. The trade-offs of functional traits in Microcystis (FACHB-905) and Anabaena (FACHB-82) responding to temperature. Journal of Lake Sciences, 2020, 32(1): 134-143. DOI: 10.18307/2020.0113.
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2019-06-05 收稿
2019-08-12 收修改稿

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(1: 常州大学环境与安全工程学院, 常州 213164)
(2: 中国科学院南京地理与湖泊研究所, 湖泊与环境国家重点实验室, 南京 210008)

The trade-offs of functional traits in Microcystis (FACHB-905) and Anabaena (FACHB-82) responding to temperature
GUAN Yue1 , ZHANG Min2 , ZHAO Xingqing1
(1: School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, P. R. China)
(2: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China)
Abstract: Microcystis and Anabaena are two major genera of bloom-forming cyanobacteria. The way in which the two cyanobacteria regulate their own morphology and physiological characteristics to maintain rapid growth is to explain the maintenance of two cyanobacteria blooms. In this study, the response of growth, morphological and photosynthetic characteristics of Microcystis (FACHB-905) and Anabaena (FACHB-82) to temperature changes were measured, and the trade-offs relationship between growth and these characteristics were analyzed. The results showed that the cell diameter of Microcystis decreased under high temperature, but the growth rate did not decrease under high temperature. These indicates that Microcystis could increase the growth rate by reducing the cell size under high temperature conditions. The cell diameter and the chain length of Anabaena changed significantly with the change of temperature. The chain length decreased significantly and the growth rate did not decrease under high temperature conditions, which suggests that Anabaena might regulate its morphological characteristics to maintain the high growth rate. At the same time, the specific growth rate of the two algae has a certain relationship with the photochemical activity, indicating that the two algae can adapt to the temperature change by weighing the relationship between their own morphology, photosynthetic characteristics and growth rate to obtain the best growth status. This study will be helpful to improve our understanding for the growth mechanism of cyanobacteria.
Keywords: Microcystis    Anabaena    temperature    trade-off    chain length

1 材料与方法 1.1 藻种培养

1.2 细胞及光合指标

 $F_{\mathrm{v}} / F_{\mathrm{m}}=\left(F_{\mathrm{m}}-F_{\mathrm{o}}\right) / F_{\mathrm{m}}$ (1)
 $F_{\mathrm{v}}^{\prime} / F_{\mathrm{m}}^{\prime}=\left(F_{\mathrm{m}}^{\prime}-F_{\mathrm{t}}\right) / F_{\mathrm{m}}^{\prime}$ (2)

1.3 比增长速率

 $\mu=\left[\ln \left(N_{n}\right)-\ln \left(N_{0}\right)\right] / t$ (3)

1.4 数据处理

2 结果分析 2.1 温度对两种藻比增长速率的影响

 图 1 不同温度条件下微囊藻(FACHB-905)和鱼腥藻(FACHB-82)的比增长速率 Fig.1 The specific growth rates of Microcystis (FACHB-905) and Anabaena (FACHB-82) cultured under different temperature conditions
2.2 不同温度下两种藻的细胞直径和鱼腥藻藻丝长度的变化

 图 2 不同温度条件下微囊藻(FACHB-905)和鱼腥藻(FACHB-82)细胞直径及鱼腥藻藻丝长度的变化 (a~c代表两种藻细胞形态在不同温度下的时间变化趋势，不同颜色的点和线代表不同温度组；d~f代表两种藻细胞形态在不同温度组间的均值差异，小写字母表示各组间的差异显著性) Fig.2 The variation of cell diameters of Microcystis (FACHB-905) and Anabaena (FACHB-82) and length of filaments of Anabaena (FACHB-82) cultured under different temperature conditions (a-c: the morphological change trends of two algae in different temperature groups during the experiment period. Different colors represent different temperature groups; d-f: the mean difference of the morphological in the two species of algae among different temperature groups. The letters indicate the significance among the groups)

2.3 不同温度下两种藻的光合特性变化

 图 3 不同温度条件下微囊藻(FACHB-905)和鱼腥藻(FACHB-82)光合活性的变化趋势 Fig.3 The variations of Fv/Fm and Fv′/Fm′ in Microcystis (FACHB-905) and Anabaena (FACHB-82) cultured under different temperature conditions

2.4 两种藻各功能特性之间的关系

 图 4 微囊藻(FACHB-905)和鱼腥藻(FACHB-82)形态特性与生长、光合活性间的关系(点的颜色表示培养时间；红色实线表示显著线性相关；红色虚线为loess回归线，且无线性相关；灰色区域表示95 %置信区间) Fig.4 The relationship between morphological traits and growth rate, photosynthesis parameters in Microcystis (FACHB-905) and Anabaena (FACHB-82) (Different colorful points represent different culture time. The red solid lines indicate significant linear relationship. The red dash line is the loess fitting line, and indicate non-significant linear relationship. The gray areas indicate the 95 % confidence interval)
3 讨论 3.1 不同温度下两种藻的生长分析

3.2 不同温度下两种藻的形态变化及其与生长速率之间的关系

3.3 不同温度对两种藻的光合特性影响及其与生长速率之间的关系

4 结论

1) 微囊藻(FACHB-905)细胞直径在低温或高温条件下均有所降低，表明在不利条件下，其可能通过减小细胞直径的调节方式增大生长速率.

2) 鱼腥藻(FACHB-82)的细胞直径和藻丝长度在不同温度组中的变化趋势相反，高温下维持较高的生长速率，但细胞直径增大，藻丝长度缩短，这可能是鱼腥藻具有通过调节自身形态来维持较高生长速率的种群发展策略.

3) 两种藻均可以通过调节自身形态和光合活性来适应温度的变化以达到最佳的生长状态，微囊藻通过调节细胞大小和光合活性来维持生长优势，而鱼腥藻则通过权衡细胞直径、藻丝长度以及光合活性来维持生长优势，但两种藻的这些机理性研究结论仍有待在野外条件下进一步证实.

5 参考文献