Cd^(2+)、Hg^(2+)污染对香椿叶绿素含量和光合特性的影响  

Effects of Cd^(2+),Hg^(2+) Pollution on Contents of Chlorophyll and Photosynthetic Characteristics in Toona sinensis

作　　者：孟丽[1] 李德生[1] 茹丽叶[1] 王璠[1] 吴强 

机构地区：[1]天津理工大学环境科学与安全工程学院,天津300384 [2]天津市宁河县林业局,天津宁河300384

出　　处：《水土保持学报》2013年第5期240-243,共4页Journal of Soil and Water Conservation

基　　金：天津市科技支撑计划重点项目(12ZCZDNC00400);天津市农业科技成果转化与推广项目(0801160)

摘　　要：以红芽香椿(Toona sinensis)为材料,采用盆栽试验,研究不同浓度Cd2+、Hg2+单一处理对香椿叶片叶绿素含量和光合作用的影响。结果表明:香椿对低浓度Cd2+、Hg2+具有一定的抗性,叶绿素a和叶绿素b含量均高于对照,当超过一定浓度(Cd2+≥10mg/kg和Hg2+≥2mg/kg)时,叶绿素a和叶绿素b含量均呈下降趋势;叶绿素a/b在Cd2+胁迫时呈先上升后下降趋势,在Hg2+胁迫时总体呈上升趋势,与对照相比差异显著(P<0.05)。低浓度Cd2+、Hg2+处理时,香椿叶片净光合速率、蒸腾速率、气孔导度均升高,表现一定的促进作用。随着Cd2+、Hg2+处理浓度升高,香椿叶片净光合速率、蒸腾速率和气孔导度呈现下降的趋势,胞间CO2浓度升高。说明高浓度Cd和Hg胁迫下,非气孔因素是限制香椿光合作用的主要因素。In order to investigate the effects of different concentrations of Cd2＋,Hg^2＋ pollution on chlorophyll content and photosynthetic characteristics in leaves of Toona sinensis,apot experiment was carried out.The results showed that Toona sinensis had certain resistance to low concentrations of Cd2＋and Hg^2＋,the contents of chlorophyll a and chlorophyll b increased compared with the control.There was a downward trend as exceeding certain concentration（Cd2＋≥10 mg/kg and Hg^2＋≥2 mg/kg）.The content of a/b increased firstly and then decreased under the stress of Cd2＋.The content of chlorophyll a/b increased significantly under the stress of Hg^2＋（P0.05）.Low concentration of Cd2＋and Hg^2＋ had promoter action on net photosynthesis rate（Pn）,transpiration rate（E）and stomata conductance（Gs）.The Pn,E,Gs reduced with the increase of concentration of Cd2＋ and Hg^2＋,while the intercellular CO2 concentration（Ci） increased.It indicated that the factor of non stomatal factor was the main reason to inhibit the photosynthesis of Toona sinensis in high concentration of Cd2＋ and Hg^2＋.

关 键 词：香椿 Cd2+ Hg2+ 叶绿素 光合特性 

分 类 号：Q945.11[生物学—植物学]