【作者】 娄玉霞； 于晶； 曾元元； 曹同；

【Author】 Yu-Xia Lou Jing Yu Yuan-Yuan Zeng Tong Cao (Life and Environment Science College,Shanghai Normal University,Shanghai 200234)

【机构】 上海师范大学生命与环境科学学院；

【摘要】 利用人工移植盆栽结合人工喷雾处理的方法,包括对照在内,共设置11个不同浓度的Pb处理,研究Pb污染对匐枝青藓（Brachythecium procumbens）各种色素含量及净光合速率的影响。结果表明,匐枝青藓不同的光合色素对铅污染的响应敏感性不同,叶绿素a和类胡萝卜素都很敏感,叶绿素b相对较差。短时间（7d）和低浓度的铅污染(0.2-0.5mmol·L^-1)时,匐枝青藓配子体中各种光合色素的含量显著高于对照。随着铅污染时间的延长（≥14d）和浓度的增高,各种光合色素含量则随着铅浓度升高而逐渐下降。铅污染时间越长,浓度越高,光合色素含量降低幅度越大,其中叶绿素a含量降低最为关键。匐枝青藓的净光合速率在铅污染状态下也发生了显著变化,短时间污染下,随着铅污染浓度增高呈现出明显的先升后降的趋势,但长时间高浓度铅污染时,其下降速度和幅度更大,与对照相比,50%净光合速率的铅污染浓度阈值更低。匐枝青藓配子体各种光合色素的含量变化和净光合速率的变化可以作为监测环境重金属铅污染的生理指标,进行长期指示区域环境重金属铅污染的状况.更多还原

【Abstract】 In order to understand the influence of Pb pollution on photosynthetic pigments and net photosynthetic rate of Brachythecium procumbens,11 groups including contrast were set up with different Pb concentrations.The sensitivity of different photosynthetic pigments to Pb pollution was different,both chlorophyll a and carotenoid were sensitive to Pb while chlorophyll b was not obviously sensitive to Pb.Treated with Pb of 0.2-0.5 mmol-L-1,the contents of photosynthetic pigments in the gametophyte of Brachythecium procumbens were significantly higher than contrast with short treatment time(7d).By extending time(≥14d) and increasing the Pb concentration,the contents of photosynthetic pigments decreased gradually.The longer polluting time with the higher polluting concentration,the decreasing extent of the contents of photosynthetic pigments was more obvious.Among all photosynthetic pigments,the decrease of the content of chlorophyll a was the most obvious.On the other hand,the net photosynthetic rate of Brachythecium procumbens changed obviously under the pollution of Pb.If the polluting time was short,the content of net photosynthetic rate increased first and decreased then.While polluted with higher concentration and longer time,the pigments content decreased more quickly and obviously.Compared with the contrast,the threshold value of the Pb concentration of 50%net photosynthetic rate was much less.According to the above result,we think that the changes of the contents of photosynthetic pigments and the net photosynthetic rate of the gametophyte of Brachythecium procumbens could be applied as the physiological indices to Pb contamination and environmental evaluation in regional environment.更多还原