Diurnal changes in photosynthesis by six submerged macrophytes measured using fluorescence
Diurnal changes in photosynthesis by six submerged macrophytes measured using fluorescence
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使用荧光测量六种沉水植物光合作用的昼夜变化
DOI：
10.1016/j.aquabot.2018.05.003
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发表时间：
2018-10-01
期刊：
影响因子：
1.8
通讯作者：
Huang, Wenmin
中科院分区：
文献类型：
--
作者：
Jiang, Hong Sheng;Zhang, Yizhi;Huang, Wenmin
陆生植物叶绿素荧光的日变化已得到充分研究，并显示出夏季中午的减弱。然而，尽管沉水植物在浅湖中发挥着重要作用，但对它们的研究却很少。本研究选择了六种常见的沉水植物来研究夏季晴天光系统II最大潜在量子效率（Fv/Fm）的日变化。在自然条件下，所有这些物种的Fv/Fm值在中午都有所下降，但无论是在“遮荫”处理下还是在实验室条件下都没有显着变化。 Fv/Fm 值与光子辐射率呈负相关，但金鱼藻除外，如快速光曲线所示，金鱼藻可能可以支持高光。陆生植物中午 Fv/Fm 值下降是由于光系统 II 对高辐照度的响应下调或光损伤引起的，这一点在沉水淡水植物中也得到了证实。在苦草中，除了中午的光抑制之外，还显示出昼夜节律的附加成分。研究沉水植物叶绿素荧光时应考虑昼夜节律和光子辐照度的日变化。
The diurnal changes of chlorophyll fluorescence of terrestrial plants have been well studied and show a midday depression in summer. However, only a few studies have been performed on submerged macrophytes though they play important roles in shallow lakes. In the present study, six common submerged macrophytes were chosen to investigate the diurnal changes of the maximum potential quantum efficiency of photosystem II (Fv/ Fm) on sunny days in summer. The Fv/Fm values of all these species decreased at midday under natural conditions, but there was no significant change either under the "Shade" treatment or under laboratory conditions. The Fv/Fm values were negatively correlated with photon radiance, except for Ceratophyllum demersum, which probably could support high light as shown by rapid light curves. The decreasing Fv/Fm values during midday known in terrestrial plants to be caused by either down-regulation or photodamage of photosystem II as a response to high irradiances was here also demonstrated for submerged freshwater macrophytes. In Vallisneria denserrulata showed an additional component of circadian rhythm to the midday photoinhibition. Circadian periodicity and the diurnal changes of the photon irradiance should be considered when investigating the chlorophyll fluorescence of submerged macrophytes.