中文摘要：

沉水植物穗花狐尾藻（Myriophyllumspicatum）能产生对水华蓝藻生长有抑制效应的酚类活性物质。为了揭示光照强度对穗花狐尾藻的生长及其体内酚类物质含量的影响，文章研究了不同光照强度下穗花狐尾藻的生物量及其顶端组织与茎中的可溶性糖、可溶性蛋白、总酚的含量以及与酚类代谢相关酶一苯丙氨酸裂解酶（Phenylalanineammonia-lyase，PAL）的活性，结果表明：穗花狐尾藻生物量随着光照强度的减弱而显著降低；高光照强度和中等光照强度下，顶端组织中可溶性蛋白、总酚含量和PAL酶活都明显高于茎中各指标；茎中的总酚含量、PAL酶活性在低光照强度下显著高于高光照强度和中等光照强度下。

英文摘要：

Submerged macrophyte Myriophyllum spicatum can produce polyphenols with strong inhibitory activity against the growth of Cyanobacteria. To explore the effects of light intensity on growth of M. spicatum and its phenolic production, the biomass, soluble sugar, soluble protein, contents of phenolics, activity of related enzyme phenylalanine ammonia-lyase （PAL） in apical meristems and stems of M. spicatum under different light intensities were investigated. Results indicated that the biomass of M. spicatum was significantly reduced when light intensity decreased. Under high and middle light intensity, contents of soluble protein, polyphenols and activity of PAL in apical meristems were significantly higher than those in stems. The phenolic contents, activity of PAL in stems under low light intensity were significantly higher than those under middle and high light intensity.