摘要
用粒径小于100μm的泥沙分别配置浊度为30、60和90NTU的浑浊水体,将苦草(Vallisneria natans)幼苗种植于上述水体中,测定幼苗的叶片长和叶片数,并利用水下饱和脉冲荧光仪(DIVING-PAM)测定幼苗的光合荧光特性,研究在不同浊度水体中水下光强对苦草幼苗生长的影响。结果表明,随着处理时间的延长和水体浊度的增大,苦草幼苗生长受到明显的影响。第30天时,在60和90NTU水体中,水下光强不足自然光强的4.5%,幼苗叶片出现发黄、折断现象,相对电子传递速率和饱和光强显著降低,非光化学淬灭系数显著升高,表明幼苗光合作用受到明显抑制。在对照水体中,水下的光强为水面光强的43.3%以上,苦草幼苗也受到抑制;而在水下光强≥7.1%的30NTU水体中,苦草幼苗有较高的光能利用率,幼苗生长较好。这表明苦草幼苗有一定的低光适应能力,光强范围大约是7.1%～43.3%,为在浑浊水体中恢复、重建苦草种群提供了一定的实验依据。
Seedlings of Vallisneria natans were planted in waters with different turbidities of 30 NTU, 60 NTU and 90 NTU. Such turbidities were made by mud and sand particles below 100 μm in diameter. Photosynthetic fluorescence characteristics were measured by a developed submersible pulse-amplitude modulated （PAM） fluorometer, Diving-PAM. The longer exposure time and higher turbidity affected the growth of the seedlings markedly. After 30 day exposure at the turbidities of 60 NTU and 90NTU, the seedlings＇ leaves became yellow and broken, and the relative Electron-transport rate （rETR） and saturated light decreased remarkably, and the Non-photochemical Quenching （NPQ） increased evidently, indicating that the photosynthesis of seedlings＇ was inhibited. The seedlings of Vallisneria natans were also restrained in the control where underwater light intensity was more than 43.3% of natural light intensity, but the seedlings grew well in the water at turbidity of 30NTU where underwater light intensity was more than 7. 1 %.These results indicated that the seedlings of Vallisneria natans were adapted to low intensity which ranged from 7. 1 % to 43.3% of natural light intensity.
出处
《生态环境》
CSCD
北大核心
2007年第3期762-766,共5页
Ecology and Environmnet
基金
教育部科技创新工程重大项目培育基金项目(705824)
江苏省重点科技专项项目(BM2002701)
国家863"十五"重大科技专项项目(2003AA601100-2)
国家"十五""211工程"重大项目
