| 摘要: |
| 【目的】研究桤木（Alnus cremastogyne）幼树在不同水平镉（Cd）胁迫下生长和抗性生理指标的变化，探索将桤木作为植物修复材料对Cd污染土壤进行修复的可行性。【方法】以1年生桤木幼树为试验材料，采用盆栽控制试验，设置0（CK），12.5，25，50 和100 mg/kg 5个Cd处理水平，以CdCl2·2.5H2O形式进行Cd胁迫，测定不同处理桤木幼树的生长和抗性生理指标。【结果】①与CK相比，桤木幼树的株高和地径生长量除12.5 mg/kg Cd处理略有升高外，其余处理随胁迫程度加重均显著下降；不同Cd胁迫处理各器官（根、茎、叶）生物量、总生物量、根冠比、根系活力也均低于CK。② Cd胁迫处理下，桤木幼树叶片中过氧化氢（H2O2）和丙二醛（MDA）含量均较CK上升，除12.5 mg/kg Cd处理与CK差异不显著外，其余处理均与CK差异显著；随着Cd胁迫水平提高，超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）活性均呈先升后降趋势，且均以12.5 mg/kg Cd处理最高。③ 桤木幼树叶片中脯氨酸（Pro）和可溶性蛋白（SP）含量随Cd胁迫水平提高呈先升后降趋势，可溶性糖（SS）含量呈持续上升趋势，且Pro、SP和SS（100 mg/kg Cd处理除外）含量均高于CK。④ 桤木幼树各器官中的Cd含量总体随Cd胁迫水平提高呈上升趋势，各器官Cd含量排序为吸收根>运输根>枝>茎>叶；同一Cd处理水平下，地下部的Cd含量和Cd富集系数远高于地上部，但总体偏小，对Cd的转移效率较低。【结论】桤木幼树对Cd胁迫的耐受能力有限，Cd胁迫会对其生长发育产生明显抑制，且桤木幼树对土壤中Cd的富集和转移能力有限，因此不宜将桤木幼树用于Cd污染土壤的修复。 |
| 关键词: 桤木 镉胁迫 生长 抗性生理 |
| DOI：10.13207/j.cnki.jnwafu.2025.09.008 |
| 分类号: |
| 基金项目:2020年四川省科技厅项目(2016NYZ0035) |
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| Responses of growth and resistant physiology of Alnus cremastogyne saplings to cadmium stress |
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LI Chuang, HU Hongling, ZHANG Chenghao, DENG Wen, LI Donghao, CHEN Gang
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State Forestry and Grassland Administration Key Laboratory of Forest Resource Conservation and Ecological Safety in the Upper Yangtze River,Sichuan Provincial Key Laboratory of Forestry Ecological Engineering in the Upper Yangtze River,College of Forestry,Sichuan Agricultural University,Chengdu,Sichuan 611130,China
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| Abstract: |
| 【Objective】The study aimed to examine the impact of varying levels of cadmium (Cd) stress on the physiological indices of growth and resistance of Alnus cremastogyne saplings,and to assess the potential of alder as a phytoremediation material for the remediation of Cd-contaminated soil.【Method】The physiological indices of growth and resistance of Alnus cremastogyne saplings in different treatments were determined by means of controlled pot experiment with five Cd treatment levels ( 0(CK),12.5,25,50 and 100 mg/kg),and Cd stress was achieved in the form of CdCl2·2.5H2O.【Result】① In comparison to CK,the plant height and ground diameter growth of Alnus cremastogyne saplings exhibited a notable decline with the escalation of stress levels,with the exception of a slight increase observed in the 12.5 mg/kg Cd treatment.The biomass of various organs (roots,stems,leaves),total biomass,root/shoot ratio,and root vitality under different Cd stress treatments were also lower than CK.② The content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) in the leaves of Alnus cremastogyne saplings subjected to Cd stress treatments was elevated in comparison to the control (CK) in all treatments except the 12.5 mg/kg Cd treatment,which exhibited no statistically significant difference from CK.The activities of superoxide dismutase (SOD),catalase (CAT),and peroxidase (POD) firstly increased and then decreased with the elevation of Cd stress levels.Notably,these activities reached their highest levels in the 12.5 mg/kg Cd treatment.③ The contents of proline (Pro) and soluble protein (SP) in the leaves of Alnus cremastogyne saplings firstly increased and then decreased with the elevation of Cd stress levels.In contrast,the soluble sugar (SS) content exhibited a sustained upward trajectory.And the contents of Pro,SP,and SS were higher than that of CK in all treatments except the 100 mg/kg Cd treatment.④ The Cd content in each organ of Alnus cremastogyne saplings increased with the elevation of Cd stress levels.The Cd content in each organ was ordered as follows:absorbing roots>transporting roots>branches>stem.The Cd content and Cd enrichment coefficient of the underground organs were significantly higher than those of the aboveground organs under the same level of Cd treatment.However,the Cd content and Cd enrichment coefficient of the underground organs were generally low,and the efficiency of Cd transfer was relatively low.【Conclusion】The growth and development of Alnus cremastogyne saplings is significantly inhibited by Cd stress,and these plants have limited ability to enrich and transfer Cd from the soil.Therefore,the use of Alnus cremastogyne saplings for the remediation of Cd-contaminated soil is not an appropriate approach. |
| Key words: Alnus cremastogyne cadmium stress growth physiology of resistance |
