作　　者： ; ; ;

机构地区： 华南师范大学化学与环境学院环境科学研究所

出　　处： 《生态环境》 2007年第3期775-778,共4页

摘　　要： 利用荧光成像技术研究了营养液培养条件下砷胁迫对蜈蚣草光合作用的影响。在0、5、10、20和40mg·L^-1质量浓度的砷处理中,蜈蚣草地上部、地下部生物量无显著差异（P=0.01）,变化范围分别为1.24～1.33,0.24～0.30g;地上、地下部砷质量分数变化范围分别为191～1129和160～548mg·kg^-1,其质量分数的比值范围为1.20～2.35。砷胁迫下,全叶片蜈蚣草Fv/Fm变化范围为0.498～0.566,与对照（0.786）相比较下降超过30%;快速光曲线中最大潜在相对电子传递速率（Pm）、半饱和光强（Ik）随砷处理浓度的增加而下降,其变化范围分别为24.52～47.67和140.50～217.45μmol·m^-2·s^-1,下降比例分别为28%-49%和24%-35%;快速光曲线的初始斜率（α）随砷处理浓度的增加下降不明显,变化范围为0.17～0.22。以上结果显示尽管蜈蚣草对砷超量吸收并且有效向地上部分转移,但Fv/Fm显著下降反映蜈蚣草光合作用受到明显的砷胁迫。Pm、Ik的下降反映出蜈蚣草光耐受能力和电子传递能力在砷胁迫下逐渐减弱;α下降不明显反映蜈蚣草捕光能力在砷胁迫过程中始终维持较高水平,砷胁迫并未对蜈蚣草捕光系统造成显著伤害。 By imaging-PAM, Photosynthetic performance of Pteris vittata was studied under Arsenic （As） stress. Under nutrient solution culture, biomass of shoots and roots ofP. vittata exposed to As showed no significant difference with the ranges of 1.24 - 1.33 and 0.24 - 0.30 g, respectively. As concentrations in shoots and roots varied from 191 to 1 129 mg/kg and from 160 to 548 mg/kg, respectively. The ratio of As concentration in shoots to roots in P. vittata varied from 1.20 to 2.35. Under 0-40 mg/L As treatments, Fv/Fm of P. vittata compared to controlled treatment decreased more than 30% with the range of 0.498 - 0.566; Pm and Ik ofP. vittata decrease from 28%-49% and 24%-35%, respectively. The ranges for Pm and lk were 24.52 - 47.67and 140.50 - 217.45μmol·m^-2·s^-1, respectively. No significant decrease of at was determined exposed to different As treatment with the range of 0.17 - 0.22. The above results indicated that P. vittata had the ability of absorbed and translated extraordinary As from roots to shoots, but photosynthesis were seriously inhibited under As stress reflected by decrease of Fv/Fm, Pm and lk, while the ability of light fixation of P. vittata kept efficiency reflected by constant at during As exposure.

关 键 词： 蜈蚣草 砷 叶绿素荧光成像 光合作用 快速光曲线

领　　域： [环境科学与工程]