摘要
用粒径小于100μm的泥沙分别配置浊度为30、60和90NTU(Nephelometric Turbidity Units)的混浊水体,将穗花狐尾藻(Myriophyllum spicatum L．)成体植株分别种植于上述水体中,2个月后,利用水下饱和脉冲荧光仪(Diving-PAM)测定植株叶片的叶绿素荧光参数．结果表明,水体悬浮泥沙对狐尾藻成体植株F_v/F_m和F_o影响不显著,植株PSⅡ无显著损伤．用30μmol photon/(m^2·s)的光化光照射10s,在30和60NTU的混浊水体中植株△F_v/F_m、q^P和rETR与对照的差异不显著;在90NTU的水体中,q^P、rETR与对照的差异显著(P＜0．05);q^N值≤0．1,表明在低光化光照射下叶片的热耗散少,能量更多的参与了光化学反应．在悬浮泥沙水体中植株的rETR日变化幅度显著小于对照,植株的光合作用随水体浊度的增加显著降低．F_v/F_m日变化呈较为平缓的“V”形变化,植株受到的光抑制程度低;泥沙浊度≥60NTU时,F_v/F_m恢复变慢,但与对照差异不显著,rETR_(max)随泥沙浊度升高呈下降趋势,光合作用能力显著降低．结果表明穗花狐尾藻是一种较为耐受悬浮泥沙水体的沉水植物,悬浮泥沙对植株光合系统PSⅡ、抗光抑制能力无显著影响,但对光合作用能力影响显著(P＜0．05)．
Mature Myriophyllum spicatum L. were planted respectively in 30NTU, 60NTU and 90NTU turbid water of suspended sands. In these turbid waters, the size of suspended sands were less than 100μm. After two months, the leaves near their stems were measured by a newly developed, submersible, pulse-amplitude modulated （PAM） fluorometer. Diving-PAM. The results indicated that photosystem II of Myriophyllum spicatum didn＇ t damaged apparently in the turbid waters by the detection of Fv/Fm and Fo. After the leaves were illuminated by actinic light of 30μmol photon/（m^2·s） for 10 s, △Fv/Fm and q^P didn＇t decrease significantly in 30 and 60 NTU turbid waters less than those in the control water,while q^P in 90NTU turbid water was remarkably lower than that in the control water （p 〈 0. 05 ）. q^N in these turbid waters was less than 0. 1, indicating that heat dissipation of the plants was low, and more energy took part in light chemical reaction. In addition, the diurnal variational extent of rETR in turbid waters was smaller significantly than that in the control water, and photosynthesis of these plants significantly decreased with turbidity of water increasing. The diurnal variation of Fv/Fm under irradiance exhibited gentle ＂V＂ shape in the turbid water, indicating that MyriophyUum spicatum L. could endure higher irradiance. When turbidity of water was more than 60NTU, Fn/Fm of these plants restored slower than that of the control water, but their difference wasnt significant. Maximal rETR also decreased with the increasing turbidity of water, showing that photosynthesis ability of the plants decreased apparently. All above-mentioned results indicated that Myriophyllum spicatum L. , one kind of submerged macrophytes, was more tolerant to high turbid waters of suspended sands. Suspended sands didnt influence significantly photosystem and the tolerance to photoinhibitory stress, but did significantly photosynthetic ability of the plants （P 〈 0. 05 ）.
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2007年第2期197-203,共7页
Journal of Lake Sciences
基金
国家863"十五"重大科技专项(2003AA601100-2)
国家"十五""211工程"联合资助
关键词
穗花狐尾藻
悬浮泥沙
光合荧光特性
Myriophyllum spicatum
suspended sands
photosysthetic fluorescence characteristics
