| 磷、锌和镉交互作用对小白菜生长和锌镉累积的影响 |
| 摘要点击 1300 全文点击 459 投稿时间：2022-01-20 修订日期：2022-03-17 |
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| 中文关键词 镉(Cd) 磷(P) 锌(Zn) 交互作用 小白菜 |
| 英文关键词 cadmium(Cd) phosphorus(P) zinc(Zn) interaction Brassica campestris L. |
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| 中文摘要 |
| 利用不同元素之间的交互作用是控制作物重金属积累的有效手段.采用交替固定两因子的单一因子水平设计，以中性紫色土为材料，进行盆栽试验，探讨磷（P）、锌（Zn）和镉（Cd）不同水平组合对小白菜生长、抗氧化酶活性和Zn、Cd积累的效应和机制，为Cd污染土壤中蔬菜安全生产提供依据.结果表明，适量P和Zn的添加均能促进小白菜生长、抑制Cd在小白菜中的累积，但两者作用机制不同：P主要通过降低土壤中Cd的有效性和提高小白菜抗逆性减少小白菜对Cd的吸收，而Zn主要通过促进作物生长的稀释作用和植物体内生理拮抗作用抑制小白菜Cd的累积；外源添加1 mg ·kg-1 Cd胁迫时，小白菜抗氧化胁迫能力受到显著抑制，过氧化氢酶（CAT）和过氧化物酶（POD）活性下降，丙二醛（MDA）大量积累；P和Zn均可提高CAT活性而提高小白菜抗氧化胁迫能力，缓解Cd毒害，而对POD活性影响不大；外源添加P和Zn与Cd胁迫含量比ω（Cd）：ω（Zn）：ω（P）为1 ：10 ：200时，小白菜产量最大（55.72 g ·pot-1），且可食部Cd含量低于国家绿叶蔬菜中Cd限量50 μg ·kg-1的标准要求（GB 2762-2017）；增加P和Zn占比，Cd积累量进一步下降，但小白菜产量降低.因此适当施用P和Zn肥可降Cd并增产，实现蔬菜的安全生产. |
| 英文摘要 |
| The interaction between different elements is an efficient means to control the heavy metal accumulation in crops. Phosphorus (P) and zinc (Zn), as essential nutrient elements of plants, have been shown to have important impacts on cadmium (Cd) accumulation in crops through interactions with each other. However, the function of the simultaneous interaction of P, Zn, and Cd on vegetable growth and Cd accumulation remains unclear. Herein, using a single-factor level design with two alternating fixed factors, pot experiments were conducted to study the impact and mechanism of this simultaneous interaction at different levels of P, Zn, and Cd on Brassica campestris L. growth, antioxidant enzyme activity, and Zn and Cd accumulation with neutral purple soil as the substrate. The results showed that the addition of an appropriate amount of P and Zn could promote the growth of Brassica campestris L. and inhibit its Cd accumulation, through different mechanisms. P mainly reduced the Cd availability in soil and improved the crop resistance, whereas Zn mainly promoted the dilution effect by the crop growth and its physiological antagonism. The antioxidant capacity of Brassica campestris L. was significantly inhibited when 1 mg·kg-1 exogenous Cd was added to the soil, along with decreased activities of CAT and POD and high accumulation of MDA. Notably, both P and Zn could improve the antioxidant capacity and relieve Cd toxicity by increasing CAT activity, without obviously influencing POD activity. The highest yield of Brassica campestris L. (55.72 g·pot-1) was attained when the ratio of stress concentration for exogenous P, Zn, and Cd[ω(Cd):ω(Zn):ω(P)] was 1:10:200. Furthermore, the Cd content in the edible part was also lower than the national standard requirement of 50 μg·kg-1for Cd in green leafy vegetables (GB 2762-2017). In addition, the accumulation of Cd was further decreased when the proportion of P and Zn was increased, along with a decreased yield of the vegetable. Therefore, a proper application of P and Zn fertilizers could simultaneously reduce Cd accumulation and increase crop yield and thus contribute to achieving safe vegetable production. |
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