作 者 ：田治国1,王 飞2*

期 刊 ：西北植物学报 2013年 10期 页码：2057~2064

关键词：万寿菊；镉胁迫；光合特性；抗氧化酶；

Keywords:marigold, cadmium stress, photosynthesis, antioxidative enzymes,

摘 要 ：以6个万寿菊品种为研究对象,研究了不同浓度的重金属镉（Cd）胁迫（0、200、400、600 mg/L）对万寿菊基径、株高以及百叶重、茎叶重和单花质量等生长指标及其质膜透性（丙二醛、相对电导率）、保护酶活性（SOD、POD、CAT、APX）以及光合特性(叶绿素含量、净光合速率、气孔导度、蒸腾速率、水分利用效率)等生理指标的影响。结果显示:(1)低于400 mg/L的Cd胁迫对6个万寿菊品种的基径、株高无明显影响,而百叶重、茎叶重和单花质量却随着Cd浓度的增加显著降低,尤其是‘大英雄’和‘迪阿哥’2个品种表现的抗性较差。(2)随着Cd胁迫浓度的增加,各品种丙二醛（MDA）含量和相对电导率（REC）显著增加,而其保护酶活性不同程度降低。(3)Cd胁迫降低了万寿菊的叶绿素Chl a+b含量和Chl a/b,且抗性差的品种降低的幅度更大;叶片净光合速率（Pⁿ）明显降低,但蒸腾速率(T^r)和气孔导度(G^s)相对降幅较小,对水分利用效率（WUE）影响较小。研究表明,不同品种万寿菊对Cd毒害响应存在明显的差异,且Cd胁迫下生理响应的差异是品种间耐性差异的重要原因之一;抗性差的品种在高浓度Cd胁迫下,光合作用能力降低,抗氧化系统酶的活性受到显著抑制,膜质过氧化加剧,且品种‘珍妮’和‘金门’的抗性强于其他品种,可选择作为Cd污染区栽植植物。

Abstract:The effects of different cadmium levels（0,200,400,600 mg/L）on stem diameter,height,weight of hundred leaves,weight of stems and flowers,malondialdehyde (MDA),relative conductivity (REC),superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX),as well as photosynthetic parameters (Chl a+b,Pⁿ,G^s,T^r,WUE) were studied in six marigold cultivars.The results showed that:(1)No reduction in the stem diameter and height were noted when the plants were grown at Cd²⁺ supply levels up to 400 mg/L.However,fresh weight of hundred leaves stems and flowers of all cultivars were decreased with the increase of Cd²⁺ concentrations.Moreover,‘Great Hero’ and ‘Durango’were more sensitive than other cultivars.(2)MDA and REC were increased gradually as Cd²⁺ concentration increasing.However,the activities of antioxidative enzymes significantly changed with the increasing of Cd²⁺ concentrations from 0 to 600 mg/L.(3)Cadmium stress also caused Chl a+b and Chl a/b decrease,especially in Cd stress-sensitive cultivars.Moreover,Net photosynthetic rate decreased significantly under Cd stress,while the decrease of stomatal conductance (G^s),transpiration rate (T^r) and WUE were little.It was concluded that there was significant different response to Cd among marigold cultivars.The physiological characteristics of marigold responding to Cd might be important factors for the tolerance of cultivars.The photosynthetic efficiency and activities of antioxidative enzymes in sensitive cultivars were all decreased under Cd stress,which may cause lipid peroxidation to increase.In summary,‘Janie’and ‘Gate gold’had adaptation mechanism to Cd stress.The two cultivars are recommended for the heavy metal contaminated soils.