【摘要】 该文以苦草（Vallisneria natans）为材料,研究了不同浓度铜污染水体对其叶/根长、生物量、光合色素含量、体内重金属含量及叶绿素荧光参数的影响。结果表明:随着水体铜浓度的增加,苦草的叶长、根长、生物量均显著下降;光合色素含量逐渐下降,其中叶绿素a比叶绿素b下降明显,类胡萝卜素下降幅度最小;叶片铜含量随铜浓度的增加显著上升（P<0.05）,各处理组根铜含量没有显著性差异,在水中铜低于0.5mg·L^-1的环境中苦草具有正常的光合活性。除0.5 mg·L^-1处理组外,最大荧光（F_m）、最大光化学效率（F_v/F_m）、潜在光化学效率（F_v/F_o）、光化学淬灭系数（qP）与有效量子产量[Y（Ⅱ）]均比对照组显著降低（P<0.05）,而非光化学淬灭效率（qN）、调节性能量耗散的量子产量[Y（NPQ）]、非调节性能量耗散的量子产量[Y（NO）]均呈上升趋势,其中F_v/F_o对铜污染反应最为灵敏。综合各参数变化情况,随着水体铜浓度的增加,苦草生长受到抑制,叶片利用光能的效率下降,PSⅡ反应中心的电子传递受到明显的抑制;苦草通过自身调节以热的形式将过剩光能耗散,以减轻PSⅡ反应中心受伤害的程度;苦草是铜超富集植物,其可作为低浓度铜污染水体生态修复的备选物种。更多还原

【Abstract】 Vallisneria natans was selected as test materials and cultured in different concentrations of Cu polluted water. The lengths of leaves and roots,biomass,photosynthetic pigment,heavy metal content and chlorophyll fluorescence parameters of V. natans were observed. The results showed that the lengths of leaves and roots,biomass of V. natans were significantly decreased with the increase of Cu concentration. The leaves gradually lost chlorosis,the chlorophyll a decreased more than the chlorophyll b,and carotenoids had the smallest decline. Cu content in the leaves of V. natans increased significantly（ P<0.05） with the increase of Cu concentration,and there was no significant difference in Cu content of roots between treatment groups. V. natans has normal photosynthetic activity when Cu was less than 0.5 mg·L^-1 in water. Except for the 0.5 mg·L^-1 treatment group,F_m,F_v/F_m,F_v/F_o,qP and Y（Ⅱ） were significantly lower than the control group（ P<0.05）,while qN,Y（ NPQ） and Y（ NO） showed an upward trend,in which Fv/Fowas the most sensitive to Cu pollution. In summary,the growth of V. natans was inhibited with the increase of Cu concentration,the efficiency of utilizing light energy of leaves was decreased,and the electron transfer of PSⅡreaction center was obviously inhibited. V. natans consumed excess light energy in the form of heat through self-regulation,to reduce the extent of damage to PSⅡreaction center. V. natans was a Cu hyperaccumulator which can be used an alternative species for ecological restoration of low-Cu-polluted water.更多还原