高浓度镉胁迫对茶树生理及吸收积累特性的影响

以名山白毫品种茶苗为材料,通过土壤盆栽实验,研究了高浓度镉胁迫对茶树生长、生理及吸收积累特性的影响。结果表明,土壤添加0~120mg/kg镉,茶树未表现出明显受害症状。但随镉胁迫浓度的增加,各器官生长量、叶绿素合成和光合作用均受到明显抑制;超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性均逐渐降低;丙二醛（MDA）、脯氨酸（Pro）含量以及相对电导率（RC）大幅上升。茶树各器官镉含量（y）与镉胁迫浓度（x₁）、土壤有效态镉含量（x₂）均呈显著或极显著性正相关关系,各器官镉积累量高低顺序为：细根>粗根>主茎>枝条>叶片>新梢。土壤中有效态镉向茶树迁移是各器官所积累镉的主要来源,镉在茶树体内大部分被细根、粗根固定,向地上部运输的比例较低。

Effect of High Concentrations of Cd Stress on the Physiological Characteristics, Absorbtion and Accumulation in Tea Plant

Through the soil pot experiment,investigation on the influence of high concentrations of cadmium stress on the growth,absorbtion and accumulation physical characteristics of tea plant by using Mingshanbaihao cultivar as testing material.The results showed that: Tea plants did not show obvious symptoms under the cadmium concentration of 0~120 mg/kg.The growth of various organs,chlorophyll synthesis and photosynthesis were significantly inhibited by increasing concentrations of Cd.Superoxide dismutase(SOD),peroxidase(POD),catalase(CAT) activity were gradually reduced accordingly.The content of malondialdehyde(MDA),proline(Pro) and relative conductivity(RC) increased substantially.Cadmium in various organs(y) had a significant or highly significant positive correlation with Cd concentration(x1) and available cadmium content in soil(x2).The order of cadmium contents in various organs was Fibrous roots> Roots> Stems> Branches> Leaves> New sterns>.The migration of available cadmium in soil from the underground parts to aboveground parts was the main source of cadmium in tea plants.Cadmium in tea plants mostly fixed by fibrous roots and roots,simultaneously,only a low ratio was transported to aboveground.