光-暗循环中三角褐指藻和具齿原甲藻快速光曲线的变化  

CHANGES IN RAPID LIGHT CURVES OF PHAEODACTYLUM TRICORNUTUM AND PROROCENTRUM DENTATUM DURING LIGHT-DARK CYCLES

作　　者：韩志国[1] 雷腊梅[1] 韩博平[1] 

机构地区：[1]暨南大学水生生物研究所,广东广州510632

出　　处：《热带海洋学报》2005年第6期13-21,共9页Journal of Tropical Oceanography

基　　金：科技部"863"计划项目(2002AA515030);广东省科技攻关项目(2004B33401002);暨南大学博士学位论文创新项目

摘　　要：利用脉冲振幅调制叶绿素荧光仪研究了光-暗循环中三角褐指藻Phaeodactylum tricornutum和具齿原甲藻Prorocentrum dentatum的快速光曲线变化。在光-暗循环中2种藻的快速光曲线呈周期性变化,但具齿原甲藻的最大相对电子传递速率始终快于三角褐指藻,前者是后者的1.8—2.6倍。照光后三角褐指藻和具齿原甲藻的光合参数α和Pm迅速上升到最大值,在随后的光照期间α和Pm逐渐下降,经12h暗适应后恢复到初始值,呈明显的周期变化。这种变化可能受外界光强和生物节奏双重调节。光系统Ⅱ的有效量子产量随光合有效辐射(PAR)升高而下降,但在光照期间PAR较低时存有效在量子产量随PAR升高而升高的现象,这可能是由“状态转换”或叶绿体呼吸引起的。在光-暗循环中,2种藻的α均有较高的变异系数,说明利用固定光合参数计算初级生产力得到的误差中α的贡献较大。Changes in rapid light curves of Phaeodactylum tricornutum and Prorocentrum dentatum during light-dark cycles were studied with Pulse-Amplitude-Modulation Chlorophyll Fluoremeter. The results showed that the rapid light curves of both algae had diel changes during light-dark cycles. The maximum of relative electron transport rate of P. dentatum was 1.8-2.6 times of P. tricornutum. During the light phase, the photosynthetic coefficients a and Pm increased to maximum at the first hour of the light phase, then began to decrease. The changes in a and Pm may be caused by both exogeneous irradiance and endogenous rhythms. During light-dark cycles, the effective quantium yield of photosystem Ⅱ decreased with the increase of Photosynthetically Active Radiation （PAR）. However, when PAR was less than 100 μmol · （m^2 · s）^-1 during the light phase, the quantum yield increased with the increase of PAR, which may be caused by ＂state transition＂ or chlororespiration. The variation coefficient of a was larger than those of other photosynthetic coefficients in both algae during light-dark cycles. The results indicate that a may contribute more than other coefficients to the large changes in calculated primary production.

关 键 词：快速光曲线 叶绿素荧光 三角褐指藻Phaeodactylum TRICORNUTUM 具齿原甲藻Prorocentrum dentatum 

分 类 号：Q945.11[生物学—植物学]