| 基于PLS模型的镉与微塑料复合污染对冬小麦植株生理和土壤理化性质影响 |
| 摘要点击 1078 全文点击 118 投稿时间：2024-03-10 修订日期：2024-05-06 |
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| 中文关键词 冬小麦 镉（Cd） 微塑料（MPs） 复合污染 生理特性 偏最小二乘（PLS）回归模型 |
| 英文关键词 winter wheat cadmium（Cd） microplastics（MPs） combined pollution physiological characteristics partial least squares（PLS） model |
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| 中文摘要 |
| 探究重金属、微塑料及二者复合污染对冬小麦生长、生理生态及土壤理化性质影响效应,确定关键影响因子,为重金属和微塑料污染生理机制阐释以及污染土壤的生态修复提供理论基础. 采用室内土壤盆栽试验,以冬小麦（Triticum aestivum L.）为研究对象,开展土壤重金属镉（Cd）（0 mg·kg-1和5 mg·kg-1）与不同粒径（10 μm和500 μm）和质量分数（0、0.5%、1.0%、5.0%）聚丙烯微塑料（PP-MPs）单一及复合污染对冬小麦生长发育、光合生理、抗氧化酶活性、叶片解剖结构、冠层温度、土壤养分及土壤酶活性影响效应研究. 同时利用偏最小二乘（PLS）回归模型定量分析各理化特性与冬小麦生长指标间关系,确定关键主控因子. 结果表明, 小粒径PP-MPs单一及其与Cd复合污染条件下,冬小麦株高显著降低了10.3%~59.9%,叶面积显著降低了5.8%~94.2%,总生物量显著降低了20.0%~84.0%. 另外,二者污染条件下,小麦叶片光合效率、叶绿素含量等光合特性明显受到抑制. 随两者污染胁迫程度增加,小麦植株群体冠层温度升高,叶片厚度降低；与CK相比,叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）分别提高了13.4%~99.0%、45.5%~122.7%和2.8%~89.2%,且两者间交互效应达极显著水平（P<0.01）. 此外,Cd与PP-MPs胁迫后略微增加了土壤有机质、碱解氮、速效磷和速效钾等养分含量,显著提高了土壤脲酶、酸性磷酸酶和脱氢酶活性. 与单一污染因素相比,Cd与PP-MPs复合污染对冬小麦各指标影响均呈协同抑制效应,且10 μm小粒径抑制效应明显强于500 μm大粒径. PLS模型结果显示,土壤酸性磷酸酶为Cd与10 μm小粒径PP-MPs复合污染胁迫下影响冬小麦生长发育指标变化的关键主控因子,土壤速效磷则为500 μm大粒径PP-MPs关键影响因子. 研究结果对于评估土壤-植株系统中重金属Cd与MPs复合污染的生态效应提供参考借鉴. |
| 英文摘要 |
| To explore the effects of heavy metals, microplastics, and their combined action on the growth, physiological ecology, and soil physicochemical properties of winter wheat （Triticum aestivum L.）, we sought to identify the major controlling factors and thus to provide a theoretical basis for revealing the physiological ecology response mechanism and ecological restoration of contaminated soil. Soil culture treatment experiments were conducted to study the effects of the heavy metal cadmium （Cd） （0 mg·kg-1 and 5 mg·kg-1） and polypropylene microplastics （PP-MPs） with different particle sizes （10 μm and 500 μm） and mass concentration （0, 0.5%, 1.0%, and 5.0%） on winter wheat growth, photosynthetic physiology, antioxidant enzyme activity, leaf anatomy, canopy temperature, soil nutrients, and soil enzyme activity. Moreover, a partial least squares （PLS） model was used to quantify the relationship between physical and chemical indicators and winter wheat growth status and to identify the major controlling factors. The results showed that the plant height, leaf area, and total biomass of winter wheat decreased by 10.3%-59.9%, 5.8%-94.2%, and 20.0%-84.0%, respectively, under the pollution condition of small particle size PP-MPs alone and combined with Cd. In addition, photosynthetic characteristics, such as photosynthetic efficiency and chlorophyll content of wheat leaves were significantly inhibited under the conditions of both pollutants. With the increase of pollution stress, the canopy temperature of the wheat population increased, and the leaf thickness decreased. Compared with that in CK, the superoxide dismutase （SOD）, peroxidase （POD）, and catalase （CAT） of leaves increased by 13.4%-99.0%, 45.5%-122.7%, and 2.8%-89.2%, respectively, and the interaction between them was extremely significant （P<0.01）. In addition, Cd and PP-MPs also slightly increased the contents of soil organic matter, alkali-hydrolyzed nitrogen, available phosphorus, and available potassium and significantly improved the activities of soil urease, acid phosphatase, and dehydrogenase. In summary, the combined Cd-PP-MPs pollution had synergistic inhibition effects on the above indicators, and the inhibiting effects of 10 μm PP-MPs were significantly stronger than those of 500 μm. PLS results showed that soil acid phosphatase was the key control factor affecting the growth and development indices of winter wheat under the combined pollution stress of Cd and 10 μm PP-MPs, and soil available phosphorus was the key influencing factor of 500 μm large-particle size PP-MPs. The results provide reference for evaluating the ecological effects of heavy metal Cd and MPs combined pollution in the soil-plant system. |
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