施苯菌灵抑制丛枝菌根真菌对污染土壤-玉米系统镉迁移的影响

【目的】为探讨土壤丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)对污染土壤-作物系统Cd迁移行为的影响。【方法】采用云南兰坪铅锌矿周边重金属污染的土壤,开展室内试验,施杀真菌剂 (苯菌灵) 特异性抑制土壤土著AMF,研究抑制AMF对玉米生长、Cd含量与累积量、土壤Cd淋溶流失的影响。【结果】结果表明:(1)施苯菌灵显著抑制土壤AMF生长,导致AMF侵染率、孢子数、土壤球囊霉素相关蛋白(Glomalin related soil protein,GRSP)含量显著降低；并显著影响玉米生长与矿质营养,导致玉米地上部生物量、叶绿素与磷含量增加,而地上部氮钾含量降低。(2)施苯菌灵促进Cd向玉米根部和地上部迁移,主要富集在玉米地上部,导致玉米地上部的Cd含量和累积量显著增加。(3)施苯菌灵导致10 cm和20 cm壤中流的Cd浓度显著增加。此外,土壤GRSP含量与玉米地上部Cd累积量和壤中流的Cd流失浓度均呈极显著负相关。【结论】研究结果表明,土壤土著AMF有助于抑制土壤Cd向植株地上部迁移,减少壤中流Cd的流失浓度,降低污染土壤-作物系统Cd的环境迁移。

Effect of Benomyl on Inhibition of Arbuscular Mycorrhizal Fungi on Cadmium Migration in Polluted Soil Corn System

To investigate the effect of soil arbuscular mycorrhizal fungi (AMF) on Cd migration in contaminated soil-crop system.The farmland soil polluted by heavy metals around the Lanping Lead Zinc Mine in Yunnan Province was used to carry out indoor experiments. The specific fungicide (benomyl) was applied to inhibit indigenous AMF in soil, and the effects of inhibiting AMF on corn growth, Cd content and accumulation, and soil Cd leaching loss were studied. The results show that: (1) The application of benomyl significantly inhibited the growth of soil AMF, resulting in a significant reduction in the infection rate of AMF, the number of spores, and the content of soil Glomalin related soil protein (GRSP); It also significantly affected the growth and mineral nutrition of maize, leading to an increase in the aboveground biomass, chlorophyll and phosphorus content of maize, while a decrease in the aboveground nitrogen and potassium content. (2) The application of benomyl promoted the migration of Cd to the roots and shoots of maize, mainly concentrated in the shoots of maize, resulting in a significant increase in the content and accumulation of Cd in the shoots of maize.(3) The application of benomyl resulted in a significant increase in Cd concentration in the 10 cm and 20 cm soil streams. In addition, the soil GRSP content was significantly negatively correlated with the accumulation of Cd in the aboveground part of maize and the Cd loss concentration in the soil flow. The research results indicate that indigenous AMF in soil can help inhibit the migration of soil Cd to the aboveground parts of plants, reduce the loss concentration of Cd in soil flow, and reduce the environmental migration of Cd in polluted soil crop systems.