漳江口优势红树植物秋茄叶绿素荧光特性对盐度环境的响应

利用HandyPEA植物效率仪对生长在漳江口红树林湿地国家级自然保护区内不同盐度环境中（样地FZ1、FZ2、FZ3、FZ4）优势红树植物秋茄的叶绿素荧光特征进行了研究，结果表明：初始荧光F0各样地之间无显著差异，最大荧光Fm、可变荧光F。均为生长在样地3（盐度为15．60‰～20．08‰）的最高，Fv／Fm、Fv／Fo和PIABS表现出同样的规律：样地4最低（盐度20．58‰～23．54‰），样地2、3较高且与样地4水平差异有统计学意义（P〈0．01）；从叶绿素荧光诱导动力学曲线（O—J—I—P）的变化情况，曲线起始部分的变化不大，其余部分均是样地3比其他三个样地高．比活性参数ABS／CS和TR0／cs在样地3最高；而DI0／CS、ET0／cs和RC／CS0在样地间差异无统计学意义．说明在样地3的盐度环境中下，光系统Ⅱ的电子传递能力最强，更有利于光合器官对光能的吸收、转化，具有更高的光合效率．

Response of Chlorophyll a Fluorescence of Kandelia Obovata to Salinity Environments in Zhangjiang Estuary

Kandelia obovata is the dominant species of the mangrove in the Natural Mangrove Wetland Reserve in Zhangjiang Estuary. We investigate the chlorophyll a fluorescence transients of Kandelia obovata,which grows in different environments with various contents of salinity （Sample plots of FZ1, FZ2, FZ3 and FZ4 ） in the Wetland Reserve using the plant efficiency instrument Handy PEA. The results show that there is no significant difference in initial fluorescence Fo among different samples.The values of maximum fluorescence Fm, variable fluorescence Fv, Fv/Fm, Fv/Fo and PIabs are the highest in the samples from FZ3 with a salinity of 15. 60% - 20. 08 %and the lowest in the samples from FZ4 with a salinity of 20.58%-23.54%.Their values are significant higher in samples from FZ2 and FZ3 than from FZ4 （P〈0.01）.Chlorophyll fluorescence transients show that there are no significant difference in O-step among different samples and the sample FZ3 has more pronounced J-, I-,and P-steps than the other three samples. Moreover, the phenomenological fluxs parameters ABS/ CS and TR0/CS of the sample FZ3 are higher than the other ones but no significant differences are found in DIo/CS, ETo/CS and RC/CS among samples from different salinity environments. These results indicate that the electron transfer capacity of photosystem II is the highest in the samples from FZ3, facilitating light absorption and transformation of photosynthetic organ, thus enhancing photo- synthetic efficiency.Therefore,the FZ3 is the optimum place suitable for the growth of the Kandelia obovata among the the four sample plots